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7-2016

Law and Economics, 6th edition
Robert Cooter
Berkeley Law

Thomas Ulen

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http://scholarship.law.berkeley.edu/books/2

Authors’ Note

LAW AND ECONOMICS (pdf 6th edition)

by Robert Cooter and Thomas Ulen

This is a pdf version of the latest version (6th edition) of Law and Economics

by Cooter and Ulen. The ownership of this book has reverted from the publisher to

its authors, so we are posting it online for everyone freely to read or use as a

textbook. After more than thirty years as the field’s leading textbook, it continues to

cover the latest developments in the economic analysis of property, torts, contracts,

legal process, and crimes. Each new edition refines the analytical core, incorporates

new applications, and expands previous discussions of empirical legal studies and

behavioral law and economics. We hope that you enjoy reading this book as much as

we enjoyed writing it.

Looking forward to next year, this duet will become an internet symphony

that takes full advantage of the internet revolution in publishing. Improvements

will be posted to the internet continuously in small amounts (7.1, 7.2, 7.3, etc.), until

a new edition appears with large changes (8.0). Not just a textbook, the 7th edition

will have supporting materials, including translations. For updates, join the email

list found by googling “Cooter and Ulen Berkeley Law Repository”. Perhaps you will

have something to contribute to the website. For the best feast, the host supplies the

main course each guest contributes a dish.

Law&Economics

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Abel/Bernanke/Croushore
Macroeconomics*

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Foundations of Economics*

Berck/Helfand
The Economics of the
Environment

Bierman/Fernandez
Game Theory with
Economic Applications

Blanchard
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Blau/Ferber/Winkler
The Economics of Women,
Men and Work

Boardman/Greenberg/Vining/
Weimer

Cost-Benefit Analysis

Boyer
Principles of Transportation
Economics

Branson
Macroeconomic Theory
and Policy

Brock/Adams
The Structure of American
Industry

Bruce
Public Finance and the
American Economy

Carlton/Perloff
Modern Industrial Organization

Case/Fair/Oster
Principles of Economics*

Caves/Frankel/Jones
World Trade and Payments:
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Chapman
Environmental Economics:
Theory, Application,
and Policy

Cooter/Ulen
Law & Economics

Downs
An Economic Theory of
Democracy

Ehrenberg/Smith
Modern Labor Economics

Ekelund/Ressler/Tollison
Economics*

Farnham
Economics for Managers

Folland/Goodman/Stano
The Economics of Health
and Health Care

Fort
Sports Economics

Froyen
Macroeconomics

Fusfeld
The Age of the Economist

Gerber
International Economics*

Gordon
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Greene
Econometric Analysis

Gregory
Essentials of Economics

Gregory/Stuart
Russian and Soviet Economic
Performance and Structure

Hartwick/Olewiler
The Economics of Natural
Resource Use

Heilbroner/Milberg
The Making of the Economic
Society

Heyne/Boettke/Prychitko
The Economic Way of Thinking

Hoffman/Averett
Women and the Economy:
Family, Work, and Pay

Holt
Markets, Games and Strategic
Behavior

Hubbard/O’Brien
Economics*

Money, Banking, and the
Financial System*

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Theory

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A Health Economics Primer

Keat/Young
Managerial Economics

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for Economics

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International Economics:
Theory & Policy*

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The Demand for Money

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The Economics of Sports

Leeds/von Allmen/Schiming
Economics*

Lipsey/Ragan/Storer
Economics*

Lynn
Economic Development: Theory
and Practice for a Divided
World

Miller
Economics Today*

Understanding Modern
Economics

Miller/Benjamin
The Economics of Macro
Issues

Miller/Benjamin/North
The Economics of Public Issues

Mills/Hamilton
Urban Economics

Mishkin
The Economics of Money,
Banking, and Financial
Markets*

The Economics of Money,
Banking, and Financial
Markets, Business School
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Macroeconomics: Policy
and Practice*

Murray
Econometrics: A Modern
Introduction

Nafziger
The Economics of Developing
Countries

O’Sullivan/Sheffrin/Perez
Economics: Principles,
Applications, and Tools*

Parkin
Economics*

Perloff
Microeconomics*

Microeconomics: Theory
and Applications with
Calculus*

Perman/Common/McGilvray/Ma
Natural Resources and
Environmental Economics

Phelps
Health Economics

Pindyck/Rubinfeld
Microeconomics*

Riddell/Shackelford/Stamos/
Schneider

Economics: A Tool for
Critically
Understanding Society

Ritter/Silber/Udell
Principles of Money, Banking &
Financial Markets*

Roberts
The Choice: A Fable of Free
Trade and Protection

Rohlf
Introduction to Economic
Reasoning

Ruffin/Gregory
Principles of Economics

Sargent
Rational Expectations and
Inflation

Sawyer/Sprinkle
International Economics

Scherer
Industry Structure, Strategy,
and Public Policy

Schiller
The Economics of Poverty and
Discrimination

Sherman
Market Regulation

Silberberg
Principles of Microeconomics

Stock/Watson
Introduction to Econometrics

Introduction to Econometrics,
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Studenmund
Using Econometrics:
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Environmental and Natural
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Weil
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S I X T H E D I T I O N

Law&
Economics

ROBERT COOTER
University of California, Berkeley

THOMAS ULEN
University of Illinois, Urbana-Champaign

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Library of Congress Cataloging-in-Publication Data
Cooter, Robert.

Law and economics / Robert Cooter, Thomas Ulen.—6th ed.
p. cm.

Rev. ed. of: Law & economics / Robert Cooter, Thomas Ulen.
Includes index.
ISBN 978-0-13-254065-0
1. Law and economics. I. Ulen, Thomas. II. Cooter, Robert. Law & economics. III. Title.
K487.E3C665 2011
340’.11—dc22

2010049060
10 9 8 7 6 5 4 3 2 1

ISBN-10: 0-13-254065-7
ISBN-13: 978-0-13-254065-0

vii

Preface x

1. An Introduction to Law and Economics 1

I. What Is the Economic Analysis of Law? 3

II. Some Examples 4

III. The Primacy of Efficiency Over Distribution in Analyzing
Private Law 7

IV. Why Should Lawyers Study Economics? Why Should Economists
Study Law? 9

V. The Plan of This Book 10

2. A Brief Review of Microeconomic Theory 11

I. Overview: The Structure of Microeconomic Theory 11

II. Some Fundamental Concepts: Maximization, Equilibrium,
and Efficiency 12

III. Mathematical Tools 14

IV. The Theory of Consumer Choice and Demand 18

V. The Theory of Supply 26

VI. Market Equilibrium 28

VII. Game Theory 33

VIII. The Theory of Asset Pricing 37

IX. General Equilibrium and Welfare Economics 37

X. Decision Making Under Uncertainty: Risk and Insurance 43

XI. Profits and Growth 49

XII. Behavioral Economics 50

3. A Brief Introduction to Law and Legal Institutions 55

I. The Civil Law and the Common Law Traditions 56

II. The Institutions of the Federal and the State Court Systems in the
United States 59

III. The Nature of a Legal Dispute 62

IV. How Legal Rules Evolve 64

Contents

4. An Economic Theory of Property 70

I. The Legal Concept of Property 73

II. Bargaining Theory 74

III. The Origins of the Institution of Property: A Thought
Experiment 76

IV. An Economic Theory of Property 81

V. How are Property Rights Protected? 94

VI. What Can be Privately Owned?—Public and Private Goods 102

VII. What May Owners Do with Their Property? 105

VIII. On Distribution 106

Appendix: The Philosophical Concept of Property 109

5. Topics in the Economics of Property Law 112

I. What can be Privately Owned? 112

II. How are Property Rights Established and Verified? 143

III. What May Owners Do with Their Property? 156

IV. What are the Remedies for the Violation of Property Rights? 166

6. An Economic Theory of Tort Law 187

I. Defining Tort Law 189

II. An Economic Theory of Tort Liability 199

Appendix: Liability and Symmetry 228

7. Topics in the Economics of Tort Liability 230

I. Extending the Economic Model 230

II. Computing Damages 253

III. An Empirical Assessment of the U.S. Tort Liability System 261

8. An Economic Theory of Contract Law 276

I. Bargain Theory: An Introduction to Contracts 277

II. An Economic Theory of Contract Enforcement 283

III. An Economic Theory of Contract Remedies 287

IV. Economic Interpretation of Contracts 291

V. Relational Contracts: The Economics of the Long-Run 299

viii Contents

9. Topics in the Economics of Contract Law 307

I. Remedies as Incentives 307

II. Formation Defenses and Performance Excuses 341

Appendix: Mathematical Appendix 373

10. An Economic Theory of the Legal Process 382

I. The Goal of the Legal Process: Minimizing Social Costs 384

II. Why Sue? 386

III. Exchange of Information 391

IV. Settlement Bargaining 399

V. Trial 403

VI. Appeals 410

11. Topics in the Economics of the Legal Process 419

I. Complaints, Lawyers, Nuisances, and Other Issues
in the Legal Process 419

II. An Empirical Assessment of the Legal Process 442

12. An Economic Theory of Crime and Punishment 454

I. The Traditional Theory of Criminal Law 455

II. An Economic Theory of Crime and Punishment 460

13. Topics in the Economics of Crime and Punishment 485

I. Crime and Punishment in the United States 485

II. Does Punishment Deter Crime? 491

III. Efficient Punishment 501

IV. The Death Penalty 510

V. The Economics of Addictive Drugs and Crime 518

VI. The Economics of Handgun Control 522

VII. Explaining the Decline in Crime in the United States 526

Case Index 533

Name Index 535

Subject Index 539

Contents ix

x

Preface

This sixth edition of Law and Economics arrives as the field celebrates its
(roughly) 30th birthday. What began as a scholarly niche has grown into one of
the most widely used tools of legal analysis. The subject has spread from the

United States to many other countries. As scholarship deepens, the concepts in the core
of law and economics become clearer and more stable, and new applications develop
from the core like biological species evolving through specialization. With each new
edition, we continue to refine the explanation of the analytical core and to incorporate
new applications selectively as space permits. This edition expands previous discus-
sions of empirical legal studies and behavioral law and economics. As we incorporate
new material and respond to the suggestions that so many people have sent us, the book
feels more like a symphony and less like a duet. We hope that you enjoy reading this
book as much as we enjoyed writing it.

The book continues to cover the economic analysis of the law of property, torts,
contracts, the legal process and crimes. Instructors and students who have used previ-
ous editions will notice that we have reversed the order in which we treat torts and con-
tracts, and we have divided the material on legal process into two chapters—one on
theory and one on topics—in parallel with our treatment of all the other substantive ar-
eas of the law. Below we describe what is new in this edition, followed by an account
of the book’s website.

New to This Edition
The Sixth Edition has been revised and updated to reflect the latest developments in
law and economics. Major changes to the text are as follows:

• Tables and graphs have been updated.
• New boxes and suggested readings have been added throughout the text.
• Web Notes have been updated and added.
• Chapter 6 contains additional information on liability and customs in trade.
• Chapter 8 improves the explanation of contractual commitments through a better

representation of the principal-agent problem.

• Chapter 9 now includes new material on lapses, vicarious liability, incomprehensi-
ble harms, punitive damages, mass torts, medical malpractice, and some behav-
ioral aspects of contract remedies.

• Chapter 10 contains a new treatment of decision making by potential litigants and
their lawyers, and new figures and decision trees.

• Chapter 11, a new chapter, combines new material on the legal process and an
updated empirical assessment of various aspects of legal disputes.

• Chapter 12 now contains the theoretical material on crime and punishment, updated
and clarified.

• Chapter 13 applies the theoretical insights of the previous chapter to wide-ranging
policy issues in criminal justice and updates data and information from previous
editions.

Online Resources
The Companion Website presents a wealth of supplementary materials to help in
teaching and learning law and economics. “Web Notes” throughout the book indi-
cate the points at which there is additional material on the Companion Website at
www.pearsonhighered.com/cooter_ulen. These notes extend the text presentations,
provide guides and links to new articles and books, and contain excerpts from cases.
We also include some examples of examinations and problem sets.

An updated Instructor’s Manual, reflective of changes to the new edition, will be
available for instructors’ reference. The Instructor’s Manual is available for download
on the Instructor’s Resource center at www.pearsonhighered.com/irc.

Acknowledgments
We continue to be extremely grateful to our colleagues at Boalt Hall of the
University of California, Berkeley, and at the University of Illinois College of Law
for the superb scholarly environments in which we work. Our colleagues have been
extremely generous with their time in helping us to understand the law better. And
in one of the great, ongoing miracles of the academic enterprise, we continue to
learn much from the students whom we have the pleasure to teach at Berkeley,
Illinois, and elsewhere.

We should also thank the many colleagues and students at other universities who
have used our book in their classes and sent us many helpful suggestions about how to
improve the book. We particularly thank Joe Kennedy of Georgetown, who has given
us remarkably thorough and singularly helpful comments on improvements in the text.

We’d like to thank the following reviewers for their thoughtful commentary on the fifth
edition: Howard Bodenhorn, J. Lon Carlson, Joseph M. Jadlow, and Mark E. McBride.

We would also like to thank those who have provided research assistance for this
sixth edition: Theodore Ulen, Timothy Ulen, and Brian Doxey. And, also, for their
long-time support and help: Jan Crouter, Dhammika Dharmapala, Lee Ann Fennell,

Preface xi

Nuno Garoupa, John Lopatka, Richard McAdams, Andy Morriss, Tom Nonnenmacher,
Noel Netusil, Dan Vander Ploeg, and David Wishart.

Finally, we owe particular thanks to our assistants, Ida Ng at Boalt Hall and Sally
Cook at the University of Illinois College of Law. They do many big things to help us
get our work done, as well as many little things without which much of our work would
be impossible to do. Thanks so much.

ROBERT D. COOTER
Berkeley, CA

THOMAS S. ULEN
Champaign, IL

November, 2010

xii Preface

For the rational study of the law the black-letter man may be the man of the present,
but the man of the future is the man of statistics and the master of economics. . . . We
learn that for everything we have to give up something else, and we are taught to set
the advantage we gain against the other advantage we lose, and to know what we are
doing when we elect.

Oliver Wendell Holmes.
THE PATH OF THE LAW, 10 HARV. L. REV. 457, 469, 474 (1897)1

To me the most interesting aspect of the law and economics movement has been its as-
piration to place the study of law on a scientific basis, with coherent theory, precise
hypotheses deduced from the theory, and empirical tests of the hypotheses. Law is a
social institution of enormous antiquity and importance, and I can see no reason why
it should not be amenable to scientific study. Economics is the most advanced of the
social sciences, and the legal system contains many parallels to and overlaps with the
systems that economists have studied successfully.

Judge Richard A. Posner, in MICHAEL FAURE &
ROGER VAN DEN BERGH, EDS., ESSAYS IN LAW AND ECONOMICS (1989)

UNTIL RECENTLY, LAW confined the use of economics to antitrust law, regulated in-
dustries, tax, and some special topics like determining monetary damages. In
these areas, law needed economics to answer such questions as “What is the de-

fendant’s share of the market?”; “Will price controls on automobile insurance reduce
its availability?”; “Who really bears the burden of the capital gains tax?”; and “How
much future income did the children lose because of their mother’s death?”

Beginning in the early 1960s, this limited interaction changed dramatically when
the economic analysis of law expanded into the more traditional areas of the law, such
as property, contracts, torts, criminal law and procedure, and constitutional law.2 This

1

1 An Introduction to Law
and Economics

1 Our citation style is a variant of the legal citation style most commonly used in the United States. Here is
what the citation means: the author of the article from which the quotation was taken is Oliver Wendell
Holmes; the title of the article is “The Path of the Law”; and the article may be found in volume 10 of the
Harvard Law Review, which was published in 1897, beginning on page 457. The quoted material comes
from pages 469 and 474 of that article.

2 The modern field is said to have begun with the publication of two landmark articles—Ronald H. Coase,
The Problem of Social Cost, 3 J. L. & ECON. 1 (1960) and Guido Calabresi, Some Thoughts on Risk
Distribution and the Law of Torts, 70 YALE L.J. 499 (1961).

2 C H A P T E R 1 An Introduction to Law and Economics

new use of economics in the law asked such questions as, “Will private ownership of
the electromagnetic spectrum encourage its efficient use?”; “What remedy for breach
of contract will cause efficient reliance on promises?”; “Do businesses take too much
or too little precaution when the law holds them strictly liable for injuries to con-
sumers?”; and “Will harsher punishments deter violent crime?”

Economics has changed the nature of legal scholarship, the common understanding
of legal rules and institutions, and even the practice of law. As proof, consider these in-
dicators of the impact of economics on law. By 1990 at least one economist was on the
faculty of each of the top law schools in North America and some in Western Europe.
Joint degree programs (a Ph.D. in economics and a J.D. in law) exist at many prominent
universities. Law reviews publish many articles using the economic approach, and there
are several journals devoted exclusively to the field.3 An exhaustive study found that ar-
ticles using the economic approach are cited in the major American law journals more
than articles using any other approach.4 Many law school courses in America now in-
clude at least a brief summary of the economic analysis of law in question. Many sub-
stantive law areas, such as corporation law, are often taught from a law-and-economics
perspective.5 By the late 1990s, there were professional organizations in law and eco-
nomics in Asia, Europe, Canada, the United States, Latin America, Australia, and else-
where. The field received the highest level of recognition in 1991 and 1992 when
consecutive Nobel Prizes in Economics6 were awarded to economists who helped to
found the economic analysis of law—Ronald Coase and Gary Becker. Summing this up,
Professor Bruce Ackerman of the Yale Law School described the economic approach to
law as “the most important development in legal scholarship of the twentieth century.”

The new field’s impact extends beyond the universities to the practice of law and
the implementation of public policy. Economics provided the intellectual foundations
for the deregulation movement in the 1970s, which resulted in such dramatic changes
in America as the dissolution of regulatory bodies that set prices and routes for airlines,
trucks, and railroads. Economics also served as the intellectual force behind the revolu-
tion in antitrust law in the United States in the 1970s and 1980s. In another policy area,
a commission created by Congress in 1984 to reform criminal sentencing in the federal
courts explicitly used the findings of law and economics to reach some of its results.
Furthermore, several prominent law-and-economics scholars have become federal
judges and use economic analysis in their opinions—Associate Justice Stephen Breyer
of the U.S. Supreme Court; Judge Richard A. Posner and Judge Frank Easterbrook of
the U.S. Court of Appeals for the Seventh Circuit; Judge Guido Calabresi of the U.S.

3 For example, the Journal of Law and Economics began in 1958; the Journal of Legal Studies in 1972;
Research in Law and Economics, the International Review of Law and Economics, and the Journal of Law,
Economics, and Organization in the 1980s; and the Journal of Empirical Legal Studies in 2004.

4 William M. Landes & Richard A. Posner, The Influence of Economics on Law: A Quantitative Study, 36 J.
L. & ECON. 385 (1993).

5 See, e.g., STEPHEN M. BAINBRIDGE, CORPORATION LAW AND ECONOMICS (2002).
6 The full name of the Nobel Prize in Economics is the Bank of Sweden Prize in the Economic Sciences in

Memory of Alfred Nobel. See our book’s website for a full list of those who have won the Nobel Prize and
brief descriptions of their work.

I. What Is the Economic Analysis of Law? 3

Court of Appeals for the Second Circuit; Judge Douglas Ginsburg, and former Judge
Robert Bork of the U.S. Court of Appeals for the D.C. Circuit; and Judge Alex
Kozinski of the U.S. Court of Appeals for the Ninth Circuit.

I. What Is the Economic Analysis of Law?
Why has the economic analysis of law succeeded so spectacularly, especially in

the United States but increasingly also in other countries?7 Like the rabbit in Australia,
economics found a vacant niche in the “intellectual ecology” of the law and rapidly
filled it. To explain the niche, consider this classical definition of some kinds of laws:
“A law is an obligation backed by a state sanction.”

Lawmakers often ask, “How will a sanction affect behavior?” For example, if
punitive damages are imposed upon the maker of a defective product, what will happen
to the safety and price of the product in the future? Or will the amount of crime de-
crease if third-time offenders are automatically imprisoned? Lawyers answered such
questions in 1960 in much the same way as they had 2000 years earlier—by consulting
intuition and any available facts.

Economics provided a scientific theory to predict the effects of legal sanctions on
behavior. To economists, sanctions look like prices, and presumably, people respond to
these sanctions much as they respond to prices. People respond to higher prices by
consuming less of the more expensive good; presumably, people also respond to more
severe legal sanctions by doing less of the sanctioned activity. Economics has mathe-
matically precise theories (price theory and game theory) and empirically sound
methods (statistics and econometrics) for analyzing the effects of the implicit prices
that laws attach to behavior.

Consider a legal example. Suppose that a manufacturer knows that his product
will sometimes injure consumers. How safe will he make the product? For a profit-
maximizing firm, the answer depends upon three costs: First, the cost of making the
product safer, which depends on its design and manufacture; second, the manufac-
turer’s legal liability for injuries to consumers; and third, the extent to which injuries
discourage consumers from buying the product. The profit-maximizing firm will adjust
safety until the cost of additional safety equals the benefit from reduced liability and
higher consumer demand for the good.

Economics generally provides a behavioral theory to predict how people respond to
laws. This theory surpasses intuition just as science surpasses common sense. The re-
sponse of people is always relevant to making, revising, repealing, and interpreting laws.
A famous essay in law and economics describes the law as a cathedral—a large, ancient,
complex, beautiful, mysterious, and sacred building.8 Behavioral science resembles the
mortar between the cathedral’s stones, which support the structure everywhere.

7 See Nuno Garoupa & Thomas S. Ulen, The Market for Legal Innovation: Law and Economics in Europe
and the United States, 59 ALA. L. REV. 1555 (2008).

8 Guido Calabresi & A. Douglas Melamed, Property Rules, Liability Rules, and Inalienability: One View of
the Cathedral, 85 HARV. L. REV. 1089 (1972).

4 C H A P T E R 1 An Introduction to Law and Economics

A prediction can be neutral or loaded with respect to social values. A study finds
that higher fines for speeding on the highway will presumably cause less of it. Is this
good or bad on balance? The finding does not suggest an answer. In contrast, suppose
that a study proves that the additional cost of collecting higher fines exceeds the result-
ing benefit from fewer accidents, so a higher fine is “inefficient.” This finding suggests
that a higher fine would be bad. Efficiency is always relevant to policymaking, because
public officials never advocate wasting money. As this example shows, besides neutral
predictions, economics makes loaded predictions. Judges and other officials need a
method for evaluating laws’ effects on important social values. Economics provides
such a method for efficiency.

Besides efficiency, economics predicts the effects of laws on another important value:
the distribution of income. Among the earliest applications of economics to public policy
was its use to predict who really bears the burden of alternative taxes. More than other so-
cial scientists, economists understand how laws affect the distribution of income across
classes and groups. While almost all economists favor changes that increase efficiency,
some economists take sides in disputes about distribution and others do not take sides.

Instead of efficiency or distribution, people in business mostly talk about profits.
Much of the work of lawyers aims to increase the profits of businesses, especially by
helping businesses to make deals, avoid litigation, and obey regulations. These three ac-
tivities correspond to three areas of legal practice in large law firms: transactions, litiga-
tion, and regulation. Efficiency and profitability are so closely related that lawyers can
use the efficiency principles in this book to help businesses make more money. Economic
efficiency is a comprehensive measure of public benefits that include the profits of firms,
the well-being of consumers, and the wages of workers. The logic of maximizing the
comprehensive measure (efficiency) is very similar to the logic of maximizing one of its
components (profits). A good legal system keeps the profitability of business and the wel-
fare of people aligned, so that the pursuit of profits also benefits the public.

II. Some Examples
To give you a better idea of what law and economics is about, we turn to some ex-

amples based upon classics in the subject. First, we try to identify the implicit price that
the legal rule attaches to behavior in each example. Second, we predict the conse-
quences of variations in that implicit price. Finally, we evaluate the effects in terms of
efficiency and, where possible, distribution.

Example 1: A commission on reforming criminal law has identified cer-
tain white-collar crimes (such as embezzling money from one’s employer) that are
typically committed after rational consideration of the potential gain and the risk
of getting caught and punished. After taking extensive testimony, much of it from
economists, the commission decides that a monetary fine is the appropriate pun-
ishment for these offenses, not imprisonment. The commission wants to know,
“How high should the fine be?”

The economists who testified before the commission have a framework for an-
swering this question. The commission focused on rational crimes that seldom occur
unless the expected gain to the criminal exceeds the expected cost. The expected cost

II. Some Examples 5

depends upon two factors: the probability of being caught and convicted and the sever-
ity of the punishment. For our purposes, define the expected cost of crime to the crimi-
nal as the product of the probability of a fine times its magnitude.

Suppose that the probability of punishment decreases by 5 percent and the magni-
tude of the fine increases by 5 percent. In that case, the expected cost of crime to the
criminal roughly remains the same. Because of this, the criminal will presumably re-
spond by committing the same amount of crime. (In Chapter 12 we shall explain the
exact conditions for this conclusion to be true.) This is a prediction about how illegal
behavior responds to its implicit price.

Now we evaluate this effect with respect to economic efficiency. When a decrease in
the probability of a fine offsets an increase in its magnitude, the expected cost of crime
remains roughly the same for criminals, but the costs of crime to the criminal justice sys-
tem may change. The costs to the criminal justice system of increasing a fine’s probabil-
ity include expenditures on apprehending and prosecuting criminals—for example, on
the number and quality of auditors, tax and bank examiners, police, prosecuting attor-
neys, and the like. While the cost of increasing the probability of catching and convicting
white-collar criminals is relatively high, administering fines is relatively cheap. These
facts imply a prescription for holding white-collar crime down to any specified level at
least cost to the state: Invest little in apprehending and prosecuting offenders, and fine se-
verely those who are apprehended. Thus, the commission might recommend very high
monetary fines in its schedule of punishments for white-collar offenses.

Professor Gary Becker derived this result in a famous paper cited by the Nobel Prize
Committee in its award to him. Chapters 12 and 13 discuss these findings in detail.

Example 2: An oil company contracts to deliver oil from the Middle East
to a European manufacturer. Before the oil is delivered, war breaks out and the oil
company cannot perform as promised. The lack of oil causes the European manu-
facturer to lose money. The manufacturer brings an action (that is, files a lawsuit)
against the oil company for breach of contract. The manufacturer asks the court to
award damages equal to the money that it lost. The contract is silent about the risk
of war, so that the court cannot simply read the contract and resolve the dispute on
the contract’s own terms. The oil company contends that it should be excused from
performance because it could do nothing about the war and neither of the con-
tracting parties foresaw it. In resolving the suit, the court must decide whether to
excuse the oil company from performance on the ground that the war made the
performance “impossible,” or to find the oil company in breach of contract and to
require the oil company to compensate the manufacturer for lost profits.9

War is a risk of doing business in the Middle East that one of the parties to the con-
tract must bear, and the court must decide which one it is. What are the consequences
of different court rulings? The court’s decision simultaneously accomplishes two
things. First, it resolves the dispute between the litigants—“dispute resolution.”
Second, it guides future parties who are in similar circumstances about how courts
might resolve their dispute—“rule creation.” Law and economics is helpful in resolving

9 For a full discussion of the cases on which this example is based, see Richard A. Posner & Andrew
Rosenfield, Impossibility and Related Doctrines in Contract Law, 6 J. LEGAL STUD. 88 (1977).

6 C H A P T E R 1 An Introduction to Law and Economics

disputes, but it particularly shines in creating rules. Indeed, a central question in this
book is, “How will the rule articulated by the lawmaker to resolve a particular dispute
affect the behavior of similarly situated parties in the future?” And, “Is the predicted
behavior desirable?”

The oil company and the manufacturer can take precautions against war in the
Middle East, although neither of them can prevent it. The oil company can sign backup
contracts for delivery of Venezuelan oil, and the manufacturer can store oil for emer-
gency use. Efficiency requires the party to take precaution who can do so at least cost.
Is the oil company or the manufacturer better situated to take precautions against war?
Since the oil company works in the Middle East, it is probably better situated than a
European manufacturer to assess the risk of war in that region and to take precautions
against it. For the sake of efficiency, the court might hold the oil company liable and
cite the principle that courts will allocate risks uncovered in a contract to the party who
can bear them at least cost. This is the principle of the least-cost risk-bearer,10 which is
consistent with some decisions in cases that arose from the Middle Eastern war of
1967. Chapters 8 and 9 consider this principle’s foundation.

Example 3: Eddie’s Electric Company emits smoke that dirties the wash
hanging at Lucille’s Laundry. Eddie’s can completely abate the pollution by in-
stalling scrubbers on its stacks, and Lucille’s can completely exclude the smoke by
installing filters on its ventilation system. Installing filters is cheaper than installing
scrubbers. No one else is affected by this pollution because Eddie’s and Lucille’s
are near to each other and far from anyone else. Lucille’s initiates court proceed-
ings to have Eddie’s declared to be a “nuisance.” If the action succeeds, the court
will order Eddie’s to abate its pollution. Otherwise, the court will not intervene in
the dispute. What is the appropriate resolution of this dispute?

Efficiency requires Lucille’s to install filters, which is cheaper than Eddie’s in-
stalling scrubbers. How can the court produce this result? The answer depends on
whether or not Eddie’s and Lucille’s can cooperate. First, assume that Eddie’s and
Lucille’s cannot bargain together or cooperate. If Lucille’s wins the action and the court
orders Eddie’s to abate the pollution, Eddie’s will have to install scrubbers, which is ef-
ficient. However, if Lucille’s loses the action, then Lucille’s will have to install filters,
which is inefficient. Consequently, it is efficient for Lucille’s to lose the action.

Now, consider how the analysis changes if Eddie’s and Lucille’s can bargain together
and cooperate. Their joint profits (the sum of the profits of Eddie’s and Lucille’s) will be
higher if they choose the cheaper means of eliminating the harm from pollution. When
their joint profits are higher, they can divide the gain between them in order to make both
of them better off. The cheaper means is also the efficient means. Efficiency is achieved
in this example when Lucille’s and Eddie’s bargain together and cooperate, regardless of
the rule of law. Ronald Coase derived this result in a famous paper cited by the Nobel
Prize Committee when he received the award. Chapter 4 elaborates on this famous result.

10 The principle assumes that the entire loss from nonperformance must be allocated by the court to one of
the parties. Alternatively, the court might divide the loss between the parties.

III. The Primacy of Efficiency Over Distribution in Analyzing Private Law 7

III. The Primacy of Efficiency Over Distribution
in Analyzing Private Law

We explained that economists are experts on two policy values—efficiency and
distribution. The stakes in most legal disputes have monetary value. Deciding a legal
dispute almost always involves allocating the stakes between the parties. The decision
about how much of the stakes each party gets creates incentives for future behavior, not
just for the parties to this dispute but also for everyone who is similarly situated. In this
book we use these incentive effects to make predictions about the consequences of le-
gal decisions, policies, rules, and institutions. In evaluating these consequences, we
will focus on efficiency rather than distribution. Why?

By making a rule, the division of the stakes in a legal dispute affects all similarly
situated people. If a plaintiff in a case is a consumer of a particular good, an investor in
a particular stock, or the driver of a car, then a decision for the plaintiff may benefit
everyone who consumes this good, invests in this stock, or drives a car. Most propo-
nents of income redistribution, however, have something else in mind. Instead of con-
templating distribution to consumers, investors, or drivers, advocates of income
redistribution usually target social groups, such as the poor, women, or minorities.
Some people passionately advocate government redistribution of income by class, gen-
der, or race for the sake of social justice. A possible way to pursue redistribution is
through private law—the law of property, contracts, and torts. According to this philos-
ophy, courts should interpret or make private laws to redistribute income to deserving
groups of people. For example, if consumers are poorer on average than investors, then
courts should interpret liability rules to favor consumers and disfavor corporations.

This book rejects the redistributive approach to private law. Pursuing redistributive
goals is an exceptional use of private law that special circumstances may justify but that
ought not be the usual use of private law. Here is why. Like the rest of the population,
economists disagree among themselves about redistributive ends. However, economists
generally agree about redistributive means. By avoiding waste, efficient redistribution
benefits everyone relative to inefficient redistribution. By avoiding waste, efficient re-
distribution also builds support for redistribution. For example, people are more likely
to donate to a charitable organization that efficiently redistributes income than to one
that spends most of its revenue on administration.

A piquant example will help you to appreciate the advantages of efficient redistri-
bution. Assume that a desert contains two oases, one of which has ice cream and the
other has none. The advocates of social justice who favor redistribution obtain control
over the state and declare that the first oasis should share its ice cream with the second
oasis. In response, the first oasis fills a large bowl with ice cream and sends a youth
running across the desert carrying the bowl to the second oasis. The hot sun melts some
of the ice cream, so the first oasis gives up more ice cream than the second oasis re-
ceives. The melted ice cream represents the cost of redistribution. People who disagree
vehemently about how much ice cream the first oasis should give to the second oasis
may agree that a fast runner should transport it. Also they might agree to choose an
honest runner who will not eat the ice cream along the route.

8 C H A P T E R 1 An Introduction to Law and Economics

Many economists believe that progressive taxation and social welfare programs—
the “tax-and-transfer system,” as it is usually called—can accomplish redistributive
goals in modern states more efficiently than can be done through modifying or reshuf-
fling private legal rights. There are several reasons why reshuffling private legal rights
resembles giving the ice cream to a slow runner.

First, the income tax precisely targets inequality, whereas redistribution by private
legal rights relies on crude averages. To illustrate, assume that courts interpret a law to
favor consumers over corporations in order to redistribute income from rich to poor.11

“Consumers” and “investors” imperfectly correspond to “poor” and “rich.” Consumers
of Ferrari automobiles, skiing vacations, and the opera tend to be relatively rich. Many
small businesses are organized as corporations. Furthermore, the members of unions
with good pension plans own the stocks of large companies. By taxing income progres-
sively, law distinguishes more precisely between rich and poor than by taking the indi-
rect approach of targeting “consumers” and “investors.”

Second, the distributive effects of reshuffling private rights are hard to predict. To
illustrate, the courts cannot be confident that holding a corporation liable to its con-
sumers will reduce the wealth of its stockholders. Perhaps the corporation will pass on
its higher costs to consumers in the form of higher prices, in which case the court’s
holding will redistribute costs from some consumers to other consumers.

Third, the transaction costs of redistribution through private legal rights are typi-
cally high. To illustrate, a plaintiff’s attorney working on a contingency fee in the
United States routinely charges one-third of the judgment. If the defendant’s attorney
collects a similar amount in hourly fees, then attorneys for the two sides will absorb
two-thirds of the stakes in dispute. The tax-and-transfer system is more efficient.

Besides these three reasons, there is a fourth: Redistribution by private law distorts
the economy more than progressive taxation does. In general, relying on broad-based
taxes, rather than narrowly focused laws, reduces the distorting effects of redistributive
policies. For example, assume that a law to benefit consumers of tomatoes causes a de-
cline in the return enjoyed by investors in tomato farms. Investors will respond by with-
drawing funds from tomato farms and investing in other businesses. Consequently, the
supply of tomatoes will be too small and consumers will pay too high a price for them.
This law distorts the market for tomatoes.

For these reasons and more, economists who favor redistribution and economists
who oppose it can agree that private legal rights are usually the wrong way to pursue
distributive justice. Unfortunately, lawyers without training in economics seldom ap-
preciate these facts.

We have presented several reasons against basing private law on redistributive goals.
Specifically, we discussed imprecise targeting, unpredictable consequences, high transac-
tion costs, and distortions in incentives. For these reasons, the general principles of private
law cannot rest on income redistribution. (In special circumstances, however, a private law
can redistribute relatively efficiently, such as a well-designed law giving crippled people
the right to sue employers for not providing wheelchair access to the workplace.)

11 Courts might always find in favor of the individual consumer when he or she sues a corporation regarding
liability for harms arising in the use of the corporation’s products.

IV. Why Should Lawyers Study Economics? Why Should Economists Study Law? 9

Web Note 1.1

Besides efficiency, what other policy values should matter to making law and
applying it? In Fairness Versus Welfare (2002), Louis Kaplow and Steven
Shavell of the Harvard Law School say “None.” Others disagree. See Chris
Sanchirico, Deconstructing the New Efficiency Rationale, 86 CORNELL L. REV.
1005 (2001), and Daniel Farber, What (If Anything) Can Economics Say About
Equity?, 101 MICH. L. REV. 1791 (2003).

There is a more complete discussion of this literature under Chapter 1 at
the website for this book and links to additional sites of interest.

IV. Why Should Lawyers Study Economics? Why Should
Economists Study Law?

The economic analysis of law unites two great fields and facilitates understanding
each of them. You probably think of laws as promoting justice; indeed, many people can
think in no other way. Economics conceives of laws as incentives for changing behavior
(implicit prices) and as instruments for policy objectives (efficiency and distribution).
However, economic analysis often takes for granted such legal institutions as property
and contract, which dramatically affect the economy. Thus, differences in laws cause
capital markets to be organized differently in Japan, Germany, and the United States.
Failures in financial laws and contracting contributed to the banking collapse of 2008 in
the United States and the subsequent recession, which was less severe in Japan and
Germany. Also, the absence of secure property and reliable contracts paralyzes the
economies of some poor nations. Improving the effectiveness of law in poor countries is
important to their economic development. Law needs economics to understand its be-
havioral consequences, and economics needs law to understand the underpinnings of
markets.

Economists and lawyers can also learn techniques from each other. From econo-
mists, lawyers can learn quantitative reasoning for making theories and doing empiri-
cal research. From lawyers, economists can learn to persuade ordinary people—an art

Stern Warning for Students

If you are like most students who read this book—scholars of the highest moral caliber—you
need not upset yourself by reading the rest of this paragraph. If you are one of those wicked
students—we get a few every year—here is a stern warning for you. According to traditional
Chinese beliefs, sinners are tried and punished in ten courts of hell after they die. The sixth court
tries the sin of “abusing books,” punishable by being sawn in half from head to toe. The eighth
court tries the sin of “cheating on exams,” punishable by being cut open and having your intes-
tines ripped out. So don’t you dare abuse this book or cheat on the exams!

10 C H A P T E R 1 An Introduction to Law and Economics

that lawyers continually practice and refine. Lawyers can describe facts and give them
names with moral resonance, whereas economists are obtuse to language too often. If
economists will listen to what the law has to teach them, they will find their models be-
ing drawn closer to what people really care about.

V. The Plan of This Book
To benefit from each other, lawyers must learn some economics and economists

must learn some law. Readers can do so in the next two chapters. Chapter 2 briefly re-
views microeconomic theory. If you are familiar with that theory, then you can read the
material quickly as a review or skim the headings for unfamiliar topics. As a check, you
might try the problems at the end of Chapter 2.

Chapter 3 is an introduction to the law and the legal process, which is essential
reading for those without legal training. We explain how the legal system works, how
the U.S. legal system differs from the rest of the world, and what counts as “law.”

Chapter 4 begins the substantive treatment of the law from an economic viewpoint.
The chapters on substantive legal issues are arranged in pairs. Chapters 4 and 5 focus on
property law; Chapters 6 and 7, on tort law; Chapters 8 and 9, on contract law; Chapters 10
and 11, on resolving legal disputes; and 12 and 13, on criminal law. The first chapter of
each pair explains the basic economic analysis of that area of law, and the second chap-
ter applies the core economic theory to a series of topics. So, Chapter 6 develops an eco-
nomic theory of tort liability, and Chapter 7 applies it to automobile accidents, medical
practice, and defective products. Chapters 4 through 11 deal with laws where the typical
plaintiff in a suit is a private person (“private law”), and Chapters 12 and 13 deal with
criminal law where the plaintiff is the public prosecutor (“public law”).

Suggested Readings

At the end of every chapter we shall list some of the most important writings on the subject.
Please check the website for this book (www.cooter-ulen.com) for additional resources.

BOUCKAERT, BOUDEWIJN, & GERRIT DE GEEST, EDS., ENCYCLOPEDIA OF LAW AND ECONOMICS

(rev. ed., 2011).

DAU-SCHMIDT, KEN, & THOMAS S. ULEN, EDS., A LAW AND ECONOMICS ANTHOLOGY (1997).

MICELI, THOMAS J, THE ECONOMIC APPROACH TO LAW (2d ed. 2008).

NEWMAN, PETER, ED., THE NEW PALGRAVE DICTIONARY OF ECONOMICS AND LAW (3 vols., 1998).

POLINSKY, A. MITCHELL, AN INTRODUCTION TO LAW AND ECONOMICS (3rd, 2003).

POLINSKY, A. MITCHELL, & STEVEN SHAVELL, EDS., HANDBOOK OF LAW AND ECONOMICS, vs. 1
AND 2 (2007).

Posner, Richard A., The Decline of Law as an Autonomous Discipline, 1962–1987,
100 HARV. L. REV. 761 (1987).

POSNER, RICHARD A., ECONOMIC ANALYSIS OF LAW (7th ed., 2007).

SHAVELL, STEVEN, FOUNDATIONS OF THE ECONOMIC ANALYSIS OF LAW (2003).

Practical men, who believe themselves to be quite exempt from any intellectual
influences, are usually the slaves of some defunct economist. . . . It is ideas, not vested
interests, which are dangerous for good or evil.

JOHN MAYNARD KEYNES,
THE GENERAL THEORY OF EMPLOYMENT, INTEREST, AND MONEY (1936)

In this state of imbecility, I had, for amusement, turned my attention to political
economy.

THOMAS DEQUINCEY,
CONFESSIONS OF AN ENGLISH OPIUM EATER (1821)

Economics is the science which studies human behavior as a relationship between
ends and scarce means which have alternative uses.

LIONEL CHARLES ROBBINS, LORD ROBBINS,
AN ESSAY ON THE NATURE AND SIGNIFICANCE OF ECONOMIC SCIENCE (1932)

THE ECONOMIC ANALYSIS of law draws upon the principles of microeconomic the-
ory, which we review in this chapter. For those who have not studied this branch
of economics, reading this chapter will prove challenging but useful for under-

standing the remainder of the book. For those who have already mastered microeco-
nomic theory, reading this chapter is unnecessary. For those readers who are
somewhere in between these extremes, we suggest that you begin reading this chapter,
skimming what is familiar and studying carefully what is unfamiliar. If you’re not sure
where you lie on this spectrum of knowledge, turn to the questions at the end of the
chapter. If you have difficulty answering them, you will benefit from studying this
chapter carefully.

I. Overview: The Structure of Microeconomic Theory
Microeconomics concerns decision making by individuals and small groups, such

as families, clubs, firms, and governmental agencies. As the famous quote from Lord
Robbins at the beginning of the chapter says, microeconomics is the study of how

11

2 A Brief Review of
Microeconomic Theory

12 C H A P T E R 2 A Brief Review of Microeconomic Theory

scarce resources are allocated among competing ends. Should you buy that digital au-
diotape player you’d like, or should you buy a dapper suit for your job interview?
Should you take a trip with some friends this weekend or study at home? Because you
have limited income and time and cannot, therefore, buy or do everything that you
might want to buy or do, you have to make choices. Microeconomic theory offers a
general theory about how people make such decisions.

We divide our study of microeconomics into five sections. The first is the theory of
consumer choice and demand. This theory describes how the typical consumer, con-
strained by a limited income, chooses among the many goods and services offered for
sale.

The second section deals with the choices made by business organizations or firms.
We shall develop a model of the firm that helps us to see how the firm decides what
goods and services to produce, how much to produce, and at what price to sell its out-
put. In the third section, we shall consider how consumers and firms interact. By com-
bining the theory of the consumer and the firm, we shall explain how the decisions of
consumers and firms are coordinated through movements in market price. Eventually,
the decisions of consumers and firms must be made consistent in the sense that some-
how the two sides agree about the quantity and price of the good or service that will be
produced and consumed. When these consumption and production decisions are con-
sistent in this sense, we say that the market is in equilibrium. We shall see that power-
ful forces propel markets toward equilibrium, so that attempts to divert the market from
its path are frequently ineffectual or harmful.

The fourth section of microeconomic theory describes the supply and demand for
inputs into the productive process. These inputs include labor, capital, land, and mana-
gerial talent; more generally, inputs are all the things that firms must acquire in order to
produce the goods and services that consumers or other firms wish to purchase.

The final section of microeconomics deals with the area known as welfare
economics. There we shall discuss the organization of markets and how they achieve
efficiency.

These topics constitute the core of our review of microeconomic theory. There are
four additional topics that do not fit neatly into the sections noted above but that we
think you should know about them in order to understand the economic analysis of
legal rules and institutions. These are game theory, the economic theory of decision
making under uncertainty, growth theory, and behavioral economics. We shall cover
these four topics in the final sections of this chapter.

II. Some Fundamental Concepts: Maximization,
Equilibrium, and Efficiency

Economists usually assume that each economic actor maximizes something:
Consumers maximize utility (that is, happiness or satisfaction), firms maximize profits,
politicians maximize votes, bureaucracies maximize revenues, charities maximize
social welfare, and so forth. Economists often say that models assuming maximizing
behavior work because most people are rational, and rationality requires maximization.

II. Some Fundamental Concepts: Maximization, Equilibrium, and Efficiency 13

One conception of rationality holds that a rational actor can rank alternatives according
to the extent that they give her what she wants. In practice, the alternatives available to
the actor are constrained. For example, a rational consumer can rank alternative bun-
dles of consumer goods, and the consumer’s budget constrains her choice among them.
A rational consumer should choose the best alternative that the constraints allow.
Another common way of understanding this conception of rational behavior is to rec-
ognize that consumers choose alternatives that are well suited to achieving their ends.

Choosing the best alternative that the constraints allow can be described mathe-
matically as maximizing. To see why, consider that the real numbers can be ranked
from small to large, just as the rational consumer ranks alternatives according to the
extent that they give her what she wants. Consequently, better alternatives can be asso-
ciated with larger numbers. Economists call this association a “utility function,” about
which we shall say more in the following sections. Furthermore, the constraint on
choice can usually be expressed mathematically as a “feasibility constraint.” Choosing
the best alternative that the constraints allow corresponds to maximizing the utility
function subject to the feasibility constraint. So, the consumer who goes shopping is
said to maximize utility subject to her budget constraint.

Turning to the second fundamental concept, there is no habit of thought so deeply
ingrained among economists as the urge to characterize each social phenomenon as an
equilibrium in the interaction of maximizing actors. An equilibrium is a pattern of in-
teraction that persists unless disturbed by outside forces. Economists usually assume
that interactions tend toward an equilibrium, regardless of whether they occur in mar-
kets, elections, clubs, games, teams, corporations, or marriages.

There is a vital connection between maximization and equilibrium in microeco-
nomic theory. We characterize the behavior of every individual or group as maximizing
something. Maximizing behavior tends to push these individuals and groups toward a
point of rest, an equilibrium. They certainly do not intend for an equilibrium to result;
instead, they simply try to maximize whatever it is that interests them. Nonetheless, the
interaction of maximizing agents usually results in an equilibrium.

A stable equilibrium is one that will not change unless outside forces intervene. To
illustrate, the snowpack in a mountain valley is in stable equilibrium, whereas the
snowpack on the mountain’s peak may be in unstable equilibrium. An interaction
headed toward a stable equilibrium actually reaches this destination unless outside
forces divert it. In social life, outside forces often intervene before an interaction
reaches equilibrium. Nevertheless, equilibrium analysis makes sense. Advanced micro-
economic theories of growth, cycles, and disequilibria exist, but we shall not need them
in this book. The comparison of equilibria, called comparative statics, will be our basic
approach.

Turning to the third fundamental concept, economists have several distinct defini-
tions of efficiency. A production process is said to be productively efficient if either of
two conditions holds:

1. It is not possible to produce the same amount of output using a lower-cost
combination of inputs, or

2. It is not possible to produce more output using the same combination of
inputs.

14 C H A P T E R 2 A Brief Review of Microeconomic Theory

Consider a firm that uses labor and machinery to produce a consumer good called
a “widget.” Suppose that the firm currently produces 100 widgets per week using
10 workers and 15 machines. The firm is productively efficient if

1. it is not possible to produce 100 widgets per week by using 10 workers and
fewer than 15 machines, or by using 15 machines and fewer than 10 work-
ers, or

2. it is not possible to produce more than 100 widgets per week from the com-
bination of 10 workers and 15 machines.

The other kind of efficiency, called Pareto efficiency after its inventor1 or sometimes
referred to as allocative efficiency, concerns the satisfaction of individual preferences. A
particular situation is said to be Pareto or allocatively efficient if it is impossible to
change it so as to make at least one person better off (in his own estimation) without
making another person worse off (again, in his own estimation). For simplicity’s sake,
assume that there are only two consumers, Smith and Jones, and two goods, umbrellas
and bread. Initially, the goods are distributed between them. Is the allocation Pareto effi-
cient? Yes, if it is impossible to reallocate the bread and umbrellas so as to make either
Smith or Jones better off without making the other person worse off.2

These three basic concepts—maximization, equilibrium, and efficiency—are fun-
damental to explaining economic behavior, especially in decentralized institutions like
markets that involve the coordinated interaction of many different people.

III. Mathematical Tools
You may have been anxious about the amount of mathematics that you will find in

this book. There is not much. We use simple algebra and graphs.

A. Functions
Economics is rife with functions: production functions, utility functions, cost func-

tions, social welfare functions, and others. A function is a relationship between two sets
of numbers such that for each number in one set, there corresponds exactly one number
in the other set. To illustrate, the columns below correspond to a functional relationship
between the numbers in the left-hand column and those in the right-hand column. Thus,
the number 4 in the x-column below corresponds to the number 10 in the y-column.

In fact, notice that each number in the x-column corresponds to exactly one number in
the y-column. Thus, we can say that the variable y is a function of the variable x, or in the
most common form of notation.

y = f(x).

1 Vilfredo Pareto was an Italian-Swiss political scientist, lawyer, and economist who wrote around 1900.
2 There is another efficiency concept—a potential Pareto improvement or Kaldor-Hicks efficiency—that we

describe in section IX.C that follows.

III. Mathematical Tools 15

Note that the number 4 is not the only number in the x-column that corresponds to
the number 10 in the y-column; the number 6 also corresponds to the number 10. In this
table, for a given value of x, there corresponds one value of y, but for some values of y,
there corresponds more than one value of x. A value of x determines an exact value of y,
whereas a value of y does not determine an exact value of x. Thus, in is
called the dependent variable, because it depends on the value of x, and x is called the
independent variable. Because y depends upon x in this table, y is a function of x, but
because x does not (to our knowledge) depend for its values on y, x is not a function of y.

Now suppose that there is another dependent variable, named z, that also depends
upon x. The function relating z to x might be named g:

When there are two functions, g(x) and f(x), with different dependent variables, z
and y, remembering which function goes with which variable can be hard. To avoid
this difficulty, the same name is often given to a function and the variable determined
by it. Following this strategy, the preceding functions would be renamed as follows:

Sometimes an abstract function will be discussed without ever specifying the exact
numbers that belong to it. For example, the reader might be told that y is a function of
x, and never be told exactly which values of y correspond to which values of x. The
point then is simply to make the general statement that y depends upon x but in an as
yet unspecified way. If exact numbers are given, they may be listed in a table, as we
have seen. Another way of showing the relationship between a dependent and an inde-
pendent variable is to give an exact equation. For example, a function might
be given the exact form

which states that the function z matches values of x with values of z equal to five plus
one-half of whatever value x takes. The table below gives the values of z associated
with several different values of x:

z = z(x) = 5 + x>2,

z = z(x)

z = g(x)Q z = z(x).

y = f(x)Q y = y(x),

z = g(x).

y = f(x), y

y-column x-column

2 3
3 0

10 4
10 6
12 9
7 12

This is read as “y is a function of x” or “y equals some f of x.”

16 C H A P T E R 2 A Brief Review of Microeconomic Theory

A function can relate a dependent variable (there is always just one of them to a
function) to more than one independent variable. If we write we are
saying that the function h matches one value of the dependent variable y to every
pair of values of the independent variables x and z. This function might have the
specific form

according to which y decreases by 3 units when x increases by 1 unit, and y increases
by 1 unit when z increases by 1 unit.

B. Graphs
We can improve the intuitive understanding of a functional relationship by visual-

izing it in a graph. In a graph, values of the independent variable are usually read off
the horizontal axis, and values of the dependent variable are usually read off the verti-
cal axis. Each point in the grid of lines corresponds to a pair of values for the variables.
For an example, see Figure 2.1. The upward-sloping line on the graph represents all of
the pairs of values that satisfy the function You can check this by find-
ing a couple of points that ought to be on the line that corresponds to that function. For
example, what if What value should x have? If then a little arithmetic
will reveal that x should equal Thus, the pair is a point on the line de-
fined by the function. What if What value will y have? In that case, the secondx = 0?

(0, -10)-10.
y = 0,y = 0?

y = 5 + x>2.

y = h(x, z) = -3x + z,

y = h(x, z),

y

x

–y

–x

15

10

0

5

5 10 15– 5

– 5

– 10

– 10– 15

y = 5 – x!2

y = 5 + x!2

FIGURE 2.1
Graphs of the linear relationships

(with a positive slope) and
(with a negative slope).y = 5 – x>2y = 5 + x>2

z-column x-column

6.5 3
12.5 15
8.0 6
6.0 2
9.5 9

III. Mathematical Tools 17

term in the right-hand side of the equation disappears, so that Thus, the pair of
values (5, 0) is a point on the line defined by the function.

The graph of reveals some things about the relationship between y
and x that we otherwise might not so easily discover. For example, notice that the line
representing the equation slopes upward, or from southwest to northeast. The positive
slope, as it is called, reveals that the relationship between x and y is a direct one. Thus,
as x increases, so does y. And as x decreases, y decreases. Put more generally, when the
independent and dependent variables move in the same direction, the slope of the graph
of their relationship will be positive.

The graph also reveals the strength of this direct relationship by showing whether
small changes in x lead to small or large changes in y. Notice that if x increases by 2
units, y increases by 1 unit. Another way of putting this is to say that in order to get a
10-unit increase in y, there must be a 20-unit increase in x.3

The opposite of a direct relationship is an inverse relationship. In that sort of rela-
tionship, the dependent and independent variables move in opposite directions. Thus, if
x and y are inversely related, an increase in x (the independent variable) will lead to a
decrease in y. Also, a decrease in x will lead to an increase in y. An example of an in-
verse relationship between an independent and a dependent variable is
The graph of this line is also shown in Figure 2.1. Note that the line is downward-
sloping; that is, the line runs from northwest to southeast.

QUESTION 2.1: Suppose that the equation were Show in a
graph like the one in Figure 2.1 what the graph of that equation would look
like. Is the relationship between x and y direct or inverse? Is the slope of the
new equation greater or less than the slope shown in Figure 2.1?

Now suppose that the equation were Show in a graph like the
one in Figure 2.1 what the graph of that equation would look like. Is the rela-
tionship between x and y direct or inverse? Is the slope of the new equation
positive or negative? Would the slope of the equation be steeper
or shallower than that of the one in

The graph of in Figure 2.1 also reveals that the relationship between
the variables is linear. This means that when we graph the values of the independent
and dependent variables, the resulting relationship is a straight line. One of the impli-
cations of linearity is that changes in the independent variable cause a constant rate of
change in the dependent variable. In terms of Figure 2.1, if we would like to know the
effect on y of doubling the amount of x, it doesn’t matter whether we investigate that
effect when x equals 2 or 3147. The effect on y of doubling the value of x is proportion-
ally the same, regardless of the value of x.

The alternative to a linear relationship is, of course, a nonlinear relationship. In
general, nonlinear relationships are trickier to deal with than are linear relationships.

y = 5 + x>2 y = 5 – x?
y = 5 – x>2

y = 5 – x.

y = 5 + x.

y = 5 – x>2.

y = 5 + x>2 y = 5.

3 The slope of the equation we have been dealing with in Figure 2.1 is which is the coefficient of x in the
equation. In fact, in any linear relationship the coefficient of the independent variable gives the slope of the
equation.

1
2,

18 C H A P T E R 2 A Brief Review of Microeconomic Theory

They frequently, although not always, are characterized by the independent variable be-
ing raised to a power by an exponent. Examples are and Figure 2.2
shows a graph of Another common nonlinear relationship in economics is
given by the example where A is a constant. A graph of that function is given
in Figure 2.3.

IV. The Theory of Consumer Choice and Demand
The economist’s general theory of how people make choices is referred to as the

theory of rational choice. In this section we show how that theory explains the con-
sumer’s choice of what goods and services to purchase and in what amounts.

A. Consumer Preference Orderings
The construction of the economic model of consumer choice begins with an ac-

count of the preferences of consumers. Consumers are assumed to know the things they
like and dislike and to be able to rank the available alternative combinations of goods
and services according to their ability to satisfy the consumer’s preferences. This in-
volves no more than ranking the alternatives as better than, worse than, or equally as
good as one another. Indeed, some economists believe that the conditions they impose
on the ordering or ranking of consumer preferences constitute what an economist
means by the term rational. What are those conditions? They are that a consumer’s
preference ordering or ranking be complete, transitive, and reflexive. For an ordering to
be complete simply means that the consumer be able to tell us how she ranks all the

A = xy,
y = x2.

y = 5>x1
2.y = x2

y

x– x
0

y = x2

FIGURE 2.2
The graph of a nonlinear relationship,
given by the equation y = x 2.

y

x0

A = xy

FIGURE 2.3
The graph of a nonlinear relationship,
A = xy.

IV. The Theory of Consumer Choice and Demand 19

possible combinations of goods and services. Suppose that A represents a bundle of
certain goods and services and B represents another bundle of the same goods and serv-
ices but in different amounts. Completeness requires that the consumer be able to tell
us that she prefers A to B, or that she prefers B to A, or that A and B are equally good
(that is, that the consumer is indifferent between having A and having B). The consumer
is not allowed to say, “I can’t compare them.”

Reflexivity is an arcane condition on consumer preferences. It means that any bun-
dle of goods, A, is at least as good as itself. That condition is so trivially true that it is
difficult to give a justification for its inclusion.

Transitivity means that the preference ordering obeys the following condition:
If bundle A is preferred to bundle B and bundle B is preferred to bundle C, then it
must be the case that A is preferred to C. This also applies to indifference: If the
consumer is indifferent between A and B and between B and C, then she is also in-
different between A and C. Transitivity precludes the circularity of individual pref-
erences. That is, transitivity means that it is impossible for A to be preferred to B,
B to be preferred to C, and C to be preferred to A. Most of us would probably feel
that someone who had circular preferences was extremely young or childish or
crazy.

QUESTION 2.2: Suppose that you have asked James whether he would like
a hamburger or a hot dog for lunch, and he said that he wanted a hot dog. Five
hours later you ask him what he would like for dinner, a hamburger or a hot
dog. James answers, “A hamburger.” Do James’s preferences for hot dogs ver-
sus hamburgers obey the conditions above? Why or why not?

It is important to remember that the preferences of the consumer are subjective.
Different people have different tastes, and these will be reflected in the fact that they
may have very different preference orderings over the same goods and services.
Economists leave to other disciplines, such as psychology and sociology, the study of
the source of these preferences. We take consumer tastes or preferences as given, or, as
economists say, as exogenous, which means that they are determined outside the eco-
nomic system.4

An important consequence of the subjectivity of individual preferences is that
economists have no accepted method for comparing the strength of people’s prefer-
ences. Suppose that Stan tells us that he prefers bundle A to bundle B, and Jill tells us
that she feels the same way: She also prefers A to B. Is there any way to tell who would
prefer having A more? In the abstract, the answer is, “No, there is not.” All we have
from each consumer is the order of preference, not the strength of those preferences.
Indeed, there is no metric by which to measure the strength of preferences, although
economists sometimes jokingly refer to the “utils” of satisfaction that a consumer is
enjoying. The inability to make interpersonal comparisons of well-being has some

4 Many people new to the study of microeconomics will find this assumption of the exogeneity of preferences
to be highly unrealistic. And there is some controversy about this assumption even within economics, some
economists contending that preferences are endogenous—that is, determined within the economic system by
such things as advertising. We cannot elaborate on this controversy here but are well aware of it.

20 C H A P T E R 2 A Brief Review of Microeconomic Theory

important implications for the design and implementation of public policy, as we shall
see in the section on welfare economics.

B. Utility Functions and Indifference Curves
Once a consumer describes what his or her preference ordering is, we may derive

a utility function for that consumer. The utility function identifies higher preferences
with larger numbers. Suppose that there are only two commodities or services, x and y,
available to a given consumer. If we let u stand for the consumer’s utility, then the func-
tion describes the utility that the consumer gets from different combina-
tions of x and y.

A very helpful way of visualizing the consumer’s utility function is by means of
a graph called an indifference map. An example is shown in Figure 2.4. There we
have drawn several indifference curves. Each curve represents all the combinations
of x and y that give the consumer the same amount of utility or well-being. Alternatively,
we might say that the consumer’s tastes are such that he is indifferent among all the
combinations of x and y that lie along a given curve—hence, the name indifference
curve. Thus, all those combinations of x and y lying along the indifference curve
marked give the consumer the same utility. Those combinations lying on the
higher indifference curve marked give this consumer similar utility, but this level
of utility is higher than that of all those combinations of x and y lying along indiffer-
ence curve

QUESTION 2.3: Begin at point Now decrease x from to How
much must y increase to offset the decrease in x and keep the consumer
indifferent?

The problem of consumer choice arises from the collision of the consumer’s pref-
erences with obstacles to his or her satisfaction. The obstacles are the constraints that
force decision makers to choose among alternatives. There are many constraints,
including time, energy, knowledge, and one’s culture, but foremost among these is

x1.x0(x0, y0).

U0.

U1

U0

u = u(x, y)

y

x0
U0

U1

U2
U3

x0x1

y0
(x0, y0)

FIGURE 2.4
The consumer’s indifference map.

IV. The Theory of Consumer Choice and Demand 21

y

x0

I = pxx + pyy

FIGURE 2.5
The consumer’s income constraint or
budget line.

limited income. We can represent the consumer’s income constraint or budget line by
the line in Figure 2.5. The area below the line and the line itself represent all the com-
binations of x and y that are affordable, given the consumer’s income, I.5 Presumably,
the consumer intends to spend all of her income on purchases of these two goods and
services, so that the combinations upon which we shall focus are those that are on the
budget line itself.

QUESTION 2.4: In a figure like the one in Figure 2.5 and beginning with a
budget line like the one in Figure 2.5, show how you would draw the new in-
come constraint to reflect the following changes?

1. An increase in the consumer’s income, prices held constant.
2. A decrease in the consumer’s income, prices held constant.
3. A decrease in the price of x, income and the price of y held constant.
4. An increase in the price of y, income and the price of x held constant.

C. The Consumer’s Optimum
We may now combine the information about the consumer’s tastes given by the

indifference map and the information about the income constraint given by the
budget line in order to show what combination of x and y maximizes the consumer’s
utility, subject to the constraint imposed by her income. See Figure 2.6. There the
consumer’s optimum bundle is shown as point M, which contains and Of all
the feasible combinations of x and y, that combination gives this consumer the great-
est utility.6

y*.x*

5 The equation for the budget line is where is the price per unit of x and is the price
per unit of y. As an exercise, you might try to rearrange this equation, with y as the dependent variable, in
order to show that the slope of the line is negative. When you do so, you will find that the coefficient of the
x-term is equal to Economists refer to this ratio as relative price.-px>py.

pypxI = pxx + pyy,

6 Because we have assumed that the normal indifference curves are convex to the origin, there is a unique
bundle of x and y that maximizes the consumer’s utility. For other shapes of the indifference curves it is
possible that there is more than one bundle that maximizes utility.

22 C H A P T E R 2 A Brief Review of Microeconomic Theory

D. A Generalization: The Economic Optimum
as Marginal Cost ! Marginal Benefit
Because of the central importance of constrained maximization in microeconomic

theory, let us take a moment to examine a more general way of characterizing such a
maximum:

A constrained maximum, or any other economic optimum, can be described as a point
where marginal cost equals marginal benefit.

Let’s see how this rule characterizes maximizing decisions.7 Begin by assuming
that the decision maker chooses some initial level of whatever it is he is interested in
maximizing. He then attempts to determine whether that initial level is his maximum;
is that level as good as he can do, given his constraints? He can answer the question by
making very small, what an economist calls marginal, changes away from that initial
level. Suppose that the decision maker proposes to increase slightly above his initial
level whatever it is he is doing. There will be a cost associated with this small increase
called marginal cost. But there will also be a benefit of having or doing more of what-
ever it is that he is attempting to maximize. The benefit of this small increase is called
marginal benefit. The decision maker will perceive himself as doing better at this new
level, by comparison to his initial level, so long as the marginal benefit of the small in-
crease is greater than the marginal cost of the change. He will continue to make these
small, or marginal, adjustments so long as the marginal benefit exceeds the marginal
cost, and he will stop making changes when the marginal cost of the last change made
equals (or is greater than) the marginal benefit. That level is the decision maker’s
maximum.

QUESTION 2.5: Suppose that, instead of increasing his level above the ini-
tial choice, the decision maker first tries decreasing the amount of whatever it
is he is attempting to maximize. Explain how the comparison of marginal cost

7 This rule could describe equally well an economic optimum where the goal of the decision maker is to minimize
something. In that case, the optimum would still be the point at which but the demonstration of
the stylized decision making that got one to that point would be different from that given in the text.

MC = MB,

y

y*

x*
x0

M

U = xy

FIGURE 2.6
The consumer’s optimum.

IV. The Theory of Consumer Choice and Demand 23

and marginal benefit for these decreases is made and leads the decision maker
to the optimum. (Assume that the initial level is greater than what will ulti-
mately prove to be the optimum.)

We can characterize the consumer’s income-constrained maximum, M in Figure
2.6, in terms of the equality of marginal cost and benefit. Small changes in either di-
rection along the budget line, I, represent a situation in which the consumer spends
a dollar less on one good and a dollar more on the other. To illustrate, assume the
consumer decides to spend a dollar less on y and a dollar more on x. Purchasing a
dollar less of y causes a loss in utility that we may call the marginal cost of the
budget reallocation. But the dollar previously spent on y can now be spent on x.
More units of x mean greater utility, so that we may call this increase the marginal
benefit of the budget reallocation.

Should the consumer spend a dollar less on good y and a dollar more on x? Only if
the marginal cost (the decrease in utility from one dollar less of y) is less than the mar-
ginal benefit (the increase in utility from having one dollar more of x). The rational
consumer will continue to reallocate dollars away from the purchase of y and toward
the purchase of x until the marginal benefit of the last change made equals the marginal
cost. This occurs at the point M in Figure 2.6.

Figure 2.7 applies constrained maximization to reduce the amount of pollution.
Along the vertical axis are dollar amounts. Along the horizontal axis are units of pollu-
tion reduction. At the origin there is no effort to reduce pollution. At the vertical line
labeled “100%,” pollution has been completely eliminated.

The curve labeled MB shows the marginal benefit to society of reducing pollution.
We assume that this has been correctly measured to take into account health, scenic,
and all other benefits that accrue to members of society from reducing pollution at var-
ious levels. This line starts off high and then declines. This downward slope captures
the fact that the very first efforts at pollution reduction confer large benefits on society.
The next effort at reducing pollution also confers a social benefit, but not quite as great
as the initial efforts. Finally, as we approach the vertical line labeled “100%” and all
vestiges of pollution are being eliminated, the benefit to society of achieving those last
steps is positive, but not nearly as great as the benefit of the early stages of pollution
reduction.

$

MC = MB

Reduction
in pollution

Marginal cost of
pollution reduction

MC

MB

Marginal benefit
of pollution reduction

0
100%P*

FIGURE 2.7
The socially optimal amount of
pollution-reduction effort.

24 C H A P T E R 2 A Brief Review of Microeconomic Theory

The curve labeled MC represents the “social” as opposed to “private” marginal
cost of achieving given levels of pollution reduction. The individuals and firms that pol-
lute must incur costs to reduce pollution: They may have to adopt cleaner and safer pro-
duction processes that are also more expensive; they may have to install monitoring
devices that check the levels of pollution they generate; and they may have to defend
themselves in court when they are accused of violating the pollution-reduction guide-
lines. We have drawn the MC curve to be upward-sloping to indicate that the marginal
costs of achieving any given level of pollution-reduction increase. This means that the
cost of reducing the very worst pollution may not be very high, but that successive
levels of reduction will be ever more expensive.

Given declining marginal benefit and rising marginal cost, the question then arises,
“What is the optimal amount of pollution-reduction effort for society?” An examina-
tion of Figure 2.7 shows that is the socially optimal amount of pollution-reduction
effort. Any more effort will cost more than it is worth. Any less would cause a reduc-
tion in benefits that would be greater than the savings in costs.

Note that, according to this particular graph, it would not be optimal for society to
try to eliminate pollution entirely. Here it is socially optimal to tolerate some pollution.
Specifically, when pollution reduction equals the remaining pollution equals

which is the “optimal amount of pollution.” Few goods are free. Much of
the wisdom of economics comes from the recognition of this fact and of the derivation
of techniques for computing the costs and benefits.

QUESTION 2.6: Suppose that we were to characterize society’s decision
making with regard to pollution-reduction efforts as an attempt to maximize
the net benefit of pollution-reduction efforts. Let us define net benefit as the
difference between marginal benefit and marginal cost. What level of pollution-
reduction effort corresponds to this goal?

QUESTION 2.7: Using a graph like Figure 2.7, show the effect on the deter-
mination of the socially optimal amount of pollution-reduction effort of the
following:

1. Some technological change that lowers the marginal cost of achieving every
level of pollution reduction.

2. A discovery that there are greater health risks associated with every given level
of pollution than were previously thought to be the case.

If you understand that for economists, the optimum for nearly all decisions occurs
at the point at which marginal benefit equals marginal cost, then you have gone a long
way toward mastering the microeconomic tools necessary to answer most questions
that we will raise in this book.

E. Individual Demand
We may use the model of consumer choice of the previous sections to derive a re-

lationship between the price of a good and the amount of that good in a consumer’s op-
timum bundle. The demand curve represents this relationship.

100% – P*,
P*,

P*

IV. The Theory of Consumer Choice and Demand 25

Starting from point M in Figure 2.6, note that when the price of x is that given by
the budget line, the optimal amount of x to consume is But what amount of x will
this consumer want to purchase so as to maximize utility when the price of x is lower
than that given by the budget line in Figure 2.6? We can answer that question by hold-
ing and I constant, letting fall, and writing down the amount of x in the succeed-
ing optimal bundles. Not surprisingly, the result of this exercise will be that the price of
x and the amount of x in the optimum bundles are inversely related. That is, when the
price of x goes up, and I held constant (or ceteris paribus, “all other things equal,”
as economists say), the amount of x that the consumer will purchase goes down, and
vice versa. This result is the famous law of demand.

We may graph this relationship between and the quantity of x demanded to
get the individual demand curve, D, shown in Figure 2.8. The demand curve we
have drawn in Figure 2.8 could have had a different slope than that shown; it might
have been either flatter or steeper. The steepness of the demand curve is related to
an important concept called the price elasticity of demand, or simply elasticity of
demand.8

This is an extremely useful concept: It measures how responsive consumer de-
mand is to changes in price. And there are some standard attributes of goods that in-
fluence how responsive demand is likely to be. For instance, if two goods are similar
in their use, then an increase in the price of the first good with no change in the price
of the second good causes consumers to buy significantly less of the first good.
Generalizing, the most important determinant of the price elasticity of demand for a

Px

Py

PxPy

x*.

8 The measure is frequently denoted by the letter e, and the ranges of elasticity are called inelastic
elastic and unitary elastic By convention, e, the price elasticity of demand, is a positive
(or absolute) number, even though the calculation we suggested will lead to a negative number. For an in-
elastically demanded good, the percentage change in price exceeds the percentage change in quantity
demanded. Thus, a good that has is one for which a 50 percent decline in price will cause a 25 percent
increase in the quantity demanded, or for which a 15 percent increase in price will cause a 7.5 percent de-
cline in quantity demanded. For an elastically demanded good, the percentage change in price is less than
the percentage change in quantity demanded. As a result, a good that has is one for which a 50 per-
cent decline in price will cause a 75 percent increase in quantity demanded, or for which a 20 percent in-
crease in price will cause a 30 percent decline in quantity demanded.

e = 1.5

e = 0.5

(e = 1).(e 7 1),
(e 6 1),

P1

P0

Px

x0 x1

x0

D

FIGURE 2.8
An individual’s demand curve, showing
the inverse relationship between price
and quantity demanded.

26 C H A P T E R 2 A Brief Review of Microeconomic Theory

good is the availability of substitutes. The more substitutes for the good, the greater
the elasticity of demand; the fewer the substitutes, the lower the elasticity.
Substitution is easier for narrowly defined goods and harder for broad categories. If
the price of cucumbers goes up, switching to peas or carrots is easy; if the price of
vegetables goes up, switching to meat is possible; but if the price of food goes up,
eating less is hard to do. So, we expect that demand is more elastic for cucumbers
than vegetables and more elastic for vegetables than food. Also, demand is more
elastic in the long run than the short run. To illustrate, if electricity prices rise rela-
tive to natural gas, consumers will increasingly switch to burning gas as they gradu-
ally replace furnaces and appliances. Economists often measure and remeasure the
price elasticities of demand for numerous goods and services to predict responses to
price changes.

V. The Theory of Supply
We now turn to a review of the other side of the market: the supply side. The key

institution in supplying goods and services for sale to consumers is the business firm. In
this section we shall see what goal the firm seeks and how it decides what to supply. In
the following section, we merge our models of supply and demand to see how the inde-
pendent maximizing activities of consumers and firms achieve a market equilibrium.

A. The Profit-Maximizing Firm
The firm is the institution in which output (products and services) is fabricated

from inputs (capital, labor, land, and so on). Just as we assume that consumers ration-
ally maximize utility subject to their income constraint, we assume that firms maximize
profits subject to the constraints imposed on them by consumer demand and the tech-
nology of production.

In microeconomics, profits are defined as the difference between total revenue and
the total costs of production. Total revenue for the firm equals the number of units of
output sold multiplied by the price of each unit. Total costs equal the costs of each of
the inputs times the number of units of input used, summed over all inputs. The profit-
maximizing firm produces that amount of output that leads to the greatest positive dif-
ference between the firm’s revenue and its costs. Microeconomic theory demonstrates
that the firm will maximize its profits if it produces that amount of output whose mar-
ginal cost equals its marginal revenue. (In fact, this is simply an application of the gen-
eral rule we discussed in section IV.D earlier: To achieve an optimum, equate marginal
cost and marginal benefit.)

These considerations suggest that when marginal revenue exceeds marginal cost,
the firm should expand production, and that when marginal cost exceeds marginal rev-
enue, it should reduce production. It follows that profits will be maximized for that out-
put for which marginal cost and marginal revenue are equal. Note the economy of this
rule: To maximize profits, the firm need not concern itself with its total costs or total
revenues; instead, it can simply experiment on production unit by unit in order to dis-
cover the output level that maximizes its profits.

V. The Theory of Supply 27

In Figure 2.9 the profit-maximizing output of the firm is shown at the point at
which the marginal cost curve, labeled MC, and marginal revenue curve of the firm are
equal. The profit-maximizing output level is denoted Total profits at this level of
production, denoted by the shaded area in the figure, equal the difference between the
total revenues of the firm ( p times ) and the total costs of the firm (the average cost
of producing times ).

There are several things you should note about the curves in the graph. We have
drawn the marginal revenue curve as horizontal and equal to the prevailing price. This
implies that the firm can sell as much as it likes at that prevailing price. Doubling its
sales will have no effect on the market price of the good or service. This sort of behav-
ior is referred to as price-taking behavior. It characterizes industries in which there are
so many firms, most of them small, that the actions of no single firm can affect the mar-
ket price of the good or service. An example might be farming. There are so many sup-
pliers of wheat that the decision of one farmer to double or triple output or cut it in half
will have no impact on its market price. (Of course, if all farms decide to double out-
put, there will be a substantial impact on market price.) Such an industry is said to be
“perfectly competitive.”

B. The Short Run and the Long Run
In microeconomics the firm is said to operate in two different time frames: the

short run and the long run. These time periods do not correspond to calendar time.
Instead they are defined in terms of the firm’s inputs. In the short run at least one input
is fixed (all others being variable), and the usual factor of production that is fixed is
capital (the firm’s buildings, machines, and other durable inputs). Because capital is
fixed in the short run, all the costs associated with capital are called fixed costs. In the
short run the firm can, in essence, ignore those costs: They will be incurred regardless
of whether the firm produces nothing at all or 10 million units of output. (The only
costs that change in the short run are “variable costs,” which rise or fall depending on
how much output the firm produces.) The long run is distinguished by the fact that all
factors of production become variable. There are no longer any fixed costs. Established
firms may expand their productive capacity or leave the industry entirely, and new
firms may enter the business.

q*q*
q*

q*.

AC ‘

p

Price

q*
q0

MC

AC

p = MR

FIGURE 2.9
The profit-maximizing output for
a firm.

28 C H A P T E R 2 A Brief Review of Microeconomic Theory

Another important distinction between the long and the short run has to do with
the equilibrium level of profits for each firm. At any point in time there is an average
rate of return earned by capital in the economy as a whole. When profits being earned
in a particular industry exceed the average profit rate for comparable investments, firms
will enter the industry, assuming there are no barriers to entry. As entry occurs, the to-
tal industry output increases, and the price of the industry output goes down, causing
each firm’s revenue to decrease. Also, the increased competition for the factors of pro-
duction causes input prices to rise, pushing up each firm’s costs. The combination of
these two forces causes each firm’s profits to decline. Entry ceases when profits fall to
the average rate.

Economists have a special way of describing these facts. The average return on
capital is treated as part of the costs that are subtracted from revenues to get “economic
profits.” Thus, when the rate of return on invested capital in this industry equals the
average for the economy as a whole, it is said that “economic profits are zero.”9

This leads to the conclusion that economic profits are zero in an industry that is in
long-run equilibrium. Because this condition can occur only at the minimum point of
the firm’s average cost curve, where the average costs of production are as low as they
can possibly be, inputs will be most efficiently used in long-run equilibrium. Thus, the
condition of zero economic profits, far from being a nightmare, is really a desirable
state.

VI. Market Equilibrium
Having described the behavior of utility-maximizing consumers and profit-

maximizing producers, our next task is to bring them together to explain how they
interact. We shall first demonstrate how a unique price and quantity are determined
by the interaction of supply and demand in a perfectly competitive market and then
show what happens to price and quantity when the market structure changes to one
of monopoly. We conclude this section with an example of equilibrium analysis of
an important public policy issue.

A. Equilibrium in a Perfectly Competitive Industry
An industry in which there are so many firms that no one of them can influence the

market price by its individual decisions and in which there are so many consumers that
the individual utility-maximizing decisions of no one consumer can affect the market
price is called a perfectly competitive industry. For such an industry the aggregate de-
mand for and the aggregate supply of output can be represented by the downward-sloping
demand curve, and the upward-sloping supply curve, showns = s(p),d = d(p),

9 When profits in a given industry are less than the average in the economy as a whole, economic profits are
said to be negative. When that is the case, firms exit this industry for other industries where the profits are
at least equal to the average for the economy. As an exercise, see if you can demonstrate the process by
which profits go to zero when negative economic profits in an industry cause exit to take place.

VI. Market Equilibrium 29

in Figure 2.10. The market-clearing or equilibrium price and quantity occur at the point
of intersection of the aggregate supply and demand curves. At that combination of price
and quantity, the decisions of consumers and suppliers are consistent.

One way to see why the combination in Figure 2.10 is an equilibrium is to
see what would happen if a different price-quantity combination were obtained.
Suppose that the initial market price was At that price, producers would maximize
their profits by supplying of output, and utility-maximizing consumers would be
prepared to purchase units of output. These supply and demand decisions are in-
consistent: At the amount that suppliers would like to sell exceeds the amount that
consumers would like to buy. How will the market deal with this excess supply?
Clearly, the market price must fall. As the price falls, consumers will demand more and
producers will supply less, so the gap between supply and demand will diminish.
Eventually the price may reach And at that price, as we have seen, the amount that
suppliers wish to sell and the amount that consumers wish to purchase are equal.

B. Equilibrium in a Monopolistic Market
Monopoly is at the other extreme of market structure. In a monopoly there is only

one supplier; so, that firm and the industry are identical. A monopoly can arise and per-
sist only where there are barriers to entry that make it impossible for competing firms
to appear. In general, such barriers can arise from two sources: first, from statutory and
other legal restrictions on entry; and second, from technological conditions of produc-
tion known as economies of scale. An example of a statutory restriction on entry was
the Civil Aeronautics Board’s refusal from the 1930s until the mid-1970s to permit
entry of new airlines into the market for passenger traffic on such major routes as Los
Angeles–New York and Chicago–Miami.

The second barrier to entry is technological. Economies of scale are a condition of
production in which the greater the level of output, the lower the average cost of pro-
duction. Where such conditions exist, one firm can produce any level of output at less
cost than multiple firms. A monopolist that owes its existence to economies of scale is
sometimes called a natural monopoly. Public utilities, such as local water, telecommu-
nications, cable, and power companies, are often natural monopolies. The technological
advantages of a natural monopoly would be partially lost if the single firm is allowed

Pc.

P1,
qd1

qs1

P1.

Pc, qc

Price

Quantity

s = s(p)

d = d(p)

0
qd1 qc qs1

Pc

P1

excess supply

FIGURE 2.10
Market equilibrium in a perfectly
competitive market.

30 C H A P T E R 2 A Brief Review of Microeconomic Theory

to restrict its output and to charge a monopoly price. For that reason, natural monopo-
lies are typically regulated by the government.

The monopolist, like the competitive firm, maximizes profit by producing that out-
put for which marginal cost equals marginal revenue. Marginal cost of the monopolist,
as for the competitive firm, is the cost of producing one more unit of output. This cost
curve is represented in Figure 2.11 by the curve labeled MC. But marginal revenue for
the monopolist is different from what it was for the competitive firm. Recall that mar-
ginal revenue describes the change in a firm’s total revenues for a small, or marginal,

Opportunity Cost and Comparative Advantage

We have been implicitly using one of the most fundamental concepts in microeconomics:
opportunity cost. This term refers to the economic cost of an alternative that has been fore-
gone. When you decided to attend a college, graduate school, or law school, you gave up
certain other valuable alternatives, such as taking a job, training for the Olympics, or traveling
around the world on a tramp steamer. In reckoning the cost of going to college, graduate
school, or law school, the true economic cost was that of the next best alternative. This point
is true of the decisions of all economic actors: When maximizing utility, the consumer must
consider the opportunities given up by choosing one bundle of consumer goods rather than
another; when maximizing profits, the firm must consider the opportunities foregone by com-
mitting its resources to the production of widgets rather than to something else.

In general, the economic notion of opportunity cost is more expansive than the more
common notion of accounting cost. An example will make this point.10 Suppose that a rich
relative gives you a car whose market value is $15,000. She says that if you sell the car, you
may keep the proceeds, but that if you use the car yourself, she’ll pay for the gas, oil, mainte-
nance, repairs, and insurance. In short she says, “The use of the car is FREE!” But is it?
Suppose that the $15,000 for which the car could be sold would earn 12 percent interest per
year in a savings account, giving $1800 per year in interest income. If you use the car for 1
year, its resale value will fall to $11,000—a cost to you of $4000. Therefore, the opportunity
cost to you of using the car for 1 year is $4000 plus the foregone interest of $1800—a total
of $5800. This is far from being free. The accounting cost of using the car is zero, but the op-
portunity cost is positive.

Comparative advantage is another useful economic concept related to the notion of op-
portunity cost. The law of comparative advantage asserts that people should engage in those
pursuits where their opportunity costs are lower than others. For example, someone who is
7 feet tall has a comparative advantage in pursuing a career in professional basketball. But
what about someone whose skills are such that she can do many things well? Suppose, for
example, that a skilled attorney is also an extremely skilled typist. Should she do her own
typing or hire someone else to do it while she specializes in the practice of law? The notion of
comparative advantage argues for specialization: The attorney can make so much more
money by specializing in the practice of law than by trying to do both jobs that she could
easily afford to hire someone else who is less efficient at typing to do her typing for her.

10 The example is taken from ROY RUFFIN & PAUL GREGORY, PRINCIPLES OF MICROECONOMICS 156
(2d ed. 1986).

VI. Market Equilibrium 31

change in the number of units of output sold. For the competitive firm marginal rev-
enue is equal to the price of output. Because the competitive firm can sell as much as it
likes at the prevailing price, each additional unit of output sold adds exactly the sale
price to the firm’s total revenues. But for the monopolist, marginal revenue declines as
the number of units sold increases. This is indicated in Figure 2.11 by the downward-
sloping curve labeled MR. Notice that the MR curve lies below the demand curve. This
indicates that the marginal revenue from any unit sold by a monopolist is always less
than the price. MR is positive but declining for units of output between 0 and thus,
the sale of each of those units increases the firm’s total revenues but at a decreasing
rate. The unit actually adds nothing to the firm’s total revenues and for
each unit of output beyond MR is less than zero, which means that each of those
units actually reduces the monopolist’s total revenues.

The reason for this complex relationship between marginal revenue and units sold
by the monopolist is the downward-sloping demand curve. The downward-sloping de-
mand curve implies that the monopolist must lower the price to sell more units; but in
order to sell an additional unit of output he or she must lower the price not just on the
last or marginal unit but on all the units sold.11 From this fact it can be shown, using
calculus, that the addition to total revenues from an additional unit of output sold will
always be less than the price charged for that unit. Thus, because MR is always less
than the price for all units of output and because price declines along the demand curve,
the MR curve must also be downward sloping and lie below the demand curve.

The monopolist maximizes his profit by choosing that output level for which mar-
ginal revenue and marginal cost are equal. This output level, is shown in Figure
2.11. The demand curve indicates that consumers are willing to pay for that amount
of output. Notice that if this industry were competitive instead of monopolized, the
profit-maximizing actions of the firms would have resulted in an equilibrium price and
quantity at the intersection of the aggregate supply curve, S, and the industry demand
curve, D. The competitive price, is lower than the monopolistic price, and thePc,

Pm

qm,

qc,
(MR = 0),q0

qc;

Price

Quantity

d = d(p)

0
qm qc

Pc

Pm

MR

MC

FIGURE 2.11
Profit-maximizing output and price for
a monopolist.

11 This assumes that the monopolist cannot price-discriminate (that is, charge different prices to different
consumers for the same product).

32 C H A P T E R 2 A Brief Review of Microeconomic Theory

quantity of output produced and consumed under competition, is greater than under
monopoly.

Economists distinguish additional market structures that are intermediate between
the extremes of perfect competition and monopoly. The most important among these
are oligopoly and imperfect competition. An oligopolistic market is one containing a
few firms that recognize that their individual profit-maximizing decisions are interde-
pendent. That means that what is optimal for firm A depends not only on its marginal
costs and the demand for its output but also on what firms B, C, and D have decided to
produce and the prices they are charging. The economic analysis of this interdepen-
dence requires a knowledge of game theory, which we discuss below.

An imperfectly competitive market is one that shares most of the characteristics of
a perfectly competitive market—for example, free entry and exit of firms and the pres-
ence of many firms—but has one important monopolistic element: Firms produce
differentiable output rather than the homogeneous output produced by perfectly com-
petitive firms. Thus, imperfectly competitive firms distinguish their output by brand
names, colors, sizes, quality, durability, and so on.

C. An Example of Equilibrium Analysis
It is useful to have an example applying this theory to a real problem. Let us imag-

ine a market for rental housing like the one shown in Figure 2.12. The demand for
rental housing is given by the curve D, and the supply of rental housing is given by the
upward-sloping supply curve S. Assuming that the rental housing market is competi-
tive, then the independent actions of consumers and of profit-maximizing housing own-
ers will lead to a rental rate of being charged and of units of rental housing being
supplied and demanded. Note that this is an equilibrium in the sense we discussed
above: The decisions of those demanding the product and of those supplying it are con-
sistent at the price Unless something causes the demand curve or the supply curve to
shift, this price and output combination will remain in force.

But now suppose that the city government feels that is too high and passes an
ordinance that specifies a maximum rental rate for housing of considerably belowrm,

r1

r1.

h1r1

qc,

Rental
rate

Housing0
hs h1 hd

r1

rm

r2

S

D

excess demand

FIGURE 2.12
The consequences of a rent-control
ordinance that prescribes rents below
the market-clearing rental rate.

VII. Game Theory 33

the equilibrium market rate. The hope of the government is that at least the same
amount of housing will be consumed by renters but at a lower rental rate. A look at
Figure 2.12, however, leads one to doubt that result. At consumers demand units
of rental housing, an increase over the quantity demanded at the higher rate, But at
this lower rate suppliers are only prepared to supply units of rental housing.
Apparently it does not pay them to devote as much of their housing units to renters at
that lower rate; perhaps if is all one can get from renting housing units, suppliers
prefer to switch some of their units to other uses, such as occupancy by the owner’s
family or their sale as condominiums. The result of the rate ceiling imposed by the gov-
ernment is a shortage of, or excess demand for, rental units equal to

If the rate ceiling is strictly enforced, the shortage will persist. Some non-price
methods of determining who gets the units of rental housing must be found, such as
queuing. Eventually, the shortage may be eased if either the demand curve shifts inward
or the supply curve shifts outward. It is also possible that landlords will let their prop-
erty deteriorate by withholding routine maintenance and repairs, so that the quality of
their property falls to such an extent that provides a competitive rate of return to them.

If, however, the rate ceiling is not strictly enforced, then consumers and suppliers
will find a way to erase the shortage. For example, renters could offer free services or
secret payments (sometimes called side payments) to landlords in order to get the ef-
fective rental rate above and induce the landlord to rent to them rather than to those
willing to pay only Those services and side payments could amount to
per housing unit.

VII. Game Theory
The law frequently confronts situations in which there are few decision makers and

in which the optimal action for one person to take depends on what another actor chooses.
These situations are like games in that people must decide upon a strategy. A strategy is a
plan for acting that responds to the reactions of others. Game theory deals with any situa-
tion in which strategy is important. Game theory will, consequently, enhance our under-
standing of some legal rules and institutions. For those who would like to pursue this
topic in more detail, there are now several excellent introductory books on game theory.12

To characterize a game, we must specify three things:

1. players,
2. strategies of each player, and
3. payoffs to each player for each strategy.

(r2 – rm)rm.
rm

rm

hs

(hd – hs).

rm

hs

r1.
hdrm,

12 For those who would like to pursue game theory in more detail, there are now several excellent introduc-
tory texts: ERIC RASMUSEN, GAMES AND INFORMATION: AN INTRODUCTION TO GAME THEORY (3d ed. 2001);
DAVID KREPS, GAME THEORY AND ECONOMIC MODELING (1990); and AVINASH DIXIT & BARRY NALEBUFF,
THINKING STRATEGICALLY: THE COMPETITIVE EDGE IN BUSINESS, POLITICS, AND EVERYDAY LIFE (1991).
More advanced treatments may be found in ROGER MYERSON, GAME THEORY (1991) and DREW

FUDENBERG & JEAN TIROLE, GAME THEORY (1991). With special reference to law, see DOUGLAS BAIRD,
ROBERT GERTNER, & RANDAL PICKER, GAME THEORY AND THE LAW (1995).

34 C H A P T E R 2 A Brief Review of Microeconomic Theory

Let’s consider a famous example—the prisoner’s dilemma. Two people, Suspect 1
and Suspect 2, conspire to commit a crime. They are apprehended by the police outside
the place where the crime was committed, taken to the police station, and placed in sep-
arate rooms so that they cannot communicate. The authorities question them individu-
ally and try to play one suspect against the other. The evidence against them is
circumstantial—they were simply in the wrong place at the wrong time. If the prosecu-
tor must go to trial with only this evidence, then the suspects will have to be charged
with a minor offense and given a relatively light punishment—say, 1 year in prison. The
prosecutor would very much prefer that one or both of the suspects confesses to the
more serious crime that they are thought to have committed. Specifically, if either suspect
confesses (and thereby implicates the other) and the other does not, the non-confessor
will receive 7 years in prison, and as a reward for assisting the state, the confessor will
only receive six months in jail. If both suspects can be induced to confess, each will
spend 5 years in prison. What should each suspect do—confess or keep quiet?

The strategies available to the suspects can be shown in a payoff matrix like that in
Figure 2.13. Each suspect has two strategies: confess or keep quiet. The payoffs to each
player from following a given strategy are shown by the entries in the four cells of the
box, with the payoff to Suspect 2 given in the lower left-hand corner of each cell and
the payoff to Suspect 1 given in the upper right-hand corner of the cell.

Here is how to read the entries in the payoff matrix. If Suspect 1 confesses and
Suspect 2 also confesses, each will receive 5 years in prison. If Suspect 1 confesses and
Suspect 2 keeps quiet, Suspect 1 will spend six months in jail, and Suspect 2 will spend
7 years in prison. If Suspect 1 keeps quiet and Suspect 2 confesses, then Suspect 2 will
spend six months in jail, and Suspect 1 will spend 7 years in prison. Finally, if both sus-
pects keep quiet, each will spend 1 year in prison.

There is another way to look at Suspect 1’s options. The payoff matrix is sometimes
referred to as the strategic form of the game. An alternative is the extensive form. This
puts one player’s options in the form of a decision tree, which is shown in Figure 2.14.

We now wish to explore what the optimal strategy—confess or keep quiet—is for
each player, given the options in the payoff matrix and given some choice made by the
other player. Let’s consider how Suspect 1 will select her optimal strategy. Remember

Suspect 1

Suspect 2

Confess Keep quiet

Keep quiet

Confess

–5

–0.5

–7

–1
–5

–7 –1

–0.5

FIGURE 2.13
The strategic form of a game, also
known as a payoff matrix.

VII. Game Theory 35

that the players are being kept in separate rooms and cannot communicate with one
another. (Because the game is symmetrical, this is exactly the same way in which
Suspect 2 will select his optimal strategy.)

First, what should Suspect 1 do if Suspect 2 confesses? If she keeps quiet when
Suspect 2 confesses, she will spend 7 years in prison. If she confesses when Suspect 2
confesses, she will spend 5 years. So, if Suspect 2 confesses, clearly the best thing for
Suspect 1 to do is to confess.

But what if Suspect 2 adopts the alternative strategy of keeping quiet? What is the
best thing for Suspect 1 to do then? If Suspect 2 keeps quiet and Suspect 1 confesses,
she will spend only half a year in prison. If she keeps quiet when Suspect 2 keeps quiet,
she will spend 1 year in prison. Again, the best thing for Suspect 1 to do if the other
suspect keeps quiet is to confess.

Thus, Suspect 1 will always confess. Regardless of what the other player does,
confessing will always mean less time in prison for her. In the jargon of game theory
this means that confessing is a dominant strategy—the optimal move for a player to
make is the same, regardless of what the other player does.

Because the other suspect will go through precisely the same calculations, he will
also confess. Confessing is the dominant strategy for each player. The result is that the
suspects are both going to confess, and, therefore, each will spend 5 years in prison.

The solution to this game, that both suspects confess, is an equilibrium: There is
no reason for either player to change his or her strategy. There is a famous concept in
game theory that characterizes this equilibrium—a Nash equilibrium. In such an equi-
librium, no individual player can do any better by changing his or her behavior so long
as the other players do not change theirs. (Notice that the competitive equilibrium that
we discussed in previous sections is an example of a Nash equilibrium when there are
many players in the game.)

The notion of a Nash equilibrium is fundamental in game theory, but it has short-
comings. For instance, some games have no Nash equilibrium. Some games have sev-
eral Nash equilibria. And finally, there is not necessarily a correspondence between the

Suspect 1

Suspect 2

Suspect 1’s payoff

Suspect 2

confesses

keeps quiet

keeps quiet

keeps quiet

confesses

confesses

–5

–7

–1

–0.5

FIGURE 2.14
The extensive form of the prisoner’s
dilemma.

36 C H A P T E R 2 A Brief Review of Microeconomic Theory

Nash equilibrium and Pareto efficiency, the criterion that economists use to evaluate
many equilibria. To see why, return to the prisoner’s dilemma above. We have seen that
it is a Nash equilibrium for both suspects to confess. But you should note that this is
not a Pareto-efficient solution to the game from the viewpoint of the accused. When
both suspects confess, they will each spend 5 years in prison. It is possible for both
players to be better off. That would happen if they would both keep quiet. Thus, cell 4
(where each receives a year in prison) is a Pareto-efficient outcome. Clearly, that solu-
tion is impossible because the suspects cannot make binding commitments not to con-
fess.13

We may use the prisoner’s dilemma to discuss another important fundamental con-
cept of game theory—repeated games. Suppose that the prisoner’s dilemma were to be
played not just once but a number of times by the same players. Would that change our
analysis of the game? If the same players play the same game according to the same
rules repeatedly, then it is possible that cooperation can arise and that players have an
incentive to establish a reputation—in this case, for trustworthiness.

An important thing to know about a repeated game is whether the game will be re-
peated a fixed number of times or an indefinite number. To see the difference, suppose
that the prisoner’s dilemma above is to be repeated exactly ten times. Each player’s op-
timal strategy must now be considered across games, not just for one game at a time.
Imagine Suspect 2 thinking through, before the first game is played, what strategy he
ought to follow for each game. He might imagine that he and his partner, if caught after
each crime, will learn (or agree) to keep quiet rather than to confess. But then Suspect
2 thinks forward to the final game, the tenth. Even if the players had learned (or agreed)
to keep quiet through Game 9, things will be different in Game 10. Because this is the
last time the game is to be played, Suspect 1 has a strong incentive to confess. If she
confesses on the last game and Suspect 2 sticks to the agreement not to confess, he will
spend 7 years in prison to her half year. Knowing that she has this incentive to cheat on
an agreement not to confess in the last game, the best strategy for Suspect 2 is also to
confess in the final game. But now Game 9 becomes, in a sense, the final game. And in
deciding on the optimal strategy for that game, exactly the same logic applies as it did
for Game 10—both players will confess in Game 9, too. Suspect 1 can work all this out,
too, and she will realize that the best thing to do is to confess in Game 8, and so on. In
the terminology of game theory, the game unravels so that confession takes place by
each player every time the game is played, if it is to be played a fixed number of times.

Things may be different if the game is to be repeated an indefinite number of
times. In those circumstances there may be an inducement to cooperation. Robert
Axelrod has shown that in a game like the prisoner’s dilemma repeated an indefinite
number of times, the optimal strategy is tit-for-tat—if the other player cooperated on
the last play, you cooperate on this play; if she didn’t cooperate on the last play, you
don’t on this play.14

13 Can you think of a workable way in which the suspects might have agreed never to confess before they
perpetrated the crime? Put in the language of game theory, can a participant in a game like the prisoner’s
dilemma make a credible commitment not to confess if she and her partner are caught?

14 See ROBERT AXELROD, THE EVOLUTION OF COOPERATION (1984).

IX. General Equilibrium and Welfare Economics 37

These considerations of a fixed versus an indefinite number of plays of a game
may seem removed from the concerns of the law, but they really are not. Consider, for
example, the relations between a creditor and a debtor. When the debtor’s affairs are
going well, the credit relations between the creditor and the debtor may be analogized
to a game played an indefinite number of times. But if the debtor is likely to become
insolvent soon, the relations between debtor and creditor become much more like a
game to be played a fixed (and, perhaps, few) number of times. As a result, trust and
cooperation between the parties may break down, with the debtor trying to hide his as-
sets and the creditor trying to grab them for resale to recoup his losses.

We shall see that these concepts from game theory will play an important role in
our understanding of legal rules and institutions.

VIII. The Theory of Asset Pricing
The area of microeconomic theory that deals with capital and labor markets is be-

yond the scope of the material in this book. There is, however, one tool from this area
that we shall use: the theory of asset pricing.

Assets are resources that generate a stream of income. For instance, an apartment
building can generate a stream of rental payments; a patent can generate a stream of
royalty payments; an annuity can generate a fixed amount of income per year. There is
a technique for converting these various streams of future income (or future expenses
or, still more generally, net receipts) into a lump sum today. The general question that
is being asked is, “How much would you be prepared to pay today for an asset that gen-
erated a given future flow of net receipts in the future?”

We can answer that question by computing what is called the present discounted
value of the future flow of net receipts. Suppose that ownership of a particular asset
will generate in net receipts at the end of the first year; in net receipts at the end
of the second year; in net receipts at the end of the third year; and at the end of
the nth year. The present discounted value of that asset, supposing that the prevailing
rate of interest is r, is equal to:

This result has many applications to law. For instance, suppose that a court is seek-
ing to compensate someone whose property was destroyed. One method of valuing the
loss is to compute the present discounted value of the future flow of net receipts to
which the owner was entitled.

IX. General Equilibrium and Welfare Economics
The microeconomic theory we have been reviewing to this point has focused on

the fundamental concepts of maximization, equilibrium, and efficiency in describing
the decisions of consumers and firms. The part of microeconomic theory called welfare
economics explores how the decisions of many individuals and firms interact to affect

PDV =
F1

(1 + r)
+

F2

(1 + r)2 +
F3

(1 + r)3 + # # # +
Fn

(1 + r)n .

FnF3

F2F1

38 C H A P T E R 2 A Brief Review of Microeconomic Theory

the well-being of individuals as a group. Welfare economics is much more philosophi-
cal than other topics in microeconomic theory. Here the great policy issues are raised.
For example, is there an inherent conflict between efficiency and fairness? To what ex-
tent can unregulated markets maximize individual well-being? When and how should
the government intervene in the marketplace? Can economics identify a just distribu-
tion of goods and services? In this brief introduction, we can only hint at how micro-
economic theory approaches these questions. Nonetheless, this material is fundamental
to the economic analysis of legal rules.

A. General Equilibrium and Efficiency Theorems
One of the great accomplishments of modern microeconomics is the specification

of the conditions under which the independent decisions of utility-maximizing con-
sumers and profit-maximizing firms will lead to the inevitable, spontaneous establish-
ment of equilibrium in all markets simultaneously. Such a condition is known as
general equilibrium. General equilibrium will be achieved only when competitive
forces have led to the equality of marginal benefit and marginal cost in the market for
every single commodity and service. As you can well imagine, this condition is un-
likely to be realized in the real world. However, there are two practical reasons for
knowing what conditions must hold for general equilibrium to obtain. First, while all
real-world markets may not obey those conditions, many of them will. Second, the
specification of the conditions that lead to general equilibrium provides a benchmark
for evaluating various markets and making recommendations for public policy.

Modern microeconomics has demonstrated that general equilibrium has character-
istics that economists describe as socially optimal—that is, the general equilibrium is
both productively and allocatively efficient.

B. Market Failure
General equilibrium is, in welfare terms, such a desirable outcome that it would be

helpful to know the conditions under which it will hold. Stripped of detail, the essential
condition is that all markets are perfectly competitive. We can characterize the things
that can go wrong to prevent this essential condition from being attained in a market.
In this section we shall describe the four sources of market failure, as it is called, and
describe the public policies that can, in theory, correct those failures.

1. Monopoly and Market Power The first source of market failure is monop-
oly in its various forms: monopoly in the output market, collusion among otherwise
competitive firms or suppliers of inputs, and monopsony (only one buyer) in the input
market. If the industry were competitive, marginal benefit and marginal cost would be
equal. But as illustrated in Figure 2.11, the monopolist’s profit-maximizing output and
price combination occurs at a point where the price exceeds the marginal cost of pro-
duction. The price is too high, and the quantity supplied is too low from the viewpoint
of efficiency.

The public policies for correcting the shortcomings of monopoly are to replace
monopoly with competition where possible, or to regulate the price charged by the

IX. General Equilibrium and Welfare Economics 39

monopolist. The first policy is the rationale for the antitrust laws. But sometimes it is
not possible or even desirable to replace a monopoly. Natural monopolies, such as pub-
lic utilities, are an example; those monopolies are allowed to continue in existence, but
government regulates their prices.

2. Externalities The second source of market failure is the presence of what econ-
omists call externalities. Exchange inside a market is voluntary and mutually benefi-
cial. Typically, the parties to the exchange capture all the benefits and bear all the costs,
thus having the best information about the desirability of the exchange. But sometimes
the benefits of an exchange may spill over onto other parties than those explicitly en-
gaged in the exchange. Moreover, the costs of the exchange may also spill over onto
other parties. The first instance is an example of an external benefit; the second, an
external cost. An example of an external benefit is the pollination that a beekeeper pro-
vides to his neighbor who runs an apple orchard. An example of an external cost is air
or water pollution.

Let’s explore the idea of an external cost (frequently called simply an externality)
to see how it can lead to market failure and what public policies can correct this failing.
Suppose that a factory located upstream from a populous city dumps toxic materials
into the river as a by-product of its production process. This action by the factory im-
poses an unbargained-for cost on the townspeople downstream: They must incur some
additional costs to clean up the water or to bring in safe water from elsewhere. In what
way has the market failed in this example? The reason the market fails in the presence
of external costs is that the generator of the externality does not have to pay for harm-
ing others, and so exercises too little self-restraint. He or she acts as if the cost of dis-
posing of waste is zero, when, in fact, there are real costs involved, as the people
downstream can testify. In a technical sense, the externality generator produces too
much output and too much harm because there is a difference between private marginal
cost and social marginal cost.

Private marginal cost, in our example, is the marginal cost of production for the
factory. Social marginal cost is the sum of private marginal cost and the additional mar-
ginal costs involuntarily imposed on third parties by each unit of production. The dif-
ference is shown in Figure 2.15. Social marginal cost is greater than private marginal
cost at every level of output. The vertical difference between the two curves equals the

0 qs qp

Pc

$

q

SMC

PMC

$t

FIGURE 2.15
The difference between private and
social marginal cost.

40 C H A P T E R 2 A Brief Review of Microeconomic Theory

amount of the external marginal cost at any level of output. Note that if production is
zero, there is no externality, but that as production increases, the amount of external
cost per unit of output increases.

The profit-maximizing firm operates along its private marginal cost curve and
maximizes profits by choosing that output level for which —namely,
But from society’s point of view, this output is too large. Society’s resources will be
most efficiently used if the firm chooses its output level by equating and SMC at
At that level the firm has taken into account not only its own costs of production but
also any costs it imposes on others involuntarily.

What public policies will induce the externality generator to take external costs
into account? That is one of the central questions that this book will seek to answer.
The key to achieving the social optimum where there are externalities is to induce pri-
vate profit-maximizers to restrict their output to the socially optimal, not privately opti-
mal, point. This is done by policies that cause the firm to operate along the social
marginal cost curve rather than along the private marginal cost curve. When this is ac-
complished, the externality is said to have been internalized in the sense that the pri-
vate firm now takes it into consideration.

QUESTION 2.8: In Figure 2.15, if the firm is producing output, is there any
external cost being generated? If so, why is this output level called a social op-
timum? Would it not be optimal to have no external cost? At what level of out-
put would that occur? Does our earlier discussion that characterized any social
optimum as the point at which (social) marginal cost equals (social) marginal
benefit provide any guidance? Is the point at which social marginal cost and
social marginal benefit are equal consistent with the existence of some exter-
nal cost? Why or why not?

3. Public Goods The third source of market failure is the presence of a commod-
ity called a public good. A public good is a commodity with two very closely related
characteristics:

1. Nonrivalrous consumption: consumption of a public good by one person
does not leave less for any other consumer.

2. Nonexcludability: the costs of excluding nonpaying beneficiaries who con-
sume the good are so high that no private profit-maximizing firm is willing
to supply the good.

Consider national defense. Suppose, for the purposes of illustration, that national
defense were provided by competing private companies. For an annual fee a company
would sell protection to its customers against loss from foreign invasion by air, land, or
sea. Only those customers who purchase some company’s services would be protected
against foreign invasion. Perhaps these customers could be identified by special gar-
ments, and their property denoted by a large white X painted on the roof of their homes.

Who will purchase the services of these private national defense companies? Some
will but many will not. Many of the nonpurchasers will reason that if their neighbor will
purchase a protection policy from a private national defense company, then they, too,

qs.Pc

qp.Pc = PMC

IX. General Equilibrium and Welfare Economics 41

will be protected: It will prove virtually impossible for the private company to protect
the property and person of the neighbor without also providing security to the nearby
nonpurchaser. Thus, the consumption of national defense is nonrivalrous: Consumption
by one person does not leave less for any other consumer. For that reason, there is a
strong inducement for consumers of the privately provided public good to try to be free
riders: They hope to benefit at no cost to themselves from the payment of others.

The related problem for the private supplier of a public good is the difficulty of ex-
cluding nonpaying beneficiaries. The attempt to distinguish those who have from those
who have not subscribed to the private defense companies is almost certain to fail; for
example, the identifying clothes and property markings can easily be counterfeited.

As a result of the presence of free riders and the high cost of distinguishing non-
paying from paying beneficiaries, it is not likely that the private company will be able
to induce many people to purchase defense services. If private profit-maximizing firms
are the only providers of national defense, too little of that good will be provided.

How can public policy correct the market failure in the provision of public goods?
There are two general correctives. First, the government may undertake to subsidize the
private provision of the public good, either directly or indirectly through the tax sys-
tem. An example might be research on basic science. Second, the government may un-
dertake to provide the public good itself and to pay the costs of providing the service
through the revenues raised by compulsory taxation. This is, in fact, how national de-
fense is supplied.

Web Note 2.1

Another kind of problem that markets have is coordinating people, especially
when they act collectively. See our website for a discussion of coordination
and collective action applied to legal issues.

4. Severe Informational Asymmetries The fourth source of market failure
is an imbalance of information between parties to an exchange, one so severe that ex-
change is impeded.

To illustrate, it is often the case that sellers know more about the quality of goods
than do buyers. For example, a person who offers his car for sale knows far more about
its quirks than does a potential buyer. Similarly, when a bank presents a depository
agreement for the signature of a person opening a checking account, the bank knows
far more than the customer about the legal consequences of the agreement.

When sellers know more about a product than do buyers, or vice versa, informa-
tion is said to be distributed asymmetrically in the market. Under some circumstances,
these asymmetries can be corrected by the mechanism of voluntary exchange, for ex-
ample, by the seller’s willingness to provide a warranty to guarantee the quality of a
product. But severe asymmetries can disrupt markets so much that a social optimum
cannot be achieved by voluntary exchange. When that happens, government interven-
tion in the market can ideally correct for the informational asymmetries and induce
more nearly optimal exchange. For example, the purchasers of a home are often at a

42 C H A P T E R 2 A Brief Review of Microeconomic Theory

disadvantage vis-à-vis the current owners in learning of latent defects, such as the pres-
ence of termites or a cracked foundation. As a result, the market for the sale of homes
may not function efficiently; purchasers may be paying too much for homes or may in-
efficiently refrain from purchases because of a fear of latent defects. Many states have
responded by requiring sellers to disclose knowledge of any latent defects to prospec-
tive purchasers of houses. If the sellers do not make this disclosure, then they may be
responsible for correcting those defects.

Web Note 2.2

One of the most important issues in welfare economics has been the deriva-
tion of a social welfare function, which aggregates individual preferences into
social preferences. The Arrow Impossibility Theorem, one of the most signifi-
cant intellectual achievements of modern economics, argues that a social
welfare function with minimally desirable properties cannot be constructed.
We describe the theorem in more detail at our website.

C. Potential Pareto Improvements or Kaldor-Hicks Efficiency
Dissatisfied with the Pareto criterion, economists developed the notion of a

potential Pareto improvement (sometimes called Kaldor-Hicks efficiency). This is an
attempt to surmount the restriction of the Pareto criterion that only those changes are
recommended in which at least one person is made better off and no one is made worse
off. That criterion requires that gainers explicitly compensate losers in any change. If
there is not explicit payment, losers can veto any change. That is, every change must be
by unanimous consent. This has clear disadvantages as a guide to public policy.

By contrast, a potential Pareto improvement allows changes in which there are both
gainers and losers but requires that the gainers gain more than the losers lose. If this con-
dition is satisfied, the gainers can, in principle, compensate the losers and still have a
surplus left for themselves. For a potential Pareto improvement, compensation does not
actually have to be made, but it must be possible in principle. In essence, this is the tech-
nique of cost-benefit analysis. In cost-benefit analysis, a project is undertaken when its
benefits exceed its costs, which implies that the gainers could compensate the losers.
Cost-benefit analysis tries to take into account both the private and social costs and ben-
efits of the action being contemplated. There are both theoretical and empirical prob-
lems with this standard, but it is indispensable to applied welfare economics.

Consider how these two criteria—the Pareto criterion and the Kaldor-Hicks
criterion—would help us to analyze the efficiency and distributive justice of a manu-
facturing plant’s decision to relocate. Suppose that the plant announces that it is going
to move from town A to town B. There will be gainers—those in town B who will be
employed by the new plant, the retail merchants and home builders in B, the sharehold-
ers of the corporation, and so on. But there will also be losers—those in town A who
are now unemployed, the retail merchants in A, the customers of the plant who are now
located further away from the plant, and so on. If we were to apply the Pareto criterion

X. Decision Making Under Uncertainty: Risk and Insurance 43

to this decision, the gainers would have to pay the losers whatever it would take for
them to be indifferent between the plant’s staying in A and moving to B. If we were to
apply the potential Pareto criterion to this decision, the gainers would have to gain
more than the losers lose but no compensation would actually occur.

Web Note 2.3

See our website for much more on cost-benefit analysis as a guide to public
policy, including legal change.

X. Decision Making Under Uncertainty: Risk
and Insurance

In nearly all of the economic models we have examined so far, we have implicitly
assumed that uncertainty did not cloud the decision. This is clearly a simplifying as-
sumption. It is time to expand our basic economic model by explicitly allowing for the
presence of uncertainty.

A. Expected Monetary Value
Suppose that an entrepreneur is considering two possible projects in which to in-

vest. The first, involves the production of an output whose market is familiar and
stable. There is no uncertainty about the outcome of project the entrepreneur can
be confident of earning a profit of $200 if he takes The second course of action,
involves a novel product whose reception by the consuming public is uncertain. If con-
sumers like the new product, the entrepreneur can earn profits of $300. However, if
they do not like it, he stands to lose $30.

How is the entrepreneur supposed to compare these two projects? One possibility
is to compare their expected monetary values. An expected value is the sum of the
probabilities of each possible outcome times the value of each of those outcomes. For
example, suppose that there are four possible numerical outcomes, labeled through

to a decision. Suppose also that there are four separate probability estimates, la-
beled through associated with each of the four outcomes. If these are the only
possible outcomes, then these probabilities must sum to 1. The expected value (EV) of
this decision is then:

To return to our example, the entrepreneur can get $200 by choosing What is
the expected monetary value of decision There are two possible outcomes, and in
order to perform the calculation the entrepreneur needs to know the probabilities. Let p
denote the probability of the new product’s succeeding. Thus, is the probabil-
ity that it fails. Then, the expected monetary value of for any probability p is given
by the expression:

EMV(D2) = 300p + (-30)(1 – p).

D2

(1 – p)

D2?
D1.

EV = p1O1 + p2O2 + p3O3 + p4O4.

p4,p1

O4,
O1

D2,D1.
D1;

D1,

44 C H A P T E R 2 A Brief Review of Microeconomic Theory

Thus, if the probability of success for the new product equals the expected
monetary value of the decision to introduce that new product equals $80.

Where does the decision maker get information about the probabilities of the
various outcomes? Perhaps the seasoned entrepreneur has some intuition about p or
perhaps marketing surveys have provided a scientific basis for assessing p. Still an-
other possibility might be that he calculates the level of p that will make the expected
monetary value of equal to that of the certain event, A strong reason for doing
that would be that, although he might not know for sure what p is, it would be valu-
able to know how high p must be in order for it to give the same expected profits as
the safe course of action, For example, even if there was no way to know p for
sure, suppose that one could calculate that in order for the uncertain course of action
to have a higher expected value than the safe course of action, the probability of suc-
cess of the new product would have to be 0.95, a near certainty. That would be valu-
able information.

It is a simple matter to calculate the level of p that equates the expected monetary
value of and That is the p that solves the following equation:

which implies that The implication, of course, is that if the probability of the
new product’s success is .7 or greater, then has a higher expected monetary value
than does and the entrepreneur will choose

B. Maximization of Expected Utility: Attitudes Toward Risk
Do people deal with uncertainty by maximizing expected monetary values?

Suppose that the two decisions of the previous section, and have the same ex-
pected monetary value. Would you be indifferent between the two courses of action?
Probably not. is a sure thing. is not. Upon reflection, many would hesitate to take

unless the expected monetary value of was greater than that of The reason
for this hesitation may lie in the fact that many of us are reluctant to gamble, and
certainly is a gamble. We are generally much more comfortable with a sure thing like

Can we formalize our theory of decision making under uncertainty to take account
of this attitude?

The formal explanation for this phenomenon of avoiding gambles was first offered
in the eighteenth century by the Swiss mathematician and cleric Daniel Bernoulli.
Bernoulli often noticed that people who make decisions under uncertainty do not at-
tempt to maximize expected monetary values. Rather, they maximize expected utility.
The introduction of utility allows us to introduce the notion of decision makers’ atti-
tudes toward risk.

1. Risk Aversion Assume that utility is a function of, among other things, money
income:

U = U(I).

D1.

D2

D1.D2D2

D2D1

D2,D1

D2.D1

D2

p = .7.

300p – 30(1 – p) = 200,

D2.D1

D1.

D1.D2

1
3,

X. Decision Making Under Uncertainty: Risk and Insurance 45

Bernoulli suggested that a common relationship between money income and
utility was that as income increased, utility also increased, but at a decreasing rate.
Such a utility function exhibits diminishing marginal utility of income. For exam-
ple, if one’s income level is $10,000, an additional $100 in income will add more to
one’s total utility than will $100 added to that same person’s income of $40,000. A
utility function like that shown in Figure 2.16 has this property. When this person’s
income is increased by $1000 at a low level of income, her utility increases from
100 to 125 units, an increase of 25 units. But when her income is increased by
$1000 at a higher level of income, her utility increases from 300 to 310 units, an in-
crease of only 10 units.

A person who has diminishing marginal utility from money income is said to be
risk-averse. Here is a more formal definition of risk aversion:

A person is said to be risk-averse if she considers the utility of a certain prospect of
money income to be higher than the expected utility of an uncertain prospect of equal
expected monetary value.

For example, in the preceding entrepreneur’s project, a risk-averse decision maker
might prefer to have $80 for certain rather than undertake a project whose EMV
equals $80.

2. Risk Neutrality Economists presume that most people are averse toward risk,
but some people are either neutral toward risk or, like gamblers, rock climbers, and race
car drivers, prefer risk. Like aversion, these attitudes toward risk may also be defined
in terms of the individual’s utility function in money income and the marginal utility of
income.

Someone who is risk neutral has a constant marginal utility of income and is,
therefore, indifferent between a certain prospect of income and an uncertain
prospect of equal expected monetary value. Figure 2.17 gives the utility function for
a risk-neutral person. It is a straight line because the marginal utility of income to a
risk-neutral person is constant.

The figure compares the change in utility when the risk-neutral person’s income
is increased by $1000 at two different levels of income. When this person’s income is

Utility

310
300

125

100

0

U = U(I)

$1,000 $1,000

Income

FIGURE 2.16
Risk aversion as diminishing marginal
utility of income.

46 C H A P T E R 2 A Brief Review of Microeconomic Theory

increased by $1000 at a low level of income, his utility increases from 80 to 100 units,
an increase of 20 units. And when his income is increased by $1000 at a high level of
income, his utility increases by exactly the same amount, 20 units, from 160 to 180
units. Thus, for the risk-neutral person the marginal utility of income is constant.

Economists and finance specialists very rarely attribute an attitude of risk-neutrality
to individuals. However, they quite commonly assume that business organizations are
risk-neutral.

3. Risk-Seeking or Risk-Preferring Someone who is risk-seeking or risk-
preferring has an increasing marginal utility of income and, therefore, prefers an un-
certain prospect of income to a certain prospect of equal expected monetary value.
Figure 2.18 gives the utility function of a risk-preferring individual. The figure allows
us to compare the change in utility when the risk-preferring person’s income is
increased by $1000 at two different levels of income. When this person’s income is in-
creased by $1000 at a low level of income, her utility increases from 80 to 85 units, an
increase of 5 units. However, when her income is increased by $1000 at a high level of
income, her utility increases from 200 to 230 units, an increase of 30 units. Thus, for
the risk-preferring person the marginal utility of income increases.

Web Note 2.4

One of the winners of the Nobel Prize in Economics in 2002 was Daniel
Kahneman, Professor Emeritus of Psychology at Princeton University.
Kahneman and his coauthor, the late Amos Tversky, did experiments to see
the extent to which people’s attitudes toward risk fit those we have just stud-
ied. The experiments suggested that most people have complex feelings about
losses and gains that Kahneman and Tversky characterized as “loss aversion.”
See section XII, on page 50 and our website for more on the experiments and
their implications.

Utility

180
160

100
80

U = U(I)

$1,000 $1,000

Income
0

FIGURE 2.17
Risk neutrality as constant marginal
utility of income.

X. Decision Making Under Uncertainty: Risk and Insurance 47

C. The Demand for Insurance
One of the most important behavioral implications of risk aversion is that people

will pay money to avoid having to face uncertain outcomes. That is, a risk-averse per-
son might prefer a lower certain income to a higher uncertain income.

There are three ways in which a risk-averse person may convert an uncertain
into a certain outcome. First, he may purchase insurance from someone else. In ex-
change for giving up a certain amount of income (the insurance premium), the in-
surance company will bear the risk of the uncertain event. The risk-averse person
considers himself better off with the lower certain income than facing the uncertain
higher income. Second, he may self-insure. This may involve incurring expenses to
minimize the probability of an uncertain event’s occurring or to minimize the mone-
tary loss in the event of a particular contingency. An example is the installation of
smoke detectors in a home. Another form of self-insurance is the setting aside of a
sum of money to cover possible losses. Third, a risk-averse person who is consider-
ing the purchase of some risky asset may reduce the price he is willing to pay for
that asset.

D. The Supply of Insurance
The material of the previous section concerns the demand for insurance by risk-

averse individuals. Let us now turn to a brief consideration of the supply of insurance
by profit-maximizing insurance companies.

Insurance companies are presumed to be profit-maximizing firms. They offer in-
surance contracts not because they prefer gambles to certainties but because of a math-
ematical theorem known as the law of large numbers. This law holds that unpredictable
events for individuals become predictable among large groups of individuals. For ex-
ample, none of us knows whether our house will burn down next year. But the occur-
rence of fire in a city, state, or nation is regular enough so that an insurance company
can easily determine the objective probabilities. By insuring a large number of people,
an insurance company can predict the total amount of claims.

Utility

230
200

85
80

U = U(I)

$1,000 $1,000

Income
0

FIGURE 2.18
Risk preferring as increasing marginal
utility of income.

48 C H A P T E R 2 A Brief Review of Microeconomic Theory

1. Moral Hazard Moral hazard arises when the behavior of the insured person or
entity changes after the purchase of insurance so that the probability of loss or the size of
the loss increases. An extreme example is the insured’s incentive to burn his home when
he has been allowed to insure it for more than its market value. A more realistic example
comes from loss due to theft. Suppose that you have just purchased a new sound system
for your car but that you do not have insurance to cover your loss from theft. Under these
circumstances you are likely to lock your car whenever you leave it, to park it in well-
lighted places at night, to patronize only well-patrolled parking garages, and so on.

Now suppose that you purchase an insurance policy that will, unrealistically, com-
pensate you for the full cost of any insured loss that you suffer. With the policy in force
you now may be less assiduous about locking your car or parking in well-lighted
places. In short, the very fact that your loss is insured may cause you to act so as to in-
crease the probability of a loss.

Insurance companies attempt to set their premiums so that, roughly, the premium
modestly exceeds the expected monetary value of the loss. Therefore, a premium that
has been set without regard for the increased probability of loss due to moral hazard
will be too low and thus threaten the continued profitability of the firm. Every insurer
is aware of this problem and has developed methods to minimize it. Among the most
common are coinsurance and deductibles. Under coinsurance the insuree shoulders a
fixed percentage of his loss, with the insurer picking up the remaining portion of the
loss; under a deductible plan, the insuree shoulders a fixed dollar amount of the loss,
with the insurance company paying for all losses above that amount. In addition, some
insurance companies offer reductions in premiums for certain easily established acts
that reduce claims. For example, life and health insurance premiums are less for non-
smokers; auto insurance premiums are less for nondrinkers; and fire insurance rates are
lower for those who install smoke detectors.

2. Adverse Selection The other major problem faced by insurance companies is
called adverse selection. This arises because of the high cost to insurers of accurately
distinguishing between high- and low-risk insurees. Although the law of large numbers
helps the company in assessing probabilities, what it calculates from the large sample
are average probabilities. The insurance premium must be set using this average proba-
bility of a particular loss. For example, insurance companies have determined that un-
married males between the ages of 16 and, say, 25, have a much higher likelihood of
being in an automobile accident than do other identifiable groups of drivers. As a re-
sult, the insurance premium charged to members of this group is higher than that
charged to other groups whose likelihood of accident is much lower.

But even though unmarried males between the ages of 16 and 25 are, on average,
much more likely to be involved in an accident, there are some young men within that
group who are even more reckless than average and some who are much less reckless than
the group’s average. If it is difficult for the insurer to distinguish these groups from the
larger group of unmarried males aged 16 to 25, then the premium that is set equal to the
average likelihood of harm within the group will seem like a bargain to those who know
they are reckless and too high to those who know that they are safer than their peers.

Let us assume, as seems reasonable, that in many cases the individuals know bet-
ter than the insurance company what their true risks are. For example, the insured alone

XI. Profits and Growth 49

may know that he drinks heavily and smokes in bed or that he is intending to murder
his spouse, in whose insurance policy he has just been named principal beneficiary. If
so, then this asymmetrical information may induce only high-risk people to purchase
insurance and low-risk people to purchase none. As a result, the insurance company
will find itself paying out more in claims than it had anticipated. It may, therefore, raise
the premiums higher. This will drive out some more relatively safer customers, leaving
an even-riskier clientele behind. The incidence and volume of claims may go up yet
again, setting off a new round of premium increases, defections of less-risky customers,
and so on. This process is referred to as an insurance death spiral.

The same devices that insurance companies employ to minimize risks of moral haz-
ards also may serve to minimize the adverse selection problem. Coinsurance and de-
ductible provisions are much less attractive to high-risk than to low-risk insurees so that
an insuree’s willingness to accept those provisions may indicate to the insurance com-
pany to which risk class the applicant belongs. Exclusion of benefits for loss arising from
preexisting conditions is another method of trying to distinguish high- and low-risk peo-
ple. The insurer can also attempt, over a longer time horizon, to reduce the adverse selec-
tion bias by developing better methods of discriminating among the insured, such as
medical and psychological testing, so as to place insurees in more accurate risk classes.
Finally, insurers frequently practice experience rating—the practice of adjusting the in-
suree’s premium up or down according to his experience of insurable losses. If an insuree
appears to be accident prone, then the insurer may raise his premium to reflect the greater
probability or size of loss. In the limit, the insurer may refuse to cover the insuree.

XI. Profits and Growth15

Imagine a banker who asks to be paid by placing one penny on the first square of a chess
board, two pennies on the second square, four on the third, and so on. Using only the white
squares, the initial penny would double in value thirty-one times, leaving $21.5 million on
the last white square. Growth compounds faster than the mind can grasp. In 1900 Argentina’s
income per person resembled Canada’s, and today Canada’s is more than three times higher.
After World War II, Korea and Nigeria had similar national income per person, and today
Korea’s is nineteen times higher. Most people cannot imagine China with more economic in-
fluence in the world than the United States, but, if current trends continue, China will surpass
the United States in national income in 2014.16 Lifting so many people out of poverty in East
Asia in the late twentieth century is one of history’s remarkable accomplishments. In con-
trast, one of history’s depressing economic failures in the late twentieth century is sub-
Saharan Africa, where GDP per person declined since 1975 roughly by 25 percent.

Why do some countries grow faster than others? Sustained growth requires innovation.
An innovation occurs when someone discovers a better way to make something or some-
thing better to make. Entrepreneurs make things in better ways by improving organizations

15 This section draws on Chapter 1 of ROBERT COOTER & HANS-BERND SCHAEFER, LAW AND THE POVERTY OF

NATIONS (2011).
16 Because China’s population is 4 to 5 times greater than the United States’ population, China’s income per

capita in 2014 will still be one-fourth to one-fifth that of the United States. This prediction was made by
Carl J. Dahlman, Luce Professor of International Affairs and Information, Georgetown University.

50 C H A P T E R 2 A Brief Review of Microeconomic Theory

and markets, and scientists invent better things to make. Growth will remain mysterious un-
til economics has an adequate theory of innovation. The only contribution to growth theory
so far that merited a Nobel Prize in Economics shows the consequences of innovation for
capital and labor but does not attempt to explain innovation.17

Law, we believe, is part of the mystery’s solution. When an innovator has a new
idea, it must be developed in order for the economy to grow. Combining new ideas and
capital runs into a fundamental obstacle illustrated by this example: An economist who
worked at a Boston investment bank received a letter that read, “I know how your bank
can make $10 million. If you give me $1 million, I will tell you.” The letter captures
concisely the problem of financing innovation: The bank does not want to pay for in-
formation without first determining its worth, and the innovator fears disclosing infor-
mation to the bank without first getting paid. Law is central to solving this problem.
Later chapters in this book mention “transactional lawyers,” who use law to overcome
the mistrust that prevents people from cooperating in business. The most fundamental
bodies of transaction law are property and contracts, which we cover in Chapters 4, 5,
8, and 9. Making these bodies of law efficient promotes economic growth by uniting
innovative ideas and capital. Countries with efficient property and contract have estab-
lished the legal foundation for innovation and growth.

XII. Behavioral Economics
In our review of microeconomic theory we have followed modern microecono-

mists in assuming that decision makers are rationally self-interested. This theory of de-
cision making is called rational choice theory and has served the economics profession
well over the past 60 or more years in theorizing about how people make explicitly eco-
nomic decisions. But rational choice theory has been under attack over the past 30
years or so. This attack has been principally empirical. That is, it has been premised on
experimental findings that people do not behave in the ways predicted by rational
choice theory. (We will give examples shortly.)

Two principal names in the experimental literature that have been critical of rational
choice theory are Daniel Kahneman and Amos Tversky. As we noted above, Kahneman
won the Nobel Prize in Economics in 2002. The body of literature inspired by
Kahneman and Tversky has as acquired the name behavioral economics and the legal
analysis that takes account of these findings is called behavioral law and economics.18

What are some examples of behavioral economics? Let us consider two (although
there are many others) that have particular relevance to the law. The first is the result of
experiments involving the ultimatum bargaining game. In that game there are two play-
ers, neither of whom knows the identity of the other. They interact anonymously. Their
task in the game is to divide a small sum of money—say, $20. One player is designated

17 In 1987 Robert Solow received the Nobel Prize in Economics for his contributions to economic growth
theory.

18 For a summary of the field, see Russell B. Korobkin & Thomas S. Ulen, Law and Behavioral Science:
Removing the Rationality Assumption from Law and Economics, 88 CAL. L. REV. 1051 (2000).

XII. Behavioral Economics 51

Player 1; the other, Player 2. Player 1 makes some proposal to Player 2 about how the
$20 should be divided; Player 2 can then either accept that proposal, in which case the
experimenter actually gives the two players the amounts proposed by Player 1, or re-
ject the proposal, in which case neither player gets any money.

Rational choice theory predicts that Player 1 will take advantage of her position as the
proposer to give herself a disproportionate share of the $20—say, $15, leaving $5 for Player
2. Player 1 might also reason that Player 2 will take $5 rather than nothing. And, in fact,
Player 2 might think that Player 1 is selfish, but that, after all, $5 is better than nothing.

This game has been played in experiments in over 140 countries and among groups
with vastly different incomes, ages, education levels, religions, and the like, and in
countries that are wealthy and countries that are poor. The modal (most common) out-
come is a 50-50 split of the stakes—each player gets $10. Equally interesting is the fact
that in many countries if Player 1 tries to take more than 70 percent of the stakes (more
than $14 in our $20 example), Player 2 rejects the offer and they each get nothing.19

We take some heart from the fact that strangers seldom take advantage of one an-
other in the ultimatum bargaining game. Rather, the norm seems to be to treat the other
party fairly; in fact, to treat him or her exactly as one treats oneself. Are there legal im-
plications of this insight? We return to this point in Chapters 8 and 9 when we consider
the concern of contract law with some forms of advantage-taking in bargaining.

A second example of a behavioral economics finding is the hindsight bias. This
refers to the fact that things that actually happen seem, in hindsight (ex post), to have
been far more likely than they were in foresight (ex ante). So, if you asked people in
spring 2010 the probability that Spain would win the 2010 World Cup in South
Africa, they might have said, “10 percent.” But if you ask them after Spain actually
won the cup, they will say it was much more likely—say, 40 percent. Is there a legal
implication? Consider something that we will discuss in Chapter 6: How do we in-
duce someone to take the right amount of precaution against harming another per-
son? As we will see, one way to do that is to expose the possible injurer to liability
for the injuries that a victim suffers if the injurer did not take a prudent amount of
precaution. Here’s the problem—what might seem prudent precaution before an ac-
cident occurs might appear, in hindsight, to have been imprudent. That is, if an acci-
dent has occurred, the hindsight bias may tell us that the accident was more
inevitable than we would have thought before.

Rational choice theory cannot explain the observed behavior in the ultimatum bar-
gaining game or hindsight bias. The central insight of behavioral economics is that hu-
man beings make predictable errors in judgment, cognition, and decision making. They
are, to quote the title of a book on this topic by Dan Ariely, “predictably irrational.”
Economic analysis should use rational choice theory or behavioral theory, depending
on which one predicts the law’s effects on the behavior more accurately.

19 The group that typically plays this game in line with the predictions of rational choice theory (in which
Player 1 makes a proposal to take much more than half of the stakes and Player 2 accepts that) are gradu-
ate students in economics. Did they select a graduate study in economics because they already find ra-
tional choice theory attractive? Or did their graduate studies in economics convince them that rational
choice was the appropriate way to behave?

52 C H A P T E R 2 A Brief Review of Microeconomic Theory

Review Questions
If you are not certain whether you need to refresh your understanding of microeco-

nomic theory, try these questions. If you find them to be too hard, read this chapter and
try them again. If only some of the questions are too hard, turn to the section of the
chapter that covers that material and review that section.

2.1. Define the role of the mathematical concepts of maximization and
equilibrium in microeconomic theory.

2.2. Define and distinguish between productive efficiency and allocative efficiency.

2.3. What are consumers assumed to maximize? What are some constraints under
which this maximization takes place? Describe the individual consumer’s
constrained maximum. Can you characterize this constrained maximum as a
point where marginal cost and marginal benefit are equal?

2.4. A married couple with children is considering divorce. They are negotiating
about two elements of the divorce: the level of child support that will be paid
to the partner who keeps the children, and the amount of time that the
children will spend with each partner. Whoever has the children would prefer
more child support from the other partner and more time with the children.
Furthermore, the partner who keeps the children believes that as the amount
of child support increases, the value of more time with the children declines
relative to the value of child support.

a. Draw a typical indifference curve for the partner who keeps the children
with the level of child support on the horizontal axis and the amount of
time that the children spend with this partner on the vertical axis. Is this
indifference curve convex to the origin? Why or why not?

b. Suppose that the partner who keeps the children has this utility function
where the weekly level of child support and the number

of days per week that the children spend with this partner. Suppose that
initially the weekly support level is $100, and the number of days per
week spent with this partner is 4. What is the utility to this partner from
that arrangement? If the other partner wishes to reduce the weekly support
to $80, how many more days with the children must the child-keeping
partner have in order to maintain utility at the previous level?

2.5. Define price elasticity of demand and explain what ranges of value it may take.

2.6. Use the notion of opportunity cost to explain why “There’s no such thing as a
free lunch.”

2.7. True or False: The cost of a week of vacation is simply the money cost of the
plane, food, and so forth. (Explain your answer.)

2.8. What are firms assumed to maximize? Under what constraints do firms
perform this maximization? Describe how the individual firm determines the
output level that achieves that maximum. Can you characterize the firm’s
constrained maximum as one for which marginal cost equals marginal benefit?

2.9. Characterize these different market structures in which a firm may operate:
perfect competition, monopoly, oligopoly, and imperfect competition.

v =c =u = cv,

Review Questions 53

Compare the industry output and price in a perfectly competitive industry
with the output and price of a monopolist.

2.10. What conditions must hold for a monopoly to exist?

2.11. Suppose that the local government determines that the price of food is too high
and imposes a ceiling on the market price of food that is below the equilibrium
price in that locality. Predict some of the consequences of this ceiling.

2.12. The minimum wage is typically set above the market-clearing wage in the
market for labor. Using a graph with an upward-sloping supply of labor, a
downward-sloping demand for labor, with the quantity of labor measured on the
horizontal axis and the wage rate measured on the vertical axis, show the effect
on the labor market of a minimum wage set above the equilibrium wage rate.

2.13. True or False: In Japan, workers cannot be fired once they have been hired;
therefore, in Japan a minimum wage law (where the minimum would be set
above the wage that would cause the market for labor to clear) would not
cause unemployment.

2.14. In the United States in the late twentieth century, no-fault divorce laws became
the norm in the states (divorce being a matter for states, not the federal
government, to regulate). Ignoring for the sake of this problem all the other
factors that influence the marriage decision and that have changed during the
same time period, what does the move to no-fault divorce do to the implicit
(legal) price of divorce? What would be your prediction about the effect of this
change in the implicit price of divorce on the quality and quantity of marriages
and divorces? If, in the next decade, the states were to repudiate the experiment
in no-fault divorce and return to the old regime, would you predict a change in
the quality and quantity of marriages and divorces?

2.15. The Truth-in-Lending Act (15 U.S.C. §§1601–1604 (1982)) requires the uniform
disclosure of the interest rate to borrowers in a readily intelligible form. Assume
that before the act, there was uncertainty among borrowers about the true level of
the interest rate, but that after the act, that uncertainty is reduced. What effect on
the amount of borrowing would you predict from passage of the act? Would
there be disproportionate effects on the poor and the rich? Why? Does the act
increase the marginal cost of lenders? Does it reduce the profits of lenders?

2.16. What is general equilibrium and under what conditions will it be achieved?
What are the welfare consequences of general equilibrium?

2.17. What are the four sources of market failure? Explain how each of them
causes individual profit- and utility-maximizers to make decisions that may
be privately optimal but are socially suboptimal. What general policies might
correct each of the instances of market failure?

2.18. Which of the following are private goods and might, therefore, be provided
in socially optimal amounts by private profit-maximizers? Which are public
goods and should, therefore, be provided by the public sector or by the
private sector with public subsidies?

a. A swimming pool large enough to accommodate hundreds of people.
b. A fireworks display.

54 C H A P T E R 2 A Brief Review of Microeconomic Theory

c. A heart transplant.
d. Vaccination against a highly contagious disease.
e. A wilderness area.
f. Vocational education.
g. On-the-job training.
h. Secondary education.

2.19. What is meant by Pareto efficiency or Pareto optimality? What is the importance
of the initial distribution of resources in determining what the distribution of
resources will be after all Pareto improvements have been made?

2.20. A valuable resource in which we typically forbid voluntary exchange is
votes. This may be inefficient in that, as we have seen, given any initial
endowment of resources, voluntary exchange always makes both parties
better off (absent any clear sources of market failure). Show that it would be
a Pareto improvement if we were to allow a legal market for votes. Are there
any clear sources of market failure in the market for votes? If so, what
regulatory correctives would you apply to that market? Is it bothersome that
there is a wide variance in income and wealth among the participants in this
market, and if so, why is that variance more troubling in this market than in
others, and what would you do about it in the market for votes?

2.21. Distinguish between the Pareto criterion for evaluating a social change in
which there are gainers and losers and the Kaldor-Hicks (or potential Pareto)
criterion.

2.22. What is a dominant strategy in a game? Where both players in a two-person game
have a dominant strategy, is there an equilibrium solution for the game? What is a
Nash equilibrium? Is a dominant-strategy equilibrium a Nash equilibrium? What
are the possible shortcomings of a Nash equilibrium in a game?

Suggested Readings

ARIELY, DAN, PREDICTABLY IRRATIONAL, REVISED AND EXPANDED EDITION: THE HIDDEN FORCES

THAT SHAPE OUR DECISIONS (2010).

EATWELL, JOHN, MURRAY MILGATE, & PETER NEWMAN, EDS., THE NEW PALGRAVE: A DICTIONARY

OF ECONOMICS, 4 vols. (1991).

KREPS, DAVID, A COURSE IN MICROECONOMIC THEORY (1990).

LANDSBURG, STEPHEN, THE ARMCHAIR ECONOMIST (1991).

LEVITT, STEVEN D., & STEVEN J. DUBNER, FREAKONOMICS: A ROGUE ECONOMIST EXPLAINS THE

HIDDEN SIDE OF EVERYTHING (2005).

LEVITT, STEVEN D., & STEVEN J. DUBNER, SUPERFREAKONOMICS: GLOBAL WARMING, PATRIOTIC

PROSTITUTES, AND WHY SUICIDE BOMBERS SHOULD BUY LIFE INSURANCE (2009).

PINDYK, ROBERT, & DANIEL RUBINFELD, MICROECONOMICS (6th ed. 2004).

THALER, RICHARD H., & CASS R. SUNSTEIN, NUDGE: IMPROVING DECISIONS ABOUT HEALTH,
WEALTH, AND HAPPINESS (2008).

WINTER, HAROLD, TRADE-OFFS AN INTRODUCTION TO ECONOMIC REASONING AND SOCIAL ISSUES

(2005).

“You are old,” said the youth, “and your jaws are too weak
For anything tougher than suet.
Yet you finished the goose, with the bones and the beak.
Pray, how do you manage to do it?”
“In my youth,” said his father, “I took to the law,
And argued each case with my wife.
And the muscular strength, which it gave to my jaw,
Has lasted the rest of my life.”

From “Father William” in LEWIS CARROLL,
ALICE’S ADVENTURES IN WONDERLAND

The life of the law has not been logic: it has been experience. The felt necessities of the
time, the prevalent moral and political theories, institutions of public policy, avowed
or unconscious, even the prejudices which judges share with their fellow-men, have
had a good deal more to do than the syllogism in determining the rules by which men
should be governed.

OLIVER WENDELL HOLMES,
THE COMMON LAW 1 (1881)

AN ECONOMIST WHO picks up a law journal will understand much more of it than
a lawyer who picks up an economics journal. For this reason, it is not hard to
convince a lawyer that he does not know economics. (Convincing him that he

should learn economics is harder!) On the other hand, economists are sometimes hard
to convince that any aspect of social life is not, at its root, really economics. With re-
spect to the law, economists sometimes wonder what lawyers really study: Is the law a
branch of philosophy? Is it a list of famous cases? Is it a collection of rules?

In any case, economists cannot contribute significantly to law without studying it.
This chapter provides an introduction to the law for nonlawyers. We shall explain, first,
differences and similarities between the two great legal traditions that spread from
Europe to much of the world; second, the structure of the United States’ federal and
state court systems; third, how a legal dispute gets raised and resolved in systems like
that of the United States; and finally, how the legal rules made by judges evolve.

55

3 A Brief Introduction to Law
and Legal Institutions

56 C H A P T E R 3 A Brief Introduction to Law and Legal Institutions

I. The Civil Law and the Common Law Traditions
Legislatures make laws by enacting bills, which judges must interpret and apply. If

legislation is deliberately vague or inadvertently ambiguous, judges can choose among
several different interpretations. Sometimes the choice of an interpretation overshad-
ows the enactment of the bill, in which case the judge makes the law more than the leg-
islature. Judges make law by interpreting legislation in all legal systems with
independent courts.

Judges make law in other ways as well. In medieval Europe, the king in most coun-
tries could issue pronouncements that were law, and the king’s courts possessed similar
powers. However, the king’s courts were not free to pronounce as law any command
that they wished. According to one tradition in legal theory, the courts of the English
king were to examine community life and “find” law as it already existed. The courts
of the English king were to select among prevailing social norms and enforce some of
them. These enforceable social norms were supposedly the “laws of nature,” which rea-
son and necessity prescribed.

The finding of a rule of law by a court of the English king created a precedent that
future courts were expected to follow.1 A precedent in common law resembles a gener-
ally accepted interpretation in civil law. Precedent was followed flexibly, not slavishly,
so the law changed gradually. Over many years, the king’s courts “found” many impor-
tant laws, especially in the areas of crimes, property, contracts, and accidents (“torts”).
These findings are called the “common law” because they are allegedly rooted in the
common practices of people. Common law is still applied in the English-language
countries, except where superseded by legislation.

Legal history is different in France and the other countries of Europe: When
France revolted at the end of the eighteenth century, the revolutionaries thought that the
judges were as corrupt and worthless as the king, so they killed the king and extin-
guished his laws, thus abolishing the common law of France. A comprehensive set of
statutes was required to fill the void, so people would know what counts as property,
how a valid contract is formed, and who is to bear the cost of accidents. Napoleon sup-
plied them by commissioning legal scholars to draft the rules called the Code
Napoléon, which was promulgated in 1804. The scholars who drafted it took as their
model the Corpus Juris Civilis (“The Body of the Civil Law”), which was compiled
and edited in A.D. 528–534 at the behest of the Roman emperor Justinian. Thus, the
French revolutionaries looked to ancient sources and pure reason for law, rather than to
the more immediate heritage derived from medieval times.

Napoleon’s armies spread the Code Napoléon through much of Europe, where it
remained long after his troops withdrew. Similarly, Europeans spread their law
throughout the world, and this influence persisted long after the colonial empires col-
lapsed. The “civil law tradition,” as it is called, predominates in most of Western

1 “Precedent” refers to the practice of resolving similar cases in a similar fashion. If it is known that a court
is going to resolve a dispute by applying precedent, then the disputants have a good idea what the legal res-
olution of their dispute might be. This can induce the disputants to settle the matter themselves against the
background law that they know the court will use.

I. The Civil Law and the Common Law Traditions 57

Europe, Central and South America, the parts of Asia colonized by European coun-
tries other than Britain, and even in pockets of the common law world, such as
Louisiana, Québec, and Puerto Rico. The common law tradition, which originated in
England, prevails not only in Great Britain, but also in Ireland, the United States,
Canada, Australia, New Zealand, and the parts of Africa and Asia that Britain
colonized, including India.

Besides these two great traditions, the unique history of each country puts its own
stamp on the law. For example, Japan, which was never colonized, voluntarily adopted a
code that draws heavily on the German civil code while yet remaining distinctively
Japanese. In much of the Middle East, Islamic law blended with, or displaced, the law
of the European colonialists. In Eastern Europe, communism bent the civil law tradition
to its own purposes, and now the post-Communist regimes are trying to straighten it.

The common law and civil law traditions differ significantly with respect to how
judge-made law is justified. Common law judges traditionally justify their findings of
law by reference to precedent and social norms, or by broad requirements of rationality
presupposed by public policy. Civil law judges traditionally justify their interpretation
of a code directly by reference to its meaning, which scholars tease out in lengthy com-
mentaries. Because common law judges rely relatively more on past court decisions
and civil law judges rely relatively more on the words in statutes, the common law sys-
tem is based more on precedent than the civil law system. The difference in the pattern
of justification affects the training of lawyers. The common law method is taught by
reading cases and arguing directly from them, whereas the civil law method is taught
by reading the code and arguing from commentaries on it.

All such generalizations about the difference between the two traditions, however,
seem simplistic relative to the subtlety and complexity of reality. For example, although
the United States is ostensibly a common law country, the American states have tried
to obtain greater uniformity in commercial law by enacting the Uniform Commercial
Code. Deciding disputes that fall under the Uniform Commercial Code in America has
many similarities to deciding disputes that fall under the French Civil Code.
Additionally, the American Law Institute, an organization founded in the 1920s, meets
periodically to restate the law as it is emerging in the various states. These restate-
ments, such as the Restatement (Second) of Contracts and the Restatement (Second) of
Torts, serve a similar function to the codes that are thought to be characteristic of the
civil law countries. Comparative law scholars vigorously debate whether the differ-
ences between civil and common law are more apparent than real.

Besides the difference in history between common and civil law, the laws are ap-
plied differently in the two traditions. In the common law countries, the arguments for
the two sides in a dispute are made exclusively by their lawyers, and the judge is not
supposed to direct a line of questioning or develop an argument. In this adversarial
process, the judge acts more or less as a neutral referee who makes the lawyers follow
the rules of procedure and evidence. The principle underlying the adversarial system is
that the truth will emerge from a vigorous debate by the two sides.

In contrast, the civil law judge takes an active role in directing questions and de-
veloping arguments. In this inquisitorial process, the judge is supposed to ferret out the
truth. The lawyers often have to respond to the judge, rather than develop the case

58 C H A P T E R 3 A Brief Introduction to Law and Legal Institutions

themselves. The principle underlying the inquisitorial system is that the court has a di-
rect interest in finding the truth regarding private disputes and crimes.

Another difference between the two systems concerns the use of juries. Juries are
more commonly used in common law systems. In America, either party to a dispute
usually has the right to a jury trial, although both parties sometimes waive this right and
allow the judge to decide the case. In England, the jury has been abolished in almost all
civil trials since 1966,2 but it is often used in criminal trials. (Notice the different use of
“civil” in the preceding sentence.3) In France, however, the jury has been abolished for
all trials except the most serious crimes, like murder. In general, the abolition of juries
is more advanced in continental Europe than in some common law countries. In a com-
mon law trial before a jury, the judge is supposed to decide questions of law, whereas
the jury is supposed to decide questions of fact.

In every legal system, laws form a hierarchy. The constitution takes precedence
over statutes, and statutes usually take precedence over rules issued by the executive or
government agencies. In countries with common law, statutes take precedence over it.
“Taking precedence” means that the higher law prevails in the event of conflict. The
courts, as the main interpreters of law, must decide whether laws conflict. We have ex-
plained that judges make law indirectly by interpreting statutes or codes. Another way
that judges make law is by finding a conflict between laws and setting aside the lower-
level law. Finally, judges make common law directly in those countries that maintain
the common law system—a process we explain later in this chapter.

Constitutions are necessarily general and vague, so their interpretation is espe-
cially problematic. The power to review legislation for its constitutionality gives
courts the power, in principle, to set aside laws enacted by the legislature. This power
is potentially dangerous because it brings judges into conflict with the elected repre-
sentatives of the nation. The extent to which this power is exercised varies greatly
from one country to another. In the United States, the federal courts have few limits
on their ability to strike down laws that, in the courts’ opinion, contradict the
Constitution. Some of the most profound laws in America have been made by courts
interpreting the Constitution, as in Brown v. Board of Education in 1954, which even-
tually ended laws mandating racial segregation of schools. In other countries, such as
Great Britain, the courts do not have the power to review statutes for their constitu-
tionality, and the courts never strike down legislation as unconstitutional. The scope
of constitutional review, which is fundamental to the power and prestige of courts,
has no necessary connection with whether the country’s legal tradition is common or
civil law.

2 Except in cases involving defamation.
3 “Civil law” has two meanings. It may refer to the system of law in most of continental Europe that rejects

common law. In addition, “civil law” may refer to laws controlling disagreements between two private par-
ties, which might arise, say, from a broken contract or an automobile accident. In this latter sense, the op-
posite of “civil law” is criminal or penal law, in which actions are initiated by the state’s prosecutor against
someone accused of violating a criminal statute, such as forgery or murder. Thus, the common law of, say,
contracts can be described as “civil law,” meaning “private law” or “not criminal law.”

II. The Institutions of the Federal and the State Court Systems in the United States 59

II. The Institutions of the Federal and the State Court
Systems in the United States

In the United States, whether at the state or the federal level, the court systems are or-
ganized in three tiers. These tiers constitute a hierarchical pyramid, with a very broad base
of many courts, an intermediate level with a smaller number of courts, and a single court at
the top of the pyramid. At the lowest level are the trial courts of general jurisdiction. These
are the “entry-level” courts that first hear a wide array of civil and criminal disputes. The
trial courts of general jurisdiction are “courts of record”; that is, the proceedings are writ-
ten down and saved by the government. In the state systems these courts are usually organ-
ized along county lines. For example, in the State of Illinois there are 102 counties, and
each has a “Circuit Court” that serves as the trial court of general jurisdiction within the
county. These trial courts have different names in different states: In California they are
called “Superior Courts”; in New York State, “Supreme Courts.” The nearly universal prac-
tice is for each civil and criminal case to be tried to a single judge and possibly to a jury.

In the federal system the entire country is divided into 94 judicial districts, each of
which contains a federal district court, which is the trial court of general jurisdiction
for the federal judiciary. Every state in the Union has at least one federal district court,
and about half have only one. The District of Columbia has its own district court. The
larger states, where larger numbers of disputes involving federal questions arise, have
up to four district courts, usually organized along geographical divisions of the state.
New York has four districts: the Southern, the Northern, the Eastern, and the Western.
Illinois has three federal districts: the Northern, the Central, and the Southern. As the
volume of federal litigation has grown, Congress has responded not by creating more
districts but by appointing more judges within each district. One of the busiest districts
is the Southern District of New York, which contains most of New York City. As of
2010, there were 44 district judges in that district (and 15 magistrate judges).4 Another
busy district, the Northern District of Illinois, has 32 district judges (and 14 magistrate
judges).5 The usual procedure in the federal districts is for a single judge to hear each
case, but a three-judge panel sometimes hears a case.

In addition, the federal court system includes several specialized tribunals. For ex-
ample, there are special tax courts, and federal administrative agencies, such as the
Federal Communications Commission, have administrative law judges who hear argu-
ments about matters before those agencies. There is also, as we shall soon see, a special
appellate tribunal in the federal system for dealing with intellectual property cases.6

4 In the last edition of this book, there were 25 district judges in that district.
5 In the last edition there were 12 district judges in the Northern District of Illinois. Magistrate judges are ap-

pointed by district court judges in each federal district for renewable eight-year terms. Those magistrates pre-
side over trials for federal misdemeanor crimes and hear preliminary motions in more serious federal crimes
and pretrial motions for many civil cases. Magistrates may preside over federal civil trials if the parties consent.

6 As of August 2010, there were a total of 678 federal district court judges, 179 Court of Appeals judges,
9 judges on the Court of International Trade, and 9 justices of the United States Supreme Court for a total
of 875 federal judges. There are currently 98 vacancies in the federal judiciary. Because Article III of the
U.S. Constitution provides for these judges, the 875 federal judges are called “Article III judges.”

60 C H A P T E R 3 A Brief Introduction to Law and Legal Institutions

Above the trial courts in the state and federal systems are appellate courts or
courts of appeal. In most state court systems, there is only one court of appeal. But
about one-third of the states and the federal system have intermediate appellate courts
that stand between the trial courts of general jurisdiction and the highest court (the
court of last resort). For example, in Illinois there are five intermediate appellate dis-
tricts with a total of just over 50 justices. Where these courts exist, parties from the trial
court may appeal “as of right,” which means that so long as they are willing to pay the
costs involved, the parties may always seek appellate review of a lower court’s judg-
ment. Appeal is also a right in the federal system, at least from the district courts to the
intermediate courts of appeal.

While there may be a right for either party to appeal the judgment of the trial courts
of general jurisdiction, matters may be different if either party wishes to appeal the judg-
ment of an intermediate appellate court. In both the state and the federal judiciary, the
highest appellate court typically has a discretionary right of review. This means that the
Supreme Court of Illinois, the Supreme Court of the United States, and all other courts
of last resort may select which cases they will review, within certain limits. Some
cases—for example, disputes between two states—come to the United States Supreme
Court directly and without the discretion of the justices. And in many states the highest
court is obligated to review death sentences. Thus, the United States Supreme Court and
the highest courts in the states control most, but not all, of their docket.

An intermediate court of appeal in the federal judiciary is called the “Court of
Appeals for the ___ Circuit.” There are thirteen of these circuits, as Figure 3.1 indi-
cates. Eleven of these courts of appeal are numbered; for example, the First Circuit is
in New England; the Seventh Circuit covers Indiana, Illinois, and Wisconsin; and the
Ninth Circuit covers the West Coast, some of the mountain states, and Alaska and
Hawaii. The District of Columbia constitutes its own circuit and also has its own dis-
trict court. All the other circuits include several states. An unsuccessful litigant from

FL

NM

DE
MD

TX

OK

KS

NE

SD

NDMT

WY

CO
10

UT

ID

AZ

NV

WA

CA

OR

KY

ME
1

NY
2

PA
3

MI

MI VT

NH
MA

RI
CT

VAWV

OH
6INIL

7

NCTN
SC

ALMS

AR

LA
5

MO

IA8

MN
WI

NJ

GA
11

HI
9AK

9

Virgin
Islands

3

Guam

DC

Northern
Mariana
Islands

FEDERAL
Washington D.C.

(intellectual property)

D.C.
Washington

Puerto Rico
1

9

4

FIGURE 3.1
United States Courts
of Appeal and United
States District Courts.

II. The Institutions of the Federal and the State Court Systems in the United States 61

the federal district court can take an appeal, as a matter of right, to the court of appeals.
Those courts often sit in a panel of three judges. Sometimes, for a particularly signifi-
cant case, all of the circuit judges will sit together to decide the case. In that case the
court is said to be sitting en banc or “in bank.” Where more than one judge hears a case,
the matter is decided by majority vote.

There is also a special intermediate appellate court in the federal system just for
hearing matters regarding intellectual property: the United States Court of Appeals for
the Federal Circuit. Congress established that court in 1982. This is the only U.S. Court
of Appeals defined by its subject matter jurisdiction rather than by geography. The U.S.
Court of Appeals for the Federal Circuit assumed the jurisdiction of the U.S. Court of
Customs and Patent Appeals and the appellate jurisdiction of the U.S. Court of Claims.
There are 15 judges on the Federal Circuit.

The Supreme Court of the United States is the highest court in the federal judici-
ary. That court has nine members, consisting of the Chief Justice of the United States
and eight Associate Justices. All of the justices, rather than a panel, decide each case.
The Court begins its work on the first Monday in October and concludes its term some-
time in June of the following year. The workload of the Supreme Court increased sig-
nificantly until the 1980s; since then the number of opinions that the Supreme Court
issues has declined significantly. Typically, the justices decide less than 10 percent of
the cases submitted to them for review. There is lively dispute about whether this figure
is too large or too small. In the recent past some commentators have urged Congress to
establish a national court of appeals between the courts of appeals and the Supreme
Court. The argument is that this National Court would handle the more routine appeals
arising from the thirteen circuits (for example, those in which there is a split among the
circuits, which means that some circuits say the law is one way and other circuits say
the opposite). Proponents say this would free up the Supreme Court to devote more of
its energies to truly important cases.

Finally, there are rules that specify whether a dispute should be heard in the state
or the federal court system.7 This is often a matter of great strategic significance in an
attorney’s handling of a case. The general rules for deciding jurisdiction are relatively
straightforward. State courts have jurisdiction in disputes involving state statutes or in
civil actions between residents of that state or in cases arising under federal law when
Congress has not given exclusive jurisdiction to the federal courts.

The jurisdiction of the federal courts is defined by Congress, through the powers
assigned in the Constitution. That jurisdiction is limited to three principal areas:

1. Federal questions—that is, those matters arising under the United States
Constitution or federal laws or treaties.8

2. Cases to which the United States is a party. Typically, these are criminal
cases under federal statute law.

7 The rules for resolving whether a state or federal law should apply in a particular dispute are complex and
themselves constitute a special course in law school called “Conflict of Laws.”

8 There used to be a minimum dollar amount in controversy ($10,000) before a case could be a federal case,
even if it was a federal question. That minimum no longer applies to matters arising under federal law.

62 C H A P T E R 3 A Brief Introduction to Law and Legal Institutions

3. Diversity cases—any civil dispute, currently involving more than $75,000,
between citizens of different states. In the late eighteenth century, Congress
allowed these disputes to be removed from state to federal courts because
it felt that state loyalties were so strong that the citizen of another state
might lose in a state court, regardless of the merits of his or her case, sim-
ply because he or she was a “foreigner.”9

In the event that a federal district court hears a diversity dispute not involving a
federal question, the Court will generally apply the law of the state in which it sits.
Today diversity of citizenship is no longer as compelling a reason for the federal courts
to assume jurisdiction as it was 200 years ago. Indeed, former Chief Justice Burger
urged Congress to ease the caseload of the federal judiciary by entirely removing the
diversity cases from federal jurisdiction.10

As to the selection and tenure of judges, there are two broad practices. For the fed-
eral bench, the rule is appointment by the president with the advice and consent of
the Senate for life tenure with removal only by impeachment by the House of
Representatives and conviction by the Senate. For state judges in a majority of the
states, the rule is election to the bench and limited tenure. For the remainder of the
states, the state judiciary is nominated by the executive branch and approved by the leg-
islature for varying, but fixed, terms.

III. The Nature of a Legal Dispute
A legal dispute arises when someone claims to have been illegally harmed at the

hands of another. It is possible that the victim and the injurer can resolve their dispute
themselves, but sometimes they cannot. The person who feels injured may have a cause
of action, that is, a valid legal claim, against another person or organization. To assert
that action, he files a complaint and is, therefore, referred to as the plaintiff. The com-
plaint must state what has happened, why the plaintiff feels that he has been injured,
what area of law is involved, what statute or other law is relevant, and what relief he
wishes the court to give him. The complaint and the management of the subsequent as-
pects of the dispute are complicated matters; typically, private citizens retain the serv-
ices of a lawyer, who usually has far more experience in these matters than does the
citizen, to help them in all this.11

The person who is alleged to have injured the victim or plaintiff is called the
defendant and must answer the complaint. The answer does not go into detail about the

9 In 2007 Congress raised the minimum amount in controversy in diversity cases in order to alter the case-
load of the federal courts. Clearly, the greater the amount in controversy required, the fewer the number of
diversity cases that will be eligible for resolution by the federal courts.

10 But there is still an argument for maintaining federal jurisdiction in diversity cases where the benefits of a
decision may accrue to the people in one state and the costs fall on the people of another state.

11 Private citizens may, of course, represent themselves in a legal dispute. That is referred to as someone ap-
pearing pro se—that is, “for himself.” A common joke among lawyers is that a person who represents him-
self has a fool for a client.

III. The Nature of a Legal Dispute 63

matters at hand; rather, it is a short statement of what the defendant intends to argue in
detail if the matter goes to trial. Thus, the answer may say that the facts as alleged are
true but that even so, the defendant is not legally responsible for the plaintiff’s misfor-
tune. Figuratively, this form of answer says, “So what?” Or the answer may say that the
facts as alleged in the complaint are incorrect and that when the true facts are known,
the defendant will be seen to be innocent of any wrongdoing.

The dispute may well stop at this point. For example, the parties may decide not to
proceed to trial. They may drop the whole matter, or they may settle their dispute—that
is, reach a mutually satisfactory agreement between themselves. If the case is not set-
tled or dropped, a judge must make a determination based on the complaint and the an-
swer whether there is sufficient reason to proceed to trial. The judge may determine
that the plaintiff has failed to state a valid cause of action or that the defendant has
made a complete and convincing answer to the complaint. If so, she might dismiss the
complaint or enter summary judgment for the defendant. Usually, she will allow the
parties to proceed to trial. Parties may appeal from a summary judgment or a dismissal.

If the dispute proceeds to trial, a jury may be empaneled to determine the facts, or
else the case will be tried to a judge without a jury; this latter situation is called a bench
trial. Each side will develop evidence and testimony supporting its assertions, and then
the jury or judge will retire to determine who wins.12 The standard that the jury or judge
will use to make this determination is by a preponderance of the evidence. That means
that if the plaintiff’s arguments are more believable than the defendant’s, then the plain-
tiff wins; if the defendant’s are more believable, the defendant wins. Some people say that
the preponderance-of-the-evidence standard means that if the plaintiff’s story is 51 per-
cent believable, she wins. Notice that this standard, which is the routine standard in cases
involving private parties as litigants, is different from the one that is used in criminal pro-
ceedings. There, the prosecution must convince the jury that the defendant is guilty beyond
a reasonable doubt, a much more exacting standard than is preponderance of the evidence.

The courts can and have established other standards for prevailing in private law
disputes. For example, some jurisdictions have created a standard of clear and convinc-
ing evidence for some aspects of a civil case, such as the award of punitive damages.
No one can be certain exactly what that standard entails, but it is certainly more de-
manding than the preponderance-of-the-evidence standard and less demanding than the
beyond-a-reasonable-doubt standard of criminal law.

The jury returns with a verdict, which says, simply, which party wins. But the ver-
dict is not the end of the matter. The judge must enter judgment on the verdict. It is the
judgment, not the verdict, that is the controlling action of the court. Most of the time
the judge issues a judgment that follows exactly the jury verdict. But in a few rare cases
the judge decides that the jury got the matter entirely wrong and enters a judgment non
obstante verdicto or j.n.o.v. (judgment notwithstanding the verdict), holding the exact
opposite of what the jury decided.

12 Even after the trial has begun but before the judge or jury returns with a verdict, the parties are free to set-
tle the case. There are even examples—about which we have a question in Chapter 11—regarding situa-
tions in which the plaintiff has secretly settled with one of multiple defendants but allows the trial to go
forward to a conclusion.

64 C H A P T E R 3 A Brief Introduction to Law and Legal Institutions

In a civil dispute, either party, winner or loser, may appeal the court’s decision. The
winner may appeal because he feels that he has not received everything to which he is en-
titled; the loser may appeal for the obvious reason that he thinks that he ought to have won.
Interestingly, the ground for the appeal must be that the court below made a mistake about
the relevant law, including the relevant general principles that the court applied and the
procedures that were used in court, but not about the facts. For instance, the appellant (the
party filing the appeal) may allege that the judge gave the jury improper instructions about
what the relevant law was, or about what facts they could and could not consider, or that
the judge improperly excluded some evidence or testimony from the jury’s consideration.

At the appellate level there will be no new evidence or facts introduced. The appel-
late court takes the facts as developed in the trial court as given. The only people to ap-
pear before the appellate panel will be the attorneys for the appellant and appellee. The
attorneys will submit written briefs to the appellate panel and then appear before the panel
for oral argument, during which they may receive very close questioning on the matters
at hand. There may be additional briefs submitted by parties who are called amici curiae
(friends of the court); these parties are not directly involved in the legal dispute but feel
that the legal issue involved touches their interests sufficiently that they would like the
court to consider their arguments in addition to those of the appellant and appellee.

The appellate panel retires to consider the matter and later issues its opinion. The
judges may be in unanimous agreement and issue only one opinion. However, there
may be a split in the panel, and that split may result in multiple opinions: a majority
and a minority or dissenting opinions. The appellate panel may affirm the lower court’s
judgment or reverse that judgment. In some instances, the panel remands the matter
(that is, sends it back) to the lower court for specific corrective action, such as a recal-
culation of the damages owed to the plaintiff.

IV. How Legal Rules Evolve
We now consider a sequence of cases in order to apply the preceding ideas and

show how law evolves. The three cases come from England and concern tort law,
which covers accidents.

BUTTERFIELD V. FORRESTER, 11 EAST 60 (K.B., 1809)13

This was an action on the case14 for obstructing a highway, by means of which obstruc-
tion the plaintiff, who was riding along the road, was thrown down with his horse, and
injured, etc. At the trial before Bayley, J.,15 at Derby, it appeared that the defendant, for
the purpose of making some repairs to his house, which was close by the roadside at

13 Our selection and discussion of these cases owes a great debt to the stimulating lectures given by Professor
Robert Summers to the Fifth Legal Institute for Economists.

14 The phrase “action on the case” refers to an old legal category of dispute. Simply read it as “dispute.”
15 “J.” means “Judge” or “Justice” and, by tradition, opinions are headed by the last name of the judge or jus-

tice who wrote the opinion.

IV. How Legal Rules Evolve 65

one end of the town, had put up a pole across part of the road, a free passage being
left by another branch or street in the same direction. That the plaintiff left a public
house [a tavern] not far distant from the place in question at 8 o’clock in the evening in
August, when they were just beginning to light candles, but while there was light
enough left to discern the obstruction at one hundred yards distance; and the witness
who proved this, said that if the plaintiff had not been riding very hard, he might have
observed and avoided it; the plaintiff, however, who was riding violently, did not ob-
serve it, but rode against it, and fell with his horse and was much hurt in consequence
of the accident; and there was no evidence of his being intoxicated at the time. On this
evidence, Bayley, J., directed the jury, that if a person riding with reasonable and ordi-
nary care could have seen and avoided the obstruction; and if they were satisfied that
the plaintiff was riding along the street extremely hard, and without ordinary care, they
should find a verdict for the defendant, which they accordingly did.

QUESTION 3.1:

a. Who is the plaintiff? What is he asking the court to do?
b. Is there a statute involved in this dispute?
c. Who won?
d. Was the jury asked to determine fact or law? How was the law stated?

When this case was tried, English law accepted the principle that a defendant
whose negligence caused the plaintiff’s injury would be held liable. Consequently, the
judge instructed the jury that the defendant should be held liable if he could have
avoided the accident by taking “reasonable” care. This case presented a novel issue:
Suppose that the defendant was negligent, but further suppose that the victim was also
negligent. Should the defendant still be held liable for the victim’s losses? An excerpt
from the opinion of the judge in this appeal follows.

LORD ELLENBOROUGH, C.J.

A party is not to cast himself upon an obstruction which had been made by the fault
of another, and avail himself of it, if he does not himself use common and ordinary
caution to be in the right. In case of persons riding upon what is considered to be the
wrong side of the road, that would not authorize another purposely to ride up against
them. One person being in fault will not dispense with another’s using ordinary care
for himself. Two things must concur to support this action: an obstruction in the road
by the fault of the defendant, and no want of ordinary care to avoid it on the part of
the plaintiff. [C]ontributory negligence is a complete bar to recovery.

QUESTION 3.2:

a. Who appealed the judgment?
b. Who won the appeal?
c. What is the judge’s holding?

66 C H A P T E R 3 A Brief Introduction to Law and Legal Institutions

When precedent does not provide a clear rule for resolving a dispute, the judges
must create such a rule. Novel disputes are the occasion for altering the law made by
judges. Lord Ellenborough created a new precedent in this case. How broad is the new
precedent? Under a narrow interpretation, the judge held that riders of horses cannot
recover money damages for their injuries from a negligent defendant if they do not ride
with ordinary care, and this lack of care contributes to the accident. This narrow inter-
pretation says that the rule applies only to accidents like this one. Indeed, Lord
Ellenborough’s example of a horseman riding on the wrong side of the road into an-
other horseman riding on the correct side would seem to support this narrow interpreta-
tion. But a broader interpretation of the court’s holding is possible, and did, in fact,
come to be the common interpretation. Under a broad interpretation of the holding,
Lord Ellenborough held that no plaintiffs can recover when their own negligence con-
tributes to their injury (even if the defendant was negligent). This was new law.

About 30 years later, another novel case arose involving similar facts.

DAVIES V. MANN, 10 M.&W. 545 (EX., 1842)16

At the trial, before ERSKINE, J., it appeared that the plaintiff, having fettered the fore-
feet of an ass belonging to him, turned it into a public highway, and at the same time
in question the ass was grazing on the off side of a road about eight yards wide, when
the defendant’s wagon, with a team of three horses, coming down a slight descent, at
what the witness termed a smartish pace, ran against the ass, knocked it down, and the
wheels passing over it, it died soon after. . . . The learned judge told the jury, that . . . if
they thought that the accident might have been avoided by the exercise of ordinary

16 The traditional English court system that took shape in the late twelfth century and prevailed until the late
nineteenth century consisted of three common law courts and a court of equity. The first of the common
law courts was the Court of Common Pleas. The members of that court were called “Justices” and were
presided over by the Chief Justice. The court originally concentrated on civil disputes concerning land but
came to consider a wider range of civil disputes. The Court of King’s Bench, the second common law
court, was originally a criminal court but over time became a court of review over the civil issues appealed
from the Court of Common Pleas. The third common law court was the Court of Exchequer of Pleas or,
more simply, the Court of Exchequer. The Exchequer was the King’s treasury. This court originally heard
disputes arising from tax liability and other matters concerning the King’s revenues. By the late sixteenth
century, the Court of Exchequer had extended its jurisdiction to cover nearly all civil disputes. Members of
that court, in which the appeal in Davies v. Mann was heard, were called “Baron,” abbreviated “B.,” and
were presided over by the Chief Baron, abbreviated “C.B.”

The equity court was the Court of Chancery, so called because it was presided over by the Chancellor,
the most important member of the King’s Council. England established this court by the late fifteenth cen-
tury as a separate court specializing in the dispensing of a more flexible kind of justice than that available in
the so-called “law” courts, especially with respect to remedies. There is, therefore, a great historical and sub-
stantive difference between the courts of law and the court of equity. One of the most important of those dif-
ferences has to do with the types of remedies available to a successful plaintiff. Roughly speaking, a court of
law would award only compensatory money damages—an amount that would compensate the plaintiff for
his injury. A court of equity would possibly do more than that if the plaintiff could demonstrate that his in-
juries were such that a payment of money damages would inevitably undercompensate him.

(continued )

IV. How Legal Rules Evolve 67

care on the part of the driver, to find for the plaintiff. The jury found their verdict for
the plaintiff. . . .

Godson now moved for a new trial, on the ground of misdirection. [That is, the de-
fendant’s lawyer appealed the judgment on the ground that the judge in the trial court
had incorrectly instructed the jury on the law to be applied to the facts in this case.]
The act of the plaintiff in turning the donkey into the public highway was an illegal
one, and, as the injury arose principally from that act, the plaintiff was not entitled to
compensation for that injury which, but for his own unlawful act would never have
occurred. . . . The principle of law, as deducible from the cases is, that where an acci-
dent is the result of faults on both sides neither party can maintain an action. Thus, in
Butterfield v. Forrester, 11 East 60, it was held that one who is injured by an obstruc-
tion on a highway, against which he fell, cannot maintain an action, if it appear that
he was riding with great violence and want of ordinary care, without which he might
have seen and avoided the obstruction.

LORD ABINGER, C.B. [A]s the defendant might, by proper care, have avoided injur-
ing the animal, and did not, he is liable for the consequences of his negligence,
though the animal may have been improperly there.

PARKE, B. [T]he negligence which is to preclude a plaintiff from recovering in an ac-
tion of this nature, must be such as that he could, by ordinary care, have avoided the
consequences of the defendant’s negligence. [A]lthough the ass may have been
wrongfully there, still the defendant was bound to go along the road at such a pace
as would be likely to prevent mischief. Were this not so, a man might justify the driv-
ing over goods left on a public highway, or even over a man lying asleep there, or the
purposely running against a carriage going on the wrong side of the road. . . .

[New trial denied.]

QUESTION 3.3:

a. Who appealed the judgment?
b. Who won the appeal?
c. What is the judge’s holding? Actually, there are three opinions. Are they in accord?

A plaintiff has suffered a loss: His donkey was killed, allegedly because the defen-
dant was driving a wagon too quickly for the conditions on the road. However, the
plaintiff himself was negligent for having left his donkey unattended, although fettered,
beside a public road. Strictly following the rule in Butterfield, the plaintiff’s fault or
negligence contributed to his losses and thus should bar his recovery. That is precisely
what Mann’s lawyer argued in appealing the judgment for the plaintiff in the
lower court. But at the trial, the court believed that the facts in Davies v. Mann were

In the Judicature Act of 1873 and the Supreme Court of Judicature (Consolidation) Act of 1925, the
British Parliament replaced all of these courts—and the distinction between law and equity—with a greatly
simplified structure that drew no distinction between common law and equity.

As we shall see in Chapter 4, these dusty historical matters are relevant to one of the most famous ex-
amples of law and economics: the Calabresi and Melamed argument regarding the most efficient method of
protecting a legal entitlement.

68 C H A P T E R 3 A Brief Introduction to Law and Legal Institutions

distinguishable from those in earlier cases in which a contributorily negligent plaintiff
was not allowed to recover from a negligent defendant. There appear to be two reasons
for excusing the plaintiff’s negligence in Lord Abinger’s and Baron Parke’s opinions.
First, there is the element of time. Although the plaintiff was negligent in leaving his
donkey unattended on the public highway, the defendant’s negligence came afterward.
And if the defendant had not been driving recklessly, he would have had time to avoid
the donkey by stopping or swerving—even though the donkey ought not to have been
unattended where he was. Apparently, the defendant’s negligence came afterward and
controlled the outcome. This doctrine has come to be known as the “last clear chance”
rule: If both parties to an accident are negligent, the party who had the last clear chance
to avoid the accident will be held responsible for losses arising from the accident.

The second argument for excusing the plaintiff’s negligence is to encourage pre-
cautions in the future by people situated like the defendant. Again, Baron Parke puts
the point nicely, “[A]lthough the ass may have been wrongfully there, still the defen-
dant was bound to go along the road at such a pace as would be likely to prevent mis-
chief. Were this not so, a man might justify the driving over goods left on a public
highway, or even over a man lying asleep there, or the purposely running against a car-
riage going on the wrong side of the road.” This interpretation of the law suggests that
rules should create incentives for avoiding accidents.

Notice that Davies v. Mann changes the law handed down in Butterfield v.
Forrester. The blanket rule from the earlier case—contributory negligence is a com-
plete bar to recovery—was amended by judges who faced a new situation. We may say
that after Davies v. Mann the legal rule became:

Contributory negligence is a complete bar to recovery unless the defendant had the last
clear chance to avoid the accident and did not take that chance.

The “last clear chance” doctrine was quickly adopted throughout the common law
world.17

17 But that is not the end of the story of contributory negligence and “last clear chance.” For a fascinating
further episode, see British Columbia Electric Rail Co., Ltd. v. Loach, [1916] 1 A.C. 719. In brief, here is
what was at dispute in that case: Benjamin Sands was driving a horse-drawn wagon and talking with a
friend. Not paying attention to his surroundings, he pulled onto the train tracks and stopped. He looked up
to see a train coming. The train’s engineer applied the brakes as soon as he saw Sands and his wagon on
the tracks. Unfortunately, the brakes, unknown to the engineer, were defective and failed to stop the train
before it ran into and killed Mr. Sands. Loach, the executor of Sands’s estate, sued the British Columbia
Electric Rail Co. on a theory of negligence. The railroad claimed, following Butterfield, that it should not
be held liable because Sands was contributorily negligent. Loach answered that the railroad had, following
Davies, the last clear chance to avoid the injury and did not take that chance. The railroad claimed that it
had not, in fact, had the last clear chance because its brakes were defective. (Everyone agreed that the train
would have stopped in time had the brakes been in good working order and that the railroad should have
checked the brakes before leaving the roundhouse that morning.) The holding was that the railroad should
be held liable: To hold otherwise would, the court said, create an incentive not to maintain one’s train (or
car or wagon or other device) in good working order.

Suggested Readings 69

Conclusion
To summarize, we compared the two great legal traditions—the civil law and the

common law. We examined the hierarchical structure of U.S. courts. We saw some of
the general characteristics of a legal dispute: a plaintiff who alleges that he or she has
been wronged by a defendant and seeks the courts’ help in getting relief. We learned
some methods that judges use to resolve novel issues. Finally, we looked at the evolu-
tion of the doctrine of contributory negligence as developed by courts. This chapter
provides a brief, selective introduction to some of the basic facts about law, which we
analyze using economics in the rest of the book.

Suggested Readings

BERMAN, HAROLD J., & WILLIAM R. GREINER, THE NATURE AND FUNCTIONS OF LAW

(4th ed. 1980).

CARDOZO, BENJAMIN, THE NATURE OF THE JUDICIAL PROCESS (1921).

EISENBERG, MELVIN A., THE NATURE OF THE COMMON LAW (1989).

FRANKLIN, MARC A., THE BIOGRAPHY OF A LEGAL DISPUTE: AN INTRODUCTION TO AMERICAN

CIVIL PROCEDURE (1968).

LEVI, EDWARD H., AN INTRODUCTION TO LEGAL REASONING (1949).

MERRYMAN, JOHN H., THE CIVIL LAW TRADITION: AN INTRODUCTION TO THE LEGAL SYSTEMS OF

WESTERN EUROPE AND LATIN AMERICA (2nd ed. 1985).

There is nothing which so generally strikes the imagination and engages the affections
of mankind, as the right of property; or that sole and despotic dominion which one
man claims and exercises over the external things of the world, in total
exclusion of the right of any other individual in the universe.

WILLIAM BLACKSTONE,
COMMENTARIES ON THE LAWS OF ENGLAND, BK. II, CH. 1, P. 2 (1765–69)

In the African tribe called the Barotse, “property law defines not so much the rights of
persons over things as the obligations owed between persons in respect of things.”

MAX GLUCKMAN,
IDEAS IN BAROTSE JURISPRUDENCE 171 (1965)

[T]he theory of the Communists may be summed up in a single sentence: Abolition of
private property.

KARL MARX & FRIEDRICH ENGELS,
THE COMMUNIST MANIFESTO (1848)

THE LAW OF property supplies the legal framework for allocating resources and
distributing wealth. As the contrasting quotes above indicate, people and soci-
eties disagree sharply about how to allocate resources and distribute wealth.

Blackstone viewed property as providing its owner with complete control over re-
sources, and he regarded this freedom to control material things as “the guardian of
every other right.” Gluckman found that property in an African tribe called the Barotse
conveyed to its owner responsibility, not freedom. For example, the Barotse hold rich
persons responsible for contributing to the prosperity of their kin. Finally, Marx and
Engels regarded property as the institution by which the few enslaved the many.

Classical philosophers try to resolve these deep disputes over social organization by
explaining what property really is. The appendix to this chapter provides some examples
of philosophical theories, such as the theory that property is an expectation (Bentham),
the object of fair distribution (Aristotle), a means of self-expression (Hegel), or the foun-
dation of liberty in community life (Burke). Instead of trying to explain what property
really is, an economic theory tries to predict the effects of alternative forms of ownership,
especially the effects on efficiency and distribution. We shall make such predictions about
alternative property rules and institutions.

70

4 An Economic Theory
of Property

C H A P T E R 4 An Economic Theory of Property 71

Here are some examples of problems addressed by property rules and institutions
that we will analyze:

Example 1: “This morning in a remote meadow in Wyoming, a mule
was born. To whom does that mule belong?”1 Does the mule belong to (1) the
owner of the mule’s mother, (2) the lumber company that has leased the land on
which the mule was grazing, or (3) the federal government because the property
is a national forest?

Example 2: Orbitcom, Inc., spent $125 million designing, launching,
and maintaining a satellite for the transmission of business data between Europe
and the United States. The satellite is positioned in a geosynchronous orbit
25 miles above the Atlantic Ocean.2 Recently a natural resource-monitoring satel-
lite belonging to the Windsong Corporation has strayed so close to Orbitcom’s
satellite that the company’s transmissions between Europe and the United States
have become unreliable. As a result, Orbitcom has lost customers and has sued
Windsong for trespassing on Orbitcom’s right to its geosynchronous satellite orbit.

Example 3: Foster inspects a house under construction in a new subdivi-
sion on the north side of town and decides to buy it. The day after she moves in,
the wind shifts and begins to blow from the north. She smells a powerful stench.
On inquiring, she learns that a large cattle feedlot is located north of the subdivi-
sion, just over the ridge, and, to make matters worse, the owner of this old busi-
ness plans to expand it. Foster joins other property owners in an action to shut
down the feedlot.

Example 4: Bloggs inherits the remnant of a farm from his father, most
of which has already been sold for a housing development. The remaining
acreage, which his father called “The Swamp,” is currently used for fishing and
duck hunting, but Bloggs decides to drain and develop it as a residential area.
However, scientists at the local community college have determined that Bloggs’s
property is part of the wetlands that nourish local streams and the fish in the
town’s river. The town council, hearing of Bloggs’s plans, passes an ordinance for-
bidding the draining of wetlands. Bloggs sues for the right to develop his prop-
erty, or, failing that, for an order compelling the town to buy the property from
him at the price that would prevail if development were allowed.

Example 5: A county ordinance requires houses to be set back 5 feet
from the property line. Joe Potatoes buys some heavily wooded land in an unde-
veloped area and builds a house on it. Ten years later Fred Parsley, who owns the
adjoining lot, has his land surveyed and discovers that Potatoes’s house extends
2 feet over the property line onto Parsley’s property. Potatoes offers to compen-
sate Parsley for the trespass, but Parsley rejects the offer and sues to have
Potatoes relocate the house in conformity with the ordinance.

1 This remarkable question is how Professor John Cribbet, one of the leading scholars of property law,
opened his first lecture on property to first-year law students at the University of Illinois College of Law.

2 A geosynchronous orbit means that the satellite is traveling around the Earth at exactly the same speed at
which the Earth is turning so that the satellite appears to remain stationary above a point on the Earth’s
surface.

72 C H A P T E R 4 An Economic Theory of Property

These five examples capture some of the most fundamental questions that any
system of property law must answer. The first and second examples ask how property
rights are initially assigned. Orbitcom apparently bases its ownership claim on having
placed a satellite in the orbit in dispute before anyone else. This claim appeals to a
legal principle called the rule of first possession, according to which the first party to
use an unowned resource acquires a claim to it. (How might this rule apply to the mule
born on the remote Wyoming meadow?) The general issue raised here is, “How does
a person acquire ownership of something?”

The second example also asks what kinds of things may be privately owned.
Orbitcom asserts that a satellite orbit may be privately owned like land or a musical
composition, whereas Windsong feels, perhaps, that orbits should be commonly
owned by all and open to all on the same terms, like the high seas. Economics has a
lot to say about the consequences of resources being privately owned, commonly
owned, or unowned.

The third example concerns a problem sometimes known as “incompatible uses.”
May one property owner create a stench on his own property that offends his neigh-
bors? In general, the law tries to prevent property owners from interfering with each
other, but in this example, as in many other cases, there is a trade-off between compet-
ing activities. Is the cattle feedlot interfering with the homeowner by creating the
stench, or is the homeowner interfering with the feedlot by moving nearby and seeking
to shut it down? The legal outcome turns in part on whether the stench constitutes a
“nuisance” as defined by law. Economics has a lot to say about this determination.

The fourth example, like the third, raises the question, “What may owners legiti-
mately do with their property?” The difference is that Example 3 concerns a dispute
between private owners and Example 4 concerns a dispute between a private owner
and a government. The specific question in Example 4 is whether a property owner
can develop his land according to his own wishes or must conform to restrictions on
development imposed by a local government. The general question concerns the ex-
tent to which government may constrain a private owner’s use of her property. We will
show that economics has a lot to say about government’s regulating and taking private
property.

In the last example, one property owner has encroached on the land of another, but
that encroachment has gone undetected and without apparent harm for many years. The
question raised by this example concerns the remedy for trespass. Should the owner be
denied a remedy because the trespass has persisted for so long? Alternatively, should
the court award compensatory damages to the owner? Or should the court enjoin the
trespasser and force him to move his house? As we shall see, economics predicts the
effects of various remedies and thus provides a powerful tool for choosing the best one.
We shall also see why courts prefer the remedy of issuing an order called an “injunction”
to stop trespassing or otherwise interfering with the property owner.

The examples raise these four fundamental questions of property law:

1. How are ownership rights established?
2. What can be privately owned?
3. What may owners do with their property?
4. What are the remedies for the violation of property rights?

I. The Legal Concept of Property 73

In the next two chapters we shall be using economics to answer these questions.
Traditional legal scholarship on property law is notoriously weak in its use of the-
ory, at least in comparison to contracts and torts.3 This fact contributes to the feel-
ing of many students that the common law of property is diffuse and unorganized.
Through economics it is possible to give the subject more coherence and order. In
this chapter we concentrate on developing fundamental tools for the economic
analysis of property: bargaining theory, public goods theory, and the theory of
externalities. In the next chapter we apply these tools to a large number of property
laws and institutions.

I. The Legal Concept of Property
From a legal viewpoint, property is a bundle of rights. These rights describe what

people may and may not do with the resources they own: the extent to which they may
possess, use, develop, improve, transform, consume, deplete, destroy, sell, donate, be-
queath, transfer, mortgage, lease, loan, or exclude others from their property. These
rights are not immutable; they may, for example, change from one generation to an-
other. But at any point in time, they constitute the detailed answer of the law to the four
fundamental questions of property law listed above.

Three facts about the bundle of legal rights constituting ownership are fundamen-
tal to our later understanding of property. First, these rights are impersonal in the sense
that they attach to property, not persons. Any person who owns the property has the
rights. In this respect, property rights are different from contract rights. Contract rights
are personal in the sense that one person owes something to another person. Second,
the owner is free to exercise the rights over his or her property, by which we mean that
no law forbids or requires the owner to exercise those rights. In our example at the
beginning of the chapter, Parsley can farm his land or leave it fallow, and the law is
indifferent as to which he chooses to do. Third, others are forbidden to interfere with
the owner’s exercise of his rights. If others interfere, the court will enjoin them to
stop—the court will issue an order that they must stop interfering on pain of punish-
ment for contempt of court. Thus, if Parsley decides to farm his land, Potatoes can-
not put stones in the way of the plow. This protection is needed against two types of
interlopers—private persons and the government.

The legal conception of property is, then, that of a bundle of rights over resources
that the owner is free to exercise and whose exercise is protected from interference by
others. Thus, property creates a zone of privacy in which owners can exercise their will
over things without being answerable to others, as stressed in the preceding quote from

3 In contracts and torts there was a classical theory that dominated American law at the beginning of the
twentieth century. The introductory chapters on contracts and torts describe these classical theories. There
was, however, no classical theory of property of comparable coherence, detail, or stature. Instead there is a
long philosophical tradition of analyzing the institution of property at a very abstract level. Some of these
philosophical theories of property are described in the appendix to this chapter.

74 C H A P T E R 4 An Economic Theory of Property

Blackstone. These facts are sometimes summarized by saying that property gives
owners liberty over things.

This general definition of property is compatible with many different theories
of what particular rights are to be included in the protected bundle and of how to
protect those rights. It is also consistent with different accounts of the responsibili-
ties that a person assumes by becoming an owner. The law has tended to look be-
yond itself to philosophy for help in deciding which rights to include in the bundle
of property rights.

In the approach taken in this chapter, we focus on how alternative bundles of rights
create incentives to use resources efficiently. An efficient use of resources maximizes
the wealth of a nation. We begin by showing how the right to exchange property con-
tributes to the nation’s wealth.

II. Bargaining Theory4

To develop an economic theory of property, we must first develop the eco-
nomic theory of bargaining games. At first you may not see the relevance of this
theory to property law, but later you will recognize that it is the very foundation of
the economic theory of property. The elements of bargaining theory can be devel-
oped through an example of a familiar exchange—selling a used car. Consider
these facts:

Adam, who lives in a small town, has a 1957 Chevy convertible in good repair. The
pleasure of owning and driving the car is worth $3000 to Adam. Blair, who has been
coveting the car for years, inherits $5000 and decides to try to buy the car from Adam.
After inspecting the car, Blair decides that the pleasure of owning and driving it is
worth $4000 to her.

According to these facts, an agreement to sell will enable the car to pass from
Adam, who values it at $3000, to Blair, who values it at $4000. The potential seller
values the car less than the potential buyer, so there is scope for a bargain.
Assuming that exchanges are voluntary, Adam will not accept less than $3000 for
the car, and Blair will not pay more than $4000, so the sale price will have to be
somewhere in between. A reasonable sale price would be $3500, which splits the
difference.

The logic of the situation can be clarified by restating the facts in the language of
game theory. The parties to the kind of game represented by this example can both
benefit from cooperating with each other. To be specific, they can move a resource
(the car) from someone who values it less (Adam) to someone who values it more
(Blair). Moving the resource in this case from Adam, who values it at $3000, to Blair,

4 Bargaining theory is a form of game theory. See the section on game theory in Chapter 2 for some useful
background information.

II. Bargaining Theory 75

who values it at $4000, will create $1000 in value. The cooperative surplus is the
name for the value created by moving the resource to a more valuable use. Of course,
the share of this surplus that each party receives depends on the price at which the car
is sold. If the price is set at $3500, each will enjoy an equal share of the value created
by the exchange, or $500. If the price is set at $3800, the value will be divided un-
equally, with Adam enjoying 4/5 or $800, and Blair enjoying 1/5 or $200. Or if the
price is set at $3200, Adam will enjoy $200 or 1/5 of the value created, whereas Blair
will enjoy $800 or 4/5.

The parties typically bargain with each other over the price. In the course of nego-
tiating, the parties may assert facts (“The motor is mechanically perfect. . . .”), appeal to
norms (“$3700 is an unfair price. . . .”), threaten (“I won’t take less than $3500. . . .”),
and so forth. These are the tools used in the art of bargaining. The fact that the parties
can negotiate is an advantage of bargaining or cooperative games relative to other
games (called noncooperative games), such as the famous Prisoner’s Dilemma, which
we examined in Chapter 2. Even when negotiation is possible, however, there is no
guarantee that it will succeed. If the negotiations break down and the parties fail to co-
operate, their attempt to shift resources to a more valuable use will fail, and they will
not create value. Thus, the obstacle to creating value in a bargaining game is that the
parties must agree on how to divide it. Value will be divided between them at a rate
determined by the price at which the car is sold. Agreement about the car’s price
marks successful negotiations, whereas disagreement marks a failure in the bargain-
ing process.

To apply game theory to this example, let us characterize the possible outcomes
as a cooperative solution and a noncooperative solution. The cooperative solution is
the one in which Adam and Blair reach agreement over a price and succeed in ex-
changing the car for money. The noncooperative solution is the one in which they fail
to agree on a price and fail to exchange the car for money. To analyze the logic of
bargaining, we must first consider the consequences of noncooperation. If the parties
fail to cooperate, they will each achieve some level of well-being on their own. Adam
will keep the car and use it, which is worth $3000 to him. Blair will keep her
money—$5000—or spend it on something other than the car. For simplicity, assume
that the value she places on this use of her money is its face value, specifically,
$5000. Thus, the payoffs to the parties in the noncooperative solution, called their
threat values, are $3000 for Adam (the value to him of keeping the car) and $5000 to
Blair (the amount of her cash). The total value of the noncooperative solution is
$3000 + $5000 = $8000.

In contrast, the cooperative solution is for Adam to sell the car to Blair. Through
cooperation, Blair will own the car, which is worth $4000 to her, and in addition, the
two parties will each end up with a share of Blair’s $5000. For example, Adam might
accept $3500 in exchange for the convertible. Blair then has the car, worth $4000
to her, and $1500 of her $5000. Thus, the value of the cooperative solution is $4000
(the value of the car to Blair) + $1500 (the amount that Blair retains of her original
$5000) + $3500 (the amount received by Adam for the car) = $9000. The surplus
from cooperation is the difference in value between cooperation and noncooperation:
$9000 – $8000 = $1000.

76 C H A P T E R 4 An Economic Theory of Property

In any voluntary agreement, each player must receive at least the threat value
or there is no advantage to cooperating. A reasonable solution to the bargaining prob-
lem is for each player to receive the threat value plus an equal share of the cooperative
surplus: specifically, $3500 for Adam and $5500 for Blair.5 To accomplish the division,
Blair should pay Adam $3500 for the car. This leaves Adam with $3500 in cash and no
car, and leaves Blair with a car worth $4000 to her and $1500 in cash.

QUESTION 4.1: Suppose Adam receives a bid of $3200 from a third party
named Clair. How does Clair’s bid change the threat values, the surplus from
cooperation, and the reasonable solution?

We have explained that the process of bargaining can be divided into three steps:
establishing the threat values, determining the cooperative surplus, and agreeing on
terms for distributing the surplus from cooperation. These steps will be used in the next
section to understand the origins of the institution of property.

Before proceeding, however, we must warn you about a common problem in the
economic analysis of law. In general, economic analysis sometimes uses morally or
legally insensitive language to describe useful concepts. “Threat value” is an example.
“Threat” connotes “coercion” and coercion often voids a contract or constitutes a tort
or crime. If you are speaking to a judge or juror, do not say “threat” unless you intend
to connote illegality. This is one example where you will need to substitute other terms
for economic language. Refusing to cooperate with the other party and going alone is
usually legal. Instead of “threat value” you might try the phrase “fallback position” or
“go-it-alone value.”

III. The Origins of the Institution of Property:
A Thought Experiment

The bargaining model shows how cooperation can create a surplus that benefits
everyone. This type of reasoning can be used to perform a thought experiment that is
helpful in understanding the origins of property.

5 Economists have long struggled with the fact that self-interested rationality alone does not seem sufficient
to determine the distribution of the cooperative surplus. That is why we use the term reasonable solution,
which invokes social norms, rather than rational solution. To see the difference, consider this rational ac-
count of the division of the cooperative surplus. Suppose that somehow Adam knows that the cooperative
surplus resulting from an agreement between Blair and him is $1000. Being perfectly rational, he says to
Blair that he will sell the car to her for $3995. And, further, he explains to her why she should accept that
price, even though it gives Adam $995 of the cooperative surplus and Blair, $5: “If you do not accept that
price, I will not do business with you, in which case you will realize $0 worth of cooperative surplus. At the
$3995 price, you get $5 of the cooperative surplus and that surely is better than nothing.” Leaving aside all
the strategic reasons that Blair might balk at this (Will Adam really walk away if she refuses?), this division
of the cooperative surplus is perfectly rational, but it may not be reasonable. In fact, carefully controlled
experiments have demonstrated that most people would not accept Adam’s offer, rational though it be.

III. The Origins of the Institution of Property: A Thought Experiment 77

A Civil Dispute as a Bargaining Game

Because trials are costly, both parties can usually gain by settling out of court. That is why so
few disputes ever come to trial. As we will see in Chapter 10, the best current estimate is that
approximately 5 percent of all disputes that reach the stage of filing a legal complaint in the
United States actually result in litigation. Here is a problem in which you must apply bargain-
ing theory to a civil dispute:

FACTS: Arthur alleges that Betty borrowed a valuable kettle and broke it, so
he sues to recover its value, which is $300. The facts are very confusing. Betty con-
tends that she did not borrow a kettle from Arthur; even if it is proved that she bor-
rowed a kettle from Arthur, she contends it is not broken; even if it is proved that
she borrowed a kettle from Arthur and that it is broken, she contends that she did
not break it.

Assume that because the facts in the case are so unclear, Arthur and Betty in-
dependently believe that the chances of either side’s winning in court are an even
50 percent. Further assume that litigation in small claims court will cost each party
$50 and that the costs of settling out of court are nil. So, cooperation in this case is
a matter of settling out of court and saving the cost of a trial. Noncooperation in this
case means trying the dispute.

QUESTIONS:
a. What is Arthur’s threat value?
b. What is Betty’s threat value?
c. If Arthur and Betty cooperate together in settling their disagreement, what is the

net cost of resolving the dispute?
d. What is the cooperative surplus?
e. A reasonable settlement would be for Betty to pay Arthur _____.
f. Suppose that instead of both sides believing that there is an even chance of win-

ning, both sides are optimistic. Specifically, Arthur thinks that he will win with prob-
ability 2/3, and Betty thinks that she will win with probability 2/3.
1. What is Arthur’s putative threat value (what he believes he can secure on his own

without Betty’s cooperation)?
2. What is Betty’s putative threat value (what she believes she can secure on her

own without Arthur’s cooperation)?
3. The putative cooperative surplus equals _____.
4. Describe the obstacle to settlement in a few words.

Let us imagine a simplified world in which there are people, land, farm tools, and
weapons but no courts and no police. In this imaginary world, government does not
vindicate and protect the rights to property asserted by the people who live on the land.
Individuals, families, or alliances of families enforce property rights to the extent that
they defend their land holdings. People must decide how many resources to devote to
defending their property claims. Rational people allocate their limited resources so that,

78 C H A P T E R 4 An Economic Theory of Property

as we saw in Chapter 2, the marginal cost of defending land is just equal to the mar-
ginal benefit. This means that at the margin, the value of the resources used for military
ends (the marginal benefit) equals their value when used for productive ends, such as
raising crops and livestock (marginal [opportunity] cost). For example, the occupants
are rational if allocating a little more time to patrolling the perimeter of the property
preserves as much additional wealth for the defenders as they would enjoy by allocat-
ing a little more time to raising crops. The same statement could be made about allo-
cating land between crops and fortifications, or about beating metal into swords or
plowshares.

These facts describe a world in which farming and fighting are individually
rational. But are they socially efficient? In Chapter 2 we offered the following defini-
tion of inefficient production: The same (or fewer) inputs could be used to produce a
greater (or the same) total output. Can some mechanism be found that uses fewer
resources to achieve the same level of protection for property claims? One possible
mechanism is law. Suppose that the costs of operating this system of property rights
are less than the sum of all individual costs of private defense. Such a mechanism
would allow the transfer of resources from fighting to farming. For example, the
landowners might create a government to protect their property rights at lower cost
in individual taxes than each individual spends on fighting. The savings might come
from economies of scale in having one large army in the society to defend everyone,
rather than many small, privately financed armies.6 In other words, there may be a
natural monopoly on force.

We could imagine the parties bargaining together over the terms for establishing a
government to recognize and enforce their property rights. They are motivated by the
realization that there are economies of scale in protecting property. By reaching an
agreement to have one government backed by one army, everyone can enjoy greater
wealth and security. The bargain eventually reached by such negotiations is called the
social contract by philosophers because it establishes the basic terms for social life.7 It
would be rational for the parties negotiating the social contract to take account of other
rights of owners besides the right to exclude. Many of the rights that are currently in
the bundle called property could be considered, such as the right to use, transfer, and
transform. Indeed, many rights other than property rights could be a part of the social
contract, such as freedom of speech and freedom of religion, but they do not concern
us in this chapter.

6 Recall that economies of scale occur when the cost per unit (or average cost of production) declines as the
total amount of output increases. A production technology for which the unit costs are falling at every level
of production, even very large levels, is called a natural monopoly because one producer can sell at a lower
price than many smaller producers.

7 The social contract has usually been thought of as a logical construct, but some theorists have used it to
explain history. For example, it has been argued that feudalism in the Middle Ages corresponds roughly
to the conditions of our imaginary world. The economic factors that caused this system to be replaced in
some parts of Western Europe by a system of private property rights enforced by a central government are
discussed in DOUGLASS C. NORTH & ROBERT PAUL THOMAS, THE RISE OF THE WESTERN WORLD (1973).

III. The Origins of the Institution of Property: A Thought Experiment 79

The same bargaining model used to explain the sale of a secondhand car can be
applied to this thought experiment, in which a primitive society develops a system
of property rights. First, a description is given of what people would do in the absence
of civil government, when military strength alone established ownership claims. That
situation—called the state of nature—corresponds to the threat values of the noncooper-
ative solution, which prevails if the parties cannot agree. Second, a description is given
of the advantages of creating a government to recognize and enforce property rights.
Civil society, in which such a government exists, corresponds to the game’s cooperative
solution, which prevails if the parties can agree. The social surplus, defined as the differ-
ence between the total amount spent defending land in the state of nature and the total
cost of operating a property-rights system in civil society, corresponds to the coopera-
tive surplus in the game. Third, an agreement describes the methods for distributing the
advantages from cooperation. In the car example, this agreement arises from the price
that the buyer offers and the seller accepts. In the thought experiment, this agreement
arises from the social contract that includes the fundamental laws of property.

To see the parallel more clearly, imagine that our world consists of only two
people, A and B. In a state of nature, each one grows some corn, steals corn from
the other party, and defends against theft. Each of the parties has different levels of
skill at farming, stealing, and defending. Their payoffs in a state of nature are sum-
marized in Table 4.1. Taken together, A and B produce 200 units of corn, but it gets
reallocated by theft. For example, A steals 40 units of corn from B and loses 10
units of corn to B through theft. Notice that A ultimately enjoys 80 units of corn,
and B enjoys 120 units, after taking into account the gains and losses from theft.

Instead of persisting in a state of nature, A and B may decide to enter into a co-
operative agreement, recognize each other’s property rights, and adopt an enforce-
ment mechanism that puts an end to theft. Let us assume that cooperation will
enable them to devote more resources to farming and fewer resources to fighting, so
that total production will rise from 200 units to 300 units. One hundred units thus
constitutes the social or cooperative surplus. In civil society there will be a mecha-
nism for distributing the surplus from cooperation, such as government taxes and
subsidies. The parties must decide through bargaining how this is to be done. A rea-
sonable division of that surplus gives each party an equal share. So, in civil society,
each party receives half the cooperative surplus plus the individual net consumption

TABLE 4.1
The State of Nature

Farmer
Corn

Grown
Corn Gained

by Theft
Corn Lost

Through Theft
Net Corn

Consumption

A 50 40 210 80
B 150 10 240 120
Totals 200 50 250 200

80 C H A P T E R 4 An Economic Theory of Property

in the state of nature, which is each party’s threat value. These facts are summarized
in Table 4.2.

What is the meaning of this “thought experiment” concerning the origins of prop-
erty? Read literally, you might conclude that individuals or tribes acquire government
by meeting together and agreeing to create a system of law, including property rights.
This literal reading is bad history and bad anthropology. Instead of a contract, a system
of property law can begin with a military conquest, a rebellion against feudalism, or the
disintegration of communism. Instead of history, the thought experiment is really about
processes that go on all the time.

In a changing society, new forms of property arise continually. To illustrate, prop-
erty law for underground gas and the electromagnetic spectrum (radio and television
broadcasting) developed in the United States during the last century; and property law
for computer software, music, video, and other material on the Internet, and genetically
engineered forms of life developed in the last several decades. The need for a new form
of property law arises in situations corresponding to our thought experiment. For ex-
ample, like corn, digital music can be stolen. Without effective property law, people in-
vest a lot of resources in stealing that music or trying to prevent its theft. These efforts
redistribute music, rather than invent or manufacture it. Now the United States has
property law that prevents the stealing of digital music. The imposition of these laws
may have greatly stimulated the production of music. So, our thought experiment is re-
ally a parable about the incentive structure that motivates societies to continually create
property.

The first question that we posed about property law is, “How are property rights
established?” This is a question about how an owner acquires the legal right to prop-
erty. Our thought experiment answers the question, “Why are ownership rights estab-
lished?” This is a question about why a society creates property as a legal right. The
two questions are closely connected. Societies create property as a legal right to en-
courage production, discourage theft, and reduce the costs of protecting goods. Law
prescribes various ways that someone can acquire a property right, such as by finding
and purchasing land with natural gas beneath it, inventing a computer program, or dis-
covering sunken treasure.

We now turn to the elaboration of how bargaining theory can help the law pre-
scribe ways for the acquisition of property that also encourage production, or discour-
age theft, and reduce the costs of protecting goods.

TABLE 4.2
Civil Society

Farmer Threat Value Share of Surplus Net Corn Consumption

A 80 50 130
B 120 50 170
Totals 200 100 300

IV. An Economic Theory of Property 81

QUESTION 4.2:

a. Is the cooperative solution fair? Can the resulting inequality in civil society
be justified? To answer these questions, draw on your intuitive ideas of fair-
ness or, better still, a concept of fairness developed by a major philosopher
such as Hobbes, Locke, Rawls, or Aristotle.

b. Suppose that the bargaining process did not allow destructive threats, such
as the threat to steal. How might this restriction affect the distribution of the
surplus?

c. What is the difference between the principle, “To each according to his
threat value,” and this principle, “To each according to his productivity”?

IV. An Economic Theory of Property
The fact that the same theory of bargaining can be applied to selling a used car or

creating a civil society is proof of that theory’s generality and power. Indeed, bargaining
theory is so powerful that, as this section will show, it serves as the basis for an economic
theory of property and of property law. Let us briefly summarize where we are going.

By bargaining together, people frequently agree on the terms for interacting and
cooperating. But sometimes the terms for interacting and cooperating are imposed on
people from the outside—for example, by law. The terms are often more efficient when
people agree on them than when a lawmaker or conqueror imposes them. It follows that
law is unnecessary and undesirable where bargaining succeeds, and that law is neces-
sary and desirable where bargaining fails.

These propositions apply to the four questions about property that we asked above.
In certain circumstances we do not need property law to answer the four questions that
we posed at the beginning of this chapter. Rather, in those special circumstances, pri-
vate bargaining will establish what things are property, who has claims to that property,
what things an owner may and may not do with the property, and who may interfere
with an owner’s property. The special circumstances that define the limits of law are
specified in a remarkable proposition called the Coase Theorem. This theorem, to
which we now turn, helped to found the economic analysis of law and won its inventor
the Nobel Prize in economics.

A. The Coase Theorem8

Different commentators formulate the Coase Theorem differently. We will ex-
pound a simple version of the theorem and then acquaint you with some of the
commentary.

8 The theorem is discussed in Professor Ronald H. Coase’s The Problem of Social Cost, 3 J. LAW & ECON. 1
(1960). The article has been reprinted in numerous legal and economic anthologies, notably R. BERRING

ED., GREAT AMERICAN LAW REVIEWS (1984) (a compendium of the 22 “greatest” articles published in the
United States’ law reviews before 1965).

82 C H A P T E R 4 An Economic Theory of Property

Ranch

Farm

tilled

FIGURE 4.1

Consider the example of the rancher and the farmer as depicted in Figure 4.1.
A cattle rancher lives beside a farmer. The farmer grows corn on some of his land
and leaves some of it uncultivated. The rancher runs cattle over all of her land. The
boundary between the ranch and the farm is clear, but there is no fence. Thus, from
time to time the cattle wander onto the farmer’s property and damage the corn. The
damage could be reduced by building a fence, continually supervising the cattle,
keeping fewer cattle, or growing less corn—each of which is costly. The rancher
and the farmer could bargain with each other to decide who should bear the cost
of the damage. Alternatively, the law could intervene and assign liability for the
damages.

There are two specific rules the law could adopt:

1. The farmer is responsible for keeping the cattle off his property, and he
must pay for the damages when they get in (a regime we could call “ranch-
ers’ rights” or “open range”), or

2. The rancher is responsible for keeping the cattle on her property, and she
must pay for the damage when they get out (“farmers’ rights” or “closed
range”).

Under the first rule, the farmer would have no legal recourse against the dam-
age done by his neighbor’s cattle. To reduce the damage, the farmer would have to
grow less corn or fence his cornfields. Under the second rule, the rancher must build
a fence to keep the cattle on her property. If the cattle escape, the law could ascer-
tain the facts, determine the monetary value of the damage, and make the rancher
pay the farmer.

Which law is better? Perhaps you think that fairness requires injurers to pay for the
damage they cause. If so, you will approach the question as traditional lawyers do, by
thinking about causes and fairness. The rancher’s cows harm the farmer’s crops, but the
farmer’s crops do not harm the rancher’s cows. The cause of the harm runs from
rancher to farmer, and many people believe that fairness requires the party who causes
harm to pay for it.

Professor Coase, however, answered in terms of efficiency. All other things equal,
we would like the legal rule to encourage efficiency in both ranching and farming.

IV. An Economic Theory of Property 83

This approach yielded a counterintuitive conclusion, which can be explained using
some numbers. Suppose that, without any fence, the invasion by the cattle costs the
farmer $100 per year in lost profits from growing corn. The cost of installing and main-
taining a fence around the farmer’s cornfields is $50 per year, and the cost of installing
a fence around the ranch is $75 per year. Thus, we are assuming that damage of $100
can be avoided at an annual cost of $50 by the farmer or $75 by the rancher. Obviously,
efficiency requires the farmer to build a fence around his cornfields, rather than the
rancher to build a fence around her ranch.

Now, consider what will happen under either legal rule. Under the first legal rule
(ranchers’ rights), the farmer will bear damage of $100 each year from the wandering
cattle. He can eliminate this damage at a cost of $50 per year, for a net savings of $50
per year. Therefore, the first rule will cause the farmer to build a fence around his corn-
fields. Under the second rule (farmers’ rights), the rancher can escape liability for $100
at a cost of $75. Consequently, the second rule will cause the rancher to build a fence
around her ranch, thus saving $25. Apparently, the first rule, which saves $50, is more
efficient than the second rule, which saves $25. But this efficiency is only apparent; it
is not real.

We may begin our understanding of this apparent puzzle by first imagining how
the rancher and the farmer could have resolved their problem by cooperative bargain-
ing and then comparing that outcome with the apparent outcomes under the different
legal rules. Suppose that the farmer and the rancher had fallen in love, married, and
combined their business interests. They would then maximize the combined profits
from farming and ranching, and these joint profits will be highest when they build a
fence around the cornfields, not around the ranch. Consequently, the married couple
will build a fence around the cornfields, regardless of whether the law is the first rule
or the second rule. In other words, they will cooperate to maximize their joint profits,
regardless of the rule of law.

We have seen that the first rule is more efficient than the second if the farmer and
the rancher follow the law without cooperating, but that the law makes no difference to
efficiency when they cooperate. The farmer and the rancher do not need to get married
in order to cooperate. Rational businesspeople can often bargain together and agree on
terms of cooperation. By bargaining to an agreement, rather than following the law
noncooperatively, the rancher and the farmer can save $25. That is, if the parties can
bargain successfully with each other, the efficient outcome will be achieved, regardless
of the rule of law.

Recall that the most efficient outcome is for the farmer to build a fence around his
cornfields, and that when the parties simply follow the law without cooperating, the
second rule (farmers’ rights) leads to the apparent inefficiency of the rancher’s build-
ing a fence around her ranch. But consider how bargaining might proceed under the
second rule:

RANCHER: “The law makes me responsible for any damage that my cattle do to your
crops. There would be no damage if there was a fence. I can fence my ranch for
$75 per year, whereas you can fence your cornfields for $50 per year. Let’s make a
deal. I’ll pay you $50 per year to fence your cornfield.”

84 C H A P T E R 4 An Economic Theory of Property

FARMER: “If I agree, and you pay me $50 per year to fence my cornfields, I won’t be
any better off than if I did nothing and you had to fence your ranch. However, you’ll
save $25. You shouldn’t receive all of the gains from cooperation. You should give me
a share of the gains by paying me more than $50 per year for fencing my cornfields.”

RANCHER: “OK. Let’s split the savings from cooperation. I’ll pay you $62.50 per
year, and you build the fence. That way we’ll each receive half of the $25 gained by
cooperating.”

FARMER: “Agreed.”

Note the important implication: Cooperation leads to the fence’s being built around
the farmer’s cornfields, despite the fact that the second legal rule (farmers’ rights) was con-
trolling. The greater efficiency of the first legal rule is apparent, not real. Note, also, the
parallel between bargaining over the right of ownership of a used car from earlier in the
chapter and the rights of ownership of land. Adam owns the car, and Blair values it more
than Adam. By bargaining to an agreement, they can create a surplus and divide it between
them. Similarly, the second legal rule imposes an obligation on the rancher to constrain her
cattle, but the farmer can constrain them at less cost than the rancher. By bargaining to an
agreement, both parties can save costs and divide the savings between them.9

Let’s generalize what we have learned from this exercise. When one activity inter-
feres with another, the law must decide whether one party has the right to interfere or
whether the other party has the right to be free from interference. Fairness apparently re-
quires the party who causes harm to pay for it. In contrast, efficiency requires allocating
the right to the party who values it the most. When the parties follow the law noncooper-
atively, the legal allocation of rights matters to efficiency. When the parties bargain suc-
cessfully, the legal allocation of rights does not matter to efficiency. Given successful
bargaining, the use of resources (the placement of a fence, the number of cattle run, the
extent of land planted in cornfields, and so forth) is efficient, regardless of the legal rule.

We have discussed “successful bargaining,” but we have not discussed why bar-
gains sometimes succeed and sometimes fail. Bargaining occurs through communica-
tion between the parties. Communication has various costs, such as renting a conference
room, hiring a stenographer, and spending time in discussion. Coase used the term
“transaction costs” to refer to the costs of communicating, as well as to a variety of

9 The bargaining situation is quite different if the law adopts the first rule (ranchers’ rights), rather than the
second rule (farmers’ rights). Under the first rule, the farmer is responsible for building a fence to keep the
cattle out of his cornfields. In these circumstances, cooperation between the farmer and the rancher does
not save costs relative to following the law noncooperatively. Consequently, under the first rule, the farmer
will go ahead and build the fence, without any bargaining. The first rule has an analogy in the used-car ex-
ample. Recall that Blair values the car more than Adam does, which is why a surplus can be created by
Adam’s selling the car to Blair. If Blair initially owns the car, there is nothing to be gained by bargaining
with Adam or cooperating with him. Thus, Blair’s owning the car is analogous to ranchers’ rights. In the
car example, there is no scope for a bargain because the party who values the car the most already owns it;
in the cattle-corn example, there is no scope for a bargain because the party who can fence the cattle at least
cost already has the duty to build the fence.

IV. An Economic Theory of Property 85

high

bargaining fails;
legal rights matter
to efficiency

bargaining succeeds;
legal rights do not
matter to efficiency

Transaction Costs

threshold

low

FIGURE 4.2
A threshold level of transaction costs
that distinguishes the areas in which
the Coase Theorem applies and does
not apply.

other costs that we will discuss later. In fact, he used “transaction costs” to encompass
all of the impediments to bargaining. Given this definition, bargaining necessarily suc-
ceeds when transaction costs are zero. We can summarize this result by stating this ver-
sion of the Coase Theorem:

When transaction costs are zero, an efficient use of resources results from private bar-
gaining, regardless of the legal assignment of property rights.

Now we must relate the Coase Theorem to our larger project of developing an eco-
nomic theory of property. The theorem states abstractly what our example showed con-
cretely: If transaction costs are zero, then we do not need to worry about specifying
legal rules regarding property in order to achieve efficiency. Private bargaining will
take care of such issues as which things may be owned, what owners may and may not
do with their property, and so on.

By specifying the circumstances under which property law is unimportant to effi-
cient resource use, the Coase Theorem specifies implicitly when property law is impor-
tant. The assignment of property rights might be crucial to the efficient use of resources
when transaction costs are not zero.

To make the point more explicit, we posit this corollary to the Coase Theorem:

When transaction costs are high enough to prevent bargaining, the efficient use of
resources will depend on how property rights are assigned.

Figure 4.2 represents the corollary graphically. Transaction costs lie on a spectrum
from zero to infinity. In any particular situation, a threshold level of transaction costs di-
vides the spectrum into a region in which bargaining succeeds and one in which it fails.

To appreciate the corollary, let us return to the rancher and the farmer. Bargaining
to an agreement requires communication. Assume that communication is costly.
Specifically, assume that the transaction costs of bargaining are $35. Transaction costs
must be subtracted from the surplus in order to compute the net value of cooperating.
Suppose that the second legal rule (farmers’ rights) prevails, so that a surplus of $25 can
be achieved by an agreement that the rancher will pay the farmer to fence the cornfields.
The net value of the bargain is the cooperative surplus minus the transaction costs—
$25 – $35 = -$10. Recognizing that the net value of the bargain is negative, the parties
will not bargain. If the parties do not bargain, they will follow the law noncooperatively.
Specifically, the farmer will assert his right to be free from invasions of cattle, and the
rancher will fence the ranch, which is inefficient. In order to avoid this inefficiency, the
law would have to adopt the first rule (ranchers’ rights), in which case the parties will
not bargain, and they will achieve efficiency by following the law noncooperatively.

86 C H A P T E R 4 An Economic Theory of Property

Sometimes the threshold’s location is obvious to everyone. For example, when a mi-
nor road crosses a main road, the law should prescribe that drivers in the minor road must
yield to drivers on the main road. Motorists do not have time to bargain with each other
and arrive at this result on their own. Sometimes the threshold’s location is not obvious
and people sharply disagree over policy. Motorists cannot buy insurance against their own
pain and suffering from an accident. Legal scholars disagree sharply over whether such
insurance is unavailable because transaction costs are prohibitively high or because mo-
torists do not value compensation for pain and suffering enough to pay for it.

QUESTION 4.3: Suppose that a railroad runs beside a field in which com-
mercial crops are grown. The railroad is powered by a steam locomotive that
spews hot cinders out of its smokestack. From time to time those cinders land
on the crops nearest to the track and burn them to the ground. Assume that
each year, the farmer whose crops are burned loses $3000 in profits, and that
the annual cost to the railroad of installing and maintaining a spark-arrester
that would prevent any damage to the crops is $1750. Does it matter to the ef-
ficient use of the farmer’s land or to the efficient operation of the railroad
whether the law protects the farmer from invasion by sparks or allows the rail-
road to emit sparks without liability? Why or why not?

The Coase Theorem is so remarkable that many people have questioned it.
Although we cannot discuss this rich literature here, we have embodied some of the
most important points in the following questions:

QUESTION 4.4: The long run. Some commentators thought that the Coase
Theorem might be true in the short run but not in the long run. In the example of
the farmer and the rancher, changing the use of fields takes time. For example, to
convert a field from grazing land to farmland, the farmer must fence and plough
the land. The efficiency of the Coase Theorem in the long run depends on the
ability of private bargaining to accommodate any additional costs of altering re-
source use over long time periods as relative prices and opportunity costs change.
Discuss some ways that a contract for long-run cooperation between the rancher
and the farmer would differ from a contract for short-run cooperation.

QUESTION 4.5: Invariance. With zero transaction costs, the farmer fences the
cornfield rather than the rancher fencing the ranch—regardless of the rule of law.
Notice that in this example, the use of the fields for cattle-ranching and corn-
growing is the same, regardless of the initial assignment of property rights. This
version of the Coase Theorem is called the invariance version (because the use
of resources is invariant to the assignment of property rights). This version turns
out to be a special case. The more general case is one in which the resource allo-
cation will be efficient (but not necessarily identical), regardless of the assign-
ment of property rights. There will be a Pareto-efficient allocation of goods and
services, but it may be different from the Pareto-efficient allocation that would
have resulted from assigning that same entitlement to someone else.

To illustrate, assume that farmers like to eat more corn and less beef,
whereas ranchers like to eat more beef and less corn. Assume that farmers and

IV. An Economic Theory of Property 87

ranchers own their own land, that transaction costs are zero, and that fence is
costly relative to their incomes. The change from “ranchers’ rights” to “farm-
ers’ rights” will increase the income of farmers and decrease the income of
ranchers. Consequently, the demand for corn will increase, and the demand for
beef will decrease. Greater demand for corn requires the planting and fencing
of more cornfields. Thus, the change in law causes the building of more fences.
Remember the distinction between “price effects” and “income effects” in
demand theory? Can you use these concepts to explain this example?10

QUESTION 4.6: Endowment effects. Surveys and experiments reveal that
people sometimes demand much more to give up something that they have
than they would be willing to pay to acquire it. To illustrate, contrast a situa-
tion in which people have an opportunity to “sell” the clean air that they cur-
rently enjoy to a polluter to the situation in which people currently not
enjoying clean air have an opportunity to “buy” clean air from a polluter.
Evidence suggests that people may demand a higher price to “sell” a right to
clean air than they would pay to “buy” the same right. An endowment is an
initial assignment of ownership rights. The divergence between buying and
selling price is called an endowment effect because the price varies depending
on the initial assignment of ownership.

Why might farmers place a different value on the right to be free from
straying cattle depending on whether they were selling or buying that right? Is
it rational to place different values on those rights? How do these flip-flops in
the relative valuation complicate an efficiency analysis of the assignment of
property rights?

QUESTION 4.7: Social norms. Social norms often evolve to cope with ex-
ternal costs, without bargaining or law. For example, a social norm in a county
in northern California requires that ranchers assume responsibility for control-
ling their cattle, even though parts of the county are “open range” (that is,
areas in which legal responsibility rests with farmers). Furthermore, the ranchers
and farmers in this county apparently do not engage in the kind of bargaining
envisioned by the Coase Theorem. How damaging are these facts to Coase’s
analysis? Why would you expect neighbors in long-run relationships to adopt
efficient norms to control externalities?11

10 In the long run, ranchland will be more valuable if the rancher does not have to install fences, and farm-
land will be more valuable if the farmer does not have to install fences. If ranchers and farmers rent their
land, the rule that determines the cost of fencing may affect the rental value of the land, not the profitabil-
ity of the activity that occurs on it. On the various versions of the Coase Theorem, see ROBERT D. COOTER,
The Coase Theorem, in THE NEW PALGRAVE: A DICTIONARY OF ECONOMICS (1987). On the special assump-
tions underlying the invariance version of the Coase Theorem, see the graphical treatment in THOMAS S.
ULEN, Flogging a Dead Pig: Professor Posin on the Coase Theorem, 38 WAYNE L. REV. 91 (1991).

11 See Robert Ellickson, Of Coase and Cattle: Dispute Resolution Among Neighbors in Shasta County, 38
STAN. L. REV. 623 (1986).

88 C H A P T E R 4 An Economic Theory of Property

Web Note 4.1

There is more on the Coase Theorem at our website, where we pose additional
questions and describe some experimental studies designed to test the Coase
Theorem.

B. The Elements of Transaction Costs
What are transaction costs? Are they ever really negligible? We cannot use the

Coase Theorem to understand law without answering these questions. Transaction
costs are the costs of exchange. An exchange has three steps. First, an exchange partner
has to be located. This involves finding someone who wants to buy what you are sell-
ing or sell what you are buying. Second, a bargain must be struck between the ex-
change partners. A bargain is reached by successful negotiation, which may include the
drafting of an agreement. Third, after a bargain has been reached, it must be enforced.
Enforcement involves monitoring performance of the parties and punishing violations
of the agreement. We may call the three forms of transaction costs corresponding to
these three steps of an exchange: (1) search costs, (2) bargaining costs, and (3) enforce-
ment costs.

QUESTION 4.8: Classify each of the following examples as a cost of search-
ing, bargaining, or enforcing an agreement to purchase a 1957 Chevrolet:

a. Haggling over the price.
b. Collecting the monthly payments for the purchase of the car.
c. Taking time off from work for the buyer and seller to meet.
d. Purchasing an advertisement in the “classified” section of the newspaper.
e. Purchasing a newspaper to obtain the “classified” section.
f. The buyer asking the seller questions about the car’s ignition system.

When are transaction costs high, and when are they low? Consider this question
by looking at the three elements of the costs of exchange. Search costs tend to be high
for unique goods or services, and low for standardized goods or services. To illustrate,
finding someone who is selling a 1957 Chevrolet is harder than finding someone who
is selling a soft drink.

Turning from search costs to bargaining costs, note that our examples of bargaining
assumed that both parties know each other’s threat values and the cooperative solution.
Game theorists say that information is “public” in negotiations when each party knows
these values. (Game theorists refer to these negotiations as “common knowledge” situa-
tions.) Conversely, information is “private” when one party knows some of these values
and the other does not. If the parties know the threat values and the cooperative solution,
they can compute reasonable terms for cooperation. In general, public information facil-
itates agreement by enabling the parties to compute reasonable terms for cooperation.
Consequently, negotiations tend to be simple and easy when information about the threat
values and the cooperative solution is public. To illustrate, negotiations for the sale of a
watermelon are simple because there is not much to know about it.

IV. An Economic Theory of Property 89

Negotiations tend to be complicated and difficult when information about threat
values and the cooperative solution is private. Private information impedes bargain-
ing because much of it must be converted into public information before computing
reasonable terms for cooperation. In general, bargaining is costly when it requires
converting a lot of private information into public information. To illustrate, negotia-
tions for the sale of a house involve many issues of finance, timing, quality, and price.
The seller of a house knows a lot more about its hidden defects than the buyer knows,
and the buyer knows a lot more about his or her ability to obtain financing than the
seller knows. Each attempts to extract these facts from the other over the course of
negotiations. To a degree, the parties may want to divulge some information. But they
may be reluctant to divulge all. Each party’s share of the cooperative surplus de-
pends, in part, on keeping some information private. But concluding the bargain re-
quires making some information public. Balancing these conflicting pulls is difficult
and potentially costly.

There is an extensive literature on bargaining games, including a large number of
carefully constructed experiments testing the Coase Theorem.12 One of the most robust
conclusions of these experiments is that bargainers are more likely to cooperate when
their rights are clear and less likely to agree when their rights are ambiguous. Put in
more formal terms, bargaining games are easier to solve when the threat values are
public knowledge. The rights of the parties define their threat values in legal disputes.
One implication of this finding is that property law ought to favor criteria for determin-
ing ownership that are clear and simple. The most immediate prescription for efficient
property law is to make rights clear and simple. For example, a system for the public
registration of ownership claims to land avoids many disputes and makes settlement
easier for those that arise. Similarly, the fact that someone possesses or uses an item of
property is easy to confirm. In view of this fact, the law gives weight to possession and
use when determining ownership. Conversely, unclear ownership rights are a major ob-
stacle to cooperation and a major cause of wasted resources. Thus, squatters who oc-
cupy land owned by others in developing countries fail to improve their dwellings
because it is not clear that they would own the improvements.

Most of our bargaining examples concern two parties. Communication between
two parties is usually cheap, especially when they are near each other. However, many
bargains involve three or more parties. Bargaining becomes more costly and difficult as
it involves more parties, especially if they are dispersed from one another. This fact
may explain why treaties involving many nations are so difficult to conclude.

Finally, the parties may want to draft an agreement, and this may be costly because
it must anticipate many contingencies that can arise to change the value of the bargain.

12 See J. KEITH MURNIGHAN, BARGAINING GAMES (1992) for a highly readable summary of this literature. For
specific experiments on the Coase Theorem, see Elizabeth Hoffman & Matthew Spitzer, The Coase
Theorem: Some Experimental Tests, 25 J. LAW & ECON. 73 (1982), and Hoffman & Spitzer, Experimental
Tests of the Coase Theorem with Large Bargaining Groups, 15 J. LEGAL STUD. 149 (1986). Ian Ayres has
recently argued that, contrary to these findings, ambiguous rights induce bargaining. See our website
for more.

90 C H A P T E R 4 An Economic Theory of Property

Another obstacle to bargaining is hostility. The parties to the dispute may have
emotional concerns that interfere with rational agreement, as when a divorce is bitterly
contested. People who hate each other often disagree about the division of the coopera-
tive surplus, even though all the relevant facts are public knowledge. To illustrate, many
jurisdictions have rules for dividing property on divorce that are simple and predictable
for most childless marriages. However, a significant proportion of these divorces are
litigated in court rather than settled by negotiation. In these circumstances, lawyers can
facilitate negotiations by interposing themselves between hostile parties.

Even without hostility, however, bargaining can be costly because negotiators may
behave unreasonably—for example, by pressing their own advantage too hard (what
lawyers refer to as “overreaching”). An essential aspect of bargaining is forming a
strategy. In forming a bargaining strategy, each party tries to anticipate how much the
opponent will concede. If the parties miscalculate the other party’s resolve, each will
be surprised to find that the other does not concede, and as a result, negotiations may
fail. Miscalculations are likely when the parties do not know each other, when cultural
differences obscure communication, or when the parties are committed to conflicting
moral positions about fairness.

Enforcement costs, the third and final element of transaction costs, arise when an
agreement takes time to fulfill. An agreement that takes no time to fulfill has no en-
forcement costs. An example is simultaneous exchange, in which I give you a dollar
and you give me a watermelon. For complex transactions, monitoring behavior and
punishing violations of the agreement can be costly. To illustrate, consider the example
from the beginning of this chapter of Bloggs’s desire to drain a wetlands on his prop-
erty in order to develop it as a residential area. Suppose that the city permits him to
build on a small part of the wetlands, provided that he does not harm the rest. Officials
must watch him to be sure that he keeps his promise. Furthermore, officials may require
Bloggs to post bond, which will be confiscated if he harms the rest of the wetlands and
returned to him if he completes construction without doing harm. In general, enforce-
ment costs are low when violations of the agreement are easy to observe and punish-
ment is cheap to administer.

Let us summarize what we have learned about transaction costs. Transactions have
three stages, each of which has a special type of cost—search costs, bargaining costs,
and enforcement costs. These costs vary along a spectrum from zero to indefinitely
large, depending on the transaction. Characteristics of transactions that affect their
costs are summarized in Table 4.3.

QUESTION 4.9: Rank the following six transactions from lowest to highest
transaction costs. Explain your ranking by reference to the costs of search,
bargaining, and enforcement. (There is no uniquely correct answer.)

a. Getting married.
b. Buying an artichoke.
c. Acquiring an easement to run a gas line across your neighbor’s property.
d. Selling a Burger King franchise.
e. Going to college.
f. Purchasing a warranty for a new car.

IV. An Economic Theory of Property 91

TABLE 4.3
Factors Affecting Transaction Costs

Lower Transaction Costs Higher Transaction Costs

1. Standardized good or service
2. Clear, simple rights
3. Few parties
4. Friendly parties
5. Familiar parties
6. Reasonable behavior
7. Instantaneous exchange
8. No contingencies
9. Low costs of monitoring

10. Cheap punishments

1. Unique good or service
2. Uncertain, complex rights
3. Many parties
4. Hostile parties
5. Unfamiliar parties
6. Unreasonable behavior
7. Delayed exchange
8. Numerous contingencies
9. High costs of monitoring

10. Costly punishments

QUESTION 4.10: Consider the right to smoke or to be free from smoke in
the following situations. In which situations do you think that transaction costs
are so high that they preclude private bargains, and in which cases do you
think that transaction costs are low enough for private bargains to occur?
Explain your answer.

a. Smoking in a private residence.
b. Smoking in a public area, such as a shopping mall, an indoor arena or

concert hall, or an outdoor stadium.
c. Smoking in hotel rooms.
d. Smoking on commercial airline flights.

What sorts of arguments might be made for and against a bargaining or
more interventionist means of dealing with each issue? To what extent are so-
cial norms, not law, determinative of the outcome?

C. The Normative Coase and Hobbes Theorems
We have been speaking thus far as if the Coase Theorem’s only lesson for property

law is that the law should determine the level of transaction costs and react accordingly.
But we can go further.

Thus far, we have spoken of transaction costs as if they are exogenous to the legal
system—that is, as if they are determined solely by objective characteristics of bargain-
ing situations outside the domain of the law. This is not always the case. Some transac-
tion costs are endogenous to the legal system in the sense that legal rules can lower
obstacles to private bargaining. The Coase Theorem suggests that the law can encour-
age bargaining by lowering transaction costs.

To illustrate numerically, if the surplus from exchange is $25 and transaction costs
are $30, then the parties can obtain a net benefit of $25 – $30 = -$5 from a private

92 C H A P T E R 4 An Economic Theory of Property

agreement. In other words, at least one of the parties will lose from private exchange.
A rational person will not voluntarily trade at a loss. So, private exchange will not oc-
cur among rational people when the net benefit is negative. If, however, law lowers
transaction costs to $10, then the net benefit of exchange is $25 – $10 = $15. When the
surplus exceeds transaction costs, the net benefit from private exchange is positive, so
both parties can gain from private exchange. Private exchange will ordinarily occur
among rational people when the net benefit is positive.

Lowering transaction costs “lubricates” bargaining. An important legal objective is
to lubricate private bargains by lowering transaction costs. One important way for the
law to do this is by defining simple and clear property rights. It is easier to bargain
when legal rights are simple and clear than when they are complicated and uncertain.
To illustrate, the rule “first in time, first in right” is a simple and clear way to determine
ownership claims. Similarly, requiring public recording of property claims makes de-
termining ownership easier. Further, making those records searchable on the Internet
may lower transaction costs even more. You will encounter many examples throughout
this book of other ways that law lubricates bargaining. By lubricating bargaining, the
law enables the private parties to exchange legal rights, thus relieving lawmakers of the
difficult task of allocating legal rights efficiently.13

We can formalize this principle as the Normative Coase Theorem:

Structure the law so as to remove the impediments to private agreements.

The principle is normative because it offers prescriptive guidance to lawmakers. The
principle is inspired by the Coase Theorem because it assumes that private exchange,
in the appropriate circumstances, can allocate legal rights efficiently. To illustrate the
principle’s application, the dramatic worldwide trend toward privatization in the 1990s
removed many regulatory impediments to private agreements.

Besides encouraging bargaining, a legal system tries to minimize disagreements
and failures to cooperate, which are costly to society. The importance of minimizing
the losses from disagreements was especially appreciated by the seventeenth-century
English philosopher Thomas Hobbes. Hobbes thought that people would seldom be ra-
tional enough to agree on a division of the cooperative surplus, even when there were
no serious impediments to bargaining.14 Their natural cupidity would lead them to
quarrel unless a third, stronger party forced them to agree. These considerations sug-
gest the following principle of property law, which we may call the Normative Hobbes
Theorem:

Structure the law so as to minimize the harm caused by failures in private agreements.15

13 As we shall see in Chapter 8, contract law may be seen as an application of the Normative Coase Theorem
in that much of that area of the law may be seen as an attempt to lower the transaction costs of concluding
consensual agreements.

14 Because Hobbes wrote in the seventeenth century, he did not express himself in quite these terms, but this
kind of argument is pervasive in his classic work, LEVIATHAN (1651). The modern idea underlying the pes-
simism of Hobbes concerning distribution is the fact that game theory has no generally accepted way to
choose among core allocations.

15 This idea is developed at length in Cooter, The Cost of Coase, 11 J. LEGAL STUD. 1 (1982).

IV. An Economic Theory of Property 93

According to this principle, the law should be designed to prevent coercive threats and
to eliminate the destructiveness of disagreement.

When the parties fail to reach a private agreement where one is, in fact, possible,
they lose the surplus from exchange. To minimize the resulting harm, the law should
allocate property rights to the party who values them the most. By allocating property
rights to the party who values them the most, the law makes exchange of rights unnec-
essary and thus saves the cost of a transaction. To illustrate, the Normative Hobbes
Theorem requires the law to create “open range” (ranchers’ rights), rather than “closed
range” (farmers’ rights) in situations corresponding to our previous example.

These two normative principles of property law—minimize the harm caused by
private disagreements over resource allocation (the Normative Hobbes Theorem), and
minimize the obstacles to private agreements over resource allocation (the Normative
Coase Theorem)—have wide application in law. In combination with the Coase
Theorem discussed earlier and its corollary, these principles will form the heart of our
economic analysis of property law in the remainder of this and the following chapter.

D. Lubricate or Allocate? Coase versus Hobbes
The Coase and Hobbes Theorems characterize two ways that law can increase effi-

ciency when transaction costs are positive. First, law can lubricate private exchange by
lowering transaction costs. Second, law can allocate rights to the party who values
them the most.

Now we consider how a lawmaker might choose between lubricating and allocat-
ing. Return to our example of the farmer and the rancher, where fencing costs the
rancher $75 and the farmer $50. Assume that law assigns the obligation to fence to the
rancher (farmers’ rights). Given these facts, a surplus of $25 could be achieved by
transferring the obligation to fence from the rancher to the farmer (ranchers’ rights).
Assume, however, that transaction costs of private exchange equal $35, so the transfer
is blocked. What is to be done? If law can lower the transaction costs of exchange from
$35 to $10, transaction costs will no longer block private exchange. When private ex-
change is not blocked, the obligation of the rancher to build the fence can be transferred
to the farmer, thus creating a net benefit of $15.

Alternatively, assume that the law cannot lower the transaction costs of exchange.
The other possible remedy is to change the law and assign the obligation to fence to the
farmer (ranchers’ rights), not the rancher (farmers’ rights). If the farmer has the obliga-
tion to fence, the legal rights are allocated efficiently. When the right is already allo-
cated efficiently, exchange of the right would produce a negative surplus. Exchange is
unnecessary and will not occur.

Unfortunately, however, lawmakers often do not know who values rights the most,
and finding out can be difficult. To illustrate, consider the problem of finding out the
cost of fencing the farmer’s crops. When testifying in court, the farmer has an incentive
to exaggerate these costs. Knowing this fact, the judge and the jury are not sure whether
to believe the farmer.

Lawmakers with limited information face a trade-off between transaction costs
and information costs. On one hand, by strictly following precedent, courts avoid the

94 C H A P T E R 4 An Economic Theory of Property

information costs of determining who values a right the most. With strict adherence to
precedent by courts, the parties must bear the transaction costs of correcting inefficient
legal allocations of rights. On the other hand, the courts can attempt to determine who
values a legal right the most and adjust the law accordingly. With legal reallocation of
rights, the courts or other lawmakers must bear the information costs of determining
who values a right the most. Efficiency requires the courts to do whichever is cheaper.

To formalize this claim, let IC denote the information costs to a court of determin-
ing who values a legal right the most. Let TC indicate the transaction costs of trading
legal rights. Efficient courts would follow this rule:

To illustrate the application of this principle, as population increases and land use in-
tensifies, areas in the western United States convert from open to closed range. Assume
that a judge or panel of legal experts must consider whether to leave some range in the
country open or to close it. In approaching the question, the judge or commission should
balance the transaction costs of private bargains between ranchers and farmers, and the
cost to lawmakers of trying to determine the fencing costs of ranchers and farmers.

QUESTION 4.11:

a. When transaction costs are low enough, efficient resource allocation will
follow regardless of the particular assignment of property rights. When
transaction costs are high enough, efficient resource allocation requires
assigning property rights to the party who values them the most. Give an
example of each case.

b. Can you use the Normative Hobbes Theorem to justify legislation regulating
the collective bargaining process between employers and employee unions?

c. When people strongly disagree, they may try to harm each other, or they
may walk away from a potentially profitable exchange. What does the
Normative Hobbes Theorem suggest the response of the law should be to
these two possibilities?

V. How Are Property Rights Protected?
Now we have the tools to answer another of the four fundamental questions of

property law that we posed at the beginning of this chapter: “What are the remedies for
the violation of property rights?” This question concerns how a court should respond
when a private person or the government interferes with someone’s property rights. Our
discussion in this chapter will focus on interference by a private person. We consider
government interference in the next chapter.

A. Damages and Injunctions
First, we need some background. The remedies available to a common law court are

either legal or equitable. The principal legal remedy is the payment of compensatory

TC 6 IC Q strictly follow precedent.
IC 6 TC Q allocate the legal right initially to the person who values it the most;

V. How Are Property Rights Protected? 95

16 There are two more things you should be aware of. First, if a defendant fails to pay a judgment that a court
has awarded against him or her, the defendant’s property may be seized and sold in order to raise the judg-
ment amount. Second, compensatory damages are to be distinguished from punitive damages, which are
money damages over and above compensatory damages assessed against the defendant. The purpose of
punitive damages is to punish the defendant, not to compensate the plaintiff. We discuss punitive damages
in Chapter 7.

17 The consequences to a defendant of violating an equitable decree are far more serious than the conse-
quences of failing to pay a monetary judgment. A defendant’s failure to abide by an injunction not only
leaves the plaintiff at a loss, but it also constitutes an insult to the authority of the court. A defendant who
ignores an equitable order may be held in contempt of court and imprisoned until she agrees to abide by
the order.

money damages by the defendant to the plaintiff. These damages are a sum of money
that compensates the plaintiff for the wrongs inflicted on her by the defendant. The
court determines the appropriate amount of money that will, as the saying goes, “make
the plaintiff whole.” The measurement of this sum is a complex subject itself, which
we discuss later.16 Equitable relief consists of an order by the court directing the defen-
dant to perform an act or to refrain from acting in a particular manner. This order is fre-
quently in the form of an injunction, which is said to “enjoin” the defendant to do or to
refrain from doing a specific act.17

Notice that legal relief is “backward-looking” in the sense that it compensates a
plaintiff for a harm already suffered, whereas equitable relief is “forward-looking” in
the sense that it prevents a defendant from inflicting a harm on the plaintiff in the fu-
ture. Thus, a court may combine the two forms of relief, awarding money damages for
past harms and enjoining acts that could cause future harm.

Damages are the usual remedy for broken promises and accidents, whereas injunc-
tion is the usual remedy for appropriating, trespassing, or interfering with another’s
property. In other words, damages are the usual remedy in the law of contracts and
torts, whereas injunction is the usual remedy in the law of property. For these reasons,
damages are often referred to in the legal literature as a “liability rule,” while equitable
relief is typically called a “property rule.” To illustrate, the farmer will have to pay
damages to the rancher for breach of a contract to deliver hay or for accidentally shoot-
ing the rancher’s cow while hunting. But if the cattle trespass on the farmer’s crops (and
if farmers have a right to be free from the depredations of stray cattle), then the court
will probably award damages for past harm and enjoin the rancher to constrain her cat-
tle in the future.

B. Laundry and Electric Company: An Example
An injunction may appear to be an absolute proscription on an act. For example, if

the court were to enjoin the future invasion of the farmer’s cornfields by the rancher’s
cattle, one might interpret that as meaning that the rancher will have to erect a fence.
This is a mistake. The injunctive remedy does not prevent the invasion of the farmer’s
property by the rancher’s cattle from ever occurring, only from its occurring without the
consent of the farmer. The farmer is free to make a contract promising not to enforce the

96 C H A P T E R 4 An Economic Theory of Property

injunction. To illustrate, the farmer might agree not to enforce the injunction in
exchange for payment of a sum of money by the rancher.18

Given these facts, the right to an injunction should be regarded as a clear assign-
ment of a property right. Once the property right is clearly assigned, its owner may
strike a bargain to sell it. Thus, if the court enjoined the rancher from allowing future
invasion by her cattle, this could be viewed as a declaration that the farmer has the
legally enforceable right to be free from invasion by cattle. If the rancher’s value on be-
ing allowed to invade the farmer’s property is greater than the farmer’s value on being
free from invasion, there is scope for a bargain in which the rancher buys the right from
the farmer.

Most legal disputes are settled by bargaining between the parties without going to
trial, but the terms of the bargain are affected by the remedy that would be available at
trial.19 Specifically, the terms of the bargain are different depending on whether the
remedy is damages or injunction. An example from Chapter 1 will help you to under-
stand the relationship between remedies and bargains.

FACTS: The E Electric Company emits smoke, which dirties the wash at the L
Laundry. No one else is affected because E and L are near each other and far from
anyone else. E can abate this external cost by installing scrubbers on its stacks, and L
can reduce the damage by installing filters on its ventilation system. The installation
of scrubbers by E or filters by L completely eliminates the damage from pollution.
Table 4.4 shows the profits of each company, depending on what action is taken to re-
duce the pollution. (The profits that are shown in the matrix exclude any compensa-
tion that might be paid or received as a consequence of a legal dispute.)

The numbers in Table 4.4 can be explained as follows. When E does not install
scrubbers, its profits are $1000 (regardless of what the laundry does). When L does not
install filters and does not suffer pollution damages (because E has installed scrubbers),
L’s profits are $300. Pollution destroys $200 of L’s profits. L can avoid this by in-
stalling filters at a cost of $100, or E can avoid it by installing scrubbers at a cost of
$500. Check to see that you can use these facts to explain the numbers in the table.

The most efficient outcome is, by definition, a situation in which the total profits
for the two parties, called the “joint profits,” are greatest. The joint profits are found by
adding the two numbers in each cell of the table. Joint profits are maximized in the
northeast cell, where $1200 is attained when E does not install scrubbers and L installs
filters.

The harm caused by pollution represents a source of contention between E and L.
They may be able to settle their disagreement and cooperate with each other, or they
may fail to cooperate and litigate their dispute. What we are interested in determining
here is how the remedy available from a court may induce the parties to achieve the
efficient solution and thus to minimize the harm of pollution.

18 This inducement to bargain may be more theoretical than real. For a discussion of research by Ward
Farnsworth about post-injunction bargains, see the material at Web Note 4.2 on our website.

19 This is referred to as “bargaining in the shadow of the law.”

V. How Are Property Rights Protected? 97

TABLE 4.4
Profits Before Legal Action‡

LAUNDRY

No Filter Filter

ELECTRIC
COMPANY

No Scrubbers 1000
100

1000 200

Scrubbers 500
300

500
200

‡The electric company’s profits are given first in the lower-left corner of each cell; the laun-
dry’s profits are given in the upper-right corner of each cell.

TABLE 4.5
Profits from Bargaining Under Three Legal Rules

Noncooperation Surplus Cooperation

E L E L

Rule 1 Polluter’s Right 1000 200 0 1000 200
Rule 2 Damages 800 300 100 850 350
Rule 3 Injunction 500 300 400 700 500

Suppose that E and L litigate their disagreement. Three alternative rules of law
could be applied in the event of a trial:

1. Polluter’s Right: E is free to pollute.
2. Pollutee’s Right to Damages: L is entitled to compensatory damages from

E. (Compensatory damages are a sum of money that E pays to L to make
up for L’s reduced profits due to E’s pollution.)

3. Pollutee’s Right to Injunction: L is entitled to an injunction forbidding E to
pollute. (An injunction is a court order requiring E to stop polluting.)

Let us determine the value of the noncooperative solution under each of these rules as
depicted in Table 4.5.

Beginning with rule 1, if E is free to pollute, the most profitable action for E is not
to install scrubbers and to enjoy profits of $1000. The most profitable response for L is
to install filters and enjoy profits of $200. Thus, the noncooperative value of the rule of
free pollution is $1200. This is the efficient solution, which is in the northeast cell of
the table.

98 C H A P T E R 4 An Economic Theory of Property

Turning to rule 2, assume that E must pay damages to L and also assume that L has
no legal duty to install filters (no duty to “mitigate”). If E must pay damages to L for
polluting, then L will not bother to install filters. E will have to pay damages to L equal
to the difference between the profits L enjoys when there is no pollution, $300, and the
profits L enjoys with pollution, $100. E has a choice between installing the scrubbers
and paying damages of $200 to L. The more profitable alternative is for E not to install
the scrubbers: It initially realizes $1000 in profits, from which $200 must be subtracted
to pay damages, leaving E with net profits of $800. L enjoys net profits of $300 ($100
from its operations plus $200 from E). The noncooperative value under rule 2 (a rule of
liability for compensatory damages) is then $1100 = $300 + $800. This is the value
in the northwest cell in the table.

Turning to rule 3, if E is enjoined from polluting and responds by installing scrub-
bers, E’s profits equal $500. When E installs scrubbers, L will not bother to install fil-
ters, so L’s profits will be $300. Thus, the noncooperative value under the rule of
enjoining pollution is $800 = $500 + $300, which corresponds to the southwest cell
of the table.

Under the pessimistic assumption that E and L cannot cooperate, only one of the
legal rules produces an efficient outcome—namely, rule 1. Instead of making the pes-
simistic assumption that the parties will be unable to cooperate, suppose we make the
optimistic assumption that the parties can settle their disagreement cooperatively. (We
are assuming that transaction costs are very low.) When E and L cooperate, their best
strategy is to maximize the joint profits of the two enterprises. The profits are maxi-
mized when they take the efficient course of action, which, in this case, is for L to in-
stall filters and E not to install scrubbers, yielding joint profits of $1200. This is the
efficient solution in the northeast cell.

There are, thus, two ways to achieve the efficient solution. One way is for the law
to adopt the rule for which the noncooperative solution is efficient. This solution is
commended by the Normative Hobbes Theorem. In our example (but not necessarily
other pollution examples), the noncooperative solution is efficient under rule 1, which
gives E the freedom to pollute. The other way to achieve efficiency is for the parties to
cooperate. The cooperative solution is efficient under all three of the possible laws.
According to the Coase Theorem, inefficient allocations of legal rights by laws such
as rules 2 and 3 will be cured by private agreements, provided that bargaining is
successful.

If transaction costs equal zero and successful bargaining can cure inefficient laws,
what difference does the law make? One answer is that the law affects the distribution
of the cooperative product, which affects bargaining. To illustrate this point about dis-
tribution, recall how the structure of the law—such as rules 1, 2, and 3—affects the
threat values of the parties. A reasonable bargaining solution is for each party to re-
ceive his or her threat value plus an equal share of the cooperative surplus. Each party
to a bargain would prefer the rule of law that provides him or her with the largest
threat value. Specifically, the threat value of the plaintiff in a property dispute is at
least as great when the remedy for future harm is injunctive relief as when the remedy
is damages. The plaintiff, consequently, prefers the remedy of injunctive relief for fu-
ture harm, or, better yet, injunctive relief for future harm and damages for past harm.

V. How Are Property Rights Protected? 99

In contrast, the defendant prefers the damage remedy for future harm or, better yet, no
remedy.

The effect of the rule of law on the distribution of the cooperative product can be
computed precisely for E and L. Imagine that E and L enter into negotiations, and, to
keep the arithmetic simple, assume that negotiating a settlement or going to trial is
costless for the parties (swallow hard!). The noncooperative payoffs—that is, the prof-
its the parties can get on their own if negotiations fail—are shown in Table 4.5 under
each of the three rules. The cooperative surplus, which equals the difference between
the joint profits from cooperation and the threat values, is shown in the middle column.
A reasonable bargaining solution is for each party to receive his or her threat value plus
half the surplus from cooperation. The payoffs to the two parties from cooperation are
given in the two columns on the right side of the table. Notice that in each case the co-
operative payoffs sum $1200, but that L receives the largest share under the injunctive
rule (rule 3), an intermediate share under damages (rule 2), and the smallest share when
E is free to pollute (rule 1).

QUESTION 4.12: In the preceding example, implementing an injunction to
end future interference costs the defendant more than damages for future in-
terference. Is this fact generally true or just a special feature of this example?

C. Efficient Remedies
We mentioned that injunction is the usual remedy for breach of a property right.

We would like to explain this generalization, as well as exceptions to it, in terms of ef-
ficiency. The preceding example showed that damages and injunctions are equally effi-
cient remedies when transaction costs equal zero. Consequently, differences in
efficiency must depend on transaction costs. If transaction costs are so high as to pre-
clude bargaining, then the more efficient remedy is damages, not injunctions.

The reason that damages are more efficient than injunctions when transaction costs
preclude bargaining is easy to see from the example of the laundry and electric com-
pany. If damages perfectly compensate the laundry, its profits remain the same (specifi-
cally, $300) regardless of whether the electric company pollutes. So, the laundry is
indifferent between the damage and injunction remedies (assuming no bargaining).
Under the damage remedy, the electric company can pollute and pay damages, or it can
abate and not pay damages. Its profits increase from $500 to $800 when it pollutes and
pays damages, rather than abating. In contrast, an injunction (with no bargaining) re-
moves this choice. Specifically, the injunction forces the electric company to abate, in
which case its profits are $500. In general, when transaction costs preclude bargaining,
a switch in remedy from injunction to compensatory damages makes the victim no
worse off, whereas the injurer may be better off and cannot be worse off. In the exam-
ple of the laundry and electric company, a switch makes the electric company strictly
better off. According to Table 4.5, the noncooperative solution yields $800 to the elec-
tric company under a damage remedy and $500 under an injunction, whereas the laun-
dry enjoys $300 in either case.

We have explained the superiority of the damages remedy when transaction costs
are high. What about the converse proposition? Are injunctions the superior remedy

100 C H A P T E R 4 An Economic Theory of Property

when transaction costs are low? The traditional answer, which we will explain, is
“Yes.” Earlier we noted that bargaining tends to succeed when the legal rights of the
parties are clear and simple. Injunction is traditionally regarded as clearer and simpler
than damages, because the determination of damages by courts can be unpredictable.
To illustrate, it is difficult for a court to assign monetary value to the damage caused by
the Windsong satellite’s straying into the orbit of Orbitcom’s satellite in Example 2.
Similarly, it is difficult for a court to assign monetary value to the damage caused by
the intrusion of Potatoes’s house onto 2 feet of Parsley’s land in Example 5. In contrast,
the right to an injunction gives the parties a clear position from which to bargain. In the
course of bargaining, they may establish the value of the damage themselves. Thus, the
traditional argument concludes that the injunctive remedy is more efficient than dam-
ages when the parties can bargain with each other.

We have reached the conclusion of a famous article by Judge (then Professor)
Guido Calabresi and A. Douglas Melamed,20 who proposed the following rules for de-
termining the best remedy for violating a legal right:

Where there are few obstacles to cooperation (that is, low transaction costs), the more
efficient remedy is to enjoin the defendant’s interference with the plaintiff’s property.

Where there are obstacles to cooperation (that is, high transaction costs), the more
efficient remedy is to award compensatory money damages.

Most property disputes involve small numbers of contiguous landowners. Communi-
cation costs are low; the parties can monitor conformity to their agreements; and neigh-
bors take a long-run view towards each other, which limits opportunism and strategic
behavior. Bargaining is likely to be successful in these circumstances. According to the
preceding prescription, the usual remedy in property disputes ought to be injunctive re-
lief, and that is the law in fact.

Some property disputes, however, involve large numbers of people. As the num-
bers increase, communication costs rise, monitoring becomes difficult, and short-
sighted behavior increases. Private bargaining is unlikely to succeed in disputes
involving a large number of geographically dispersed strangers, such as disputes over
nuisances like air pollution and the stench from the feedlot in Example 3. According to
the preceding prescription, the usual remedy in nuisance suits with large numbers of
people should be damages. Chapter 5 explains that some courts have followed this prin-
ciple and others have not.

The two preceding rules constitute the “traditional prescription” in law and eco-
nomics to choose between damages and injunctive remedies. In most circumstances,
the traditional prescription suffices, but more careful thinking about information has
refined it. When a person’s activity spills over and affects other property owners, the

20 Calabresi & Melamed, Property Rules, Liability Rules, and Inalienability: One View of the Cathedral, 85
HARV. L. REV. 1089 (1972). As the title indicates, the authors consider a third method of encouraging the
efficient use of property—inalienability, the forbidding of a bargaining solution to the use of a property
right. We discuss the efficiency of that method briefly in the next chapter.

V. How Are Property Rights Protected? 101

21 The court knows the relative values of the entitlement if the unobservable elements of individual valua-
tions correlates positively with the observable elements. See Louis Kaplow & Steven Shavell, Property
Rules Versus Liability Rules: An Economic Analysis, 109 HARV. L. REV. 715 (1996). But see Ian Ayres &
Paul Goldbart, Correlated Values in the Theory of Property and Liability Rules, 32 J. LEGAL STUD. 121
(2003) (rejecting the correlated values claim—that “liability rules cannot harness private information when
the disputants’ values are correlated”).

court needs different information depending on whether its remedy is damages or in-
junction. When transaction costs obstruct bargaining, creating efficient incentives by
awarding damages requires the court to measure the harm correctly. If the court mis-
measures the harm, damages will be set too high or too low, which will distort the in-
jurer’s incentives. Chapter 6 explains this point in detail.

Alternatively, when transaction costs obstruct bargaining, creating efficient incen-
tives requires the court to know which party values the right the most in order to decide
between an injunction and no injunction.21 If the electric company values the right to
pollute more than the laundry values the right to be free from pollution, then the court
should allow the electric company to pollute and refuse the laundry’s request for an in-
junction. Conversely, if the laundry values the right to be free from pollution more than
the electric company values the right to pollute, then the court should grant the laun-
dry’s request for an injunction against the electric company’s pollution.

In sum, when transaction costs obstruct bargaining, what the court should do de-
pends on what it knows. The court must know the absolute value of the harm caused by
a spillover in order to provide efficient incentives by a damage remedy. The court needs
to know the relative value of the spillover in order to achieve efficiency by the injunc-
tive remedy. Now we can restate the first prescription’s refinement:

When transaction costs preclude bargaining, the court should protect a right by an in-
junctive remedy if it knows which party values the right relatively more (even if it
does not know how much either party values the right absolutely). Conversely, the
court should protect a right by a damage remedy if it knows how much one of the par-
ties values the right absolutely (even if it does not know which party values the right
relatively more).

The second prescription—award an injunction when low transaction costs permit
bargaining—also requires qualification in light of problems of information. This pre-
scription assumes that voluntary exchange of a right occurs more easily when it is pro-
tected by an injunction, because the injunctions are simpler and clearer than damages.
While this is usually true, it is not always so. In bargaining, what matters is costs, not
physics. No matter how clear the injunction, the cost of complying with it may be un-
clear. To lubricate bargaining, each party needs to know the other’s threat value or go-
it-alone value. Injunctions do not solve the problem that private information about costs
and values inhibits bargaining. To illustrate, the injunction for the electric company to
stop polluting is clear, but the cost to the electric company of complying, which may or
may not be clear to the electric company, is unclear to the laundry.

The truth is more equivocal than the traditional analysis suggests. With the injunc-
tive remedy, the obstacle to private agreement includes the plaintiff’s uncertainty about

102 C H A P T E R 4 An Economic Theory of Property

the defendant’s costs of complying with a court order. Conversely, with the damage
remedy, the obstacle to private agreement includes the defendant’s uncertainty about
the money value of the plaintiff’s harm.22

QUESTION 4.13: Use the theory of transaction costs to justify protecting the
following rights by injunction or damages:

a. A landowner’s right to exclude from his property a neighbor’s gas line.
b. A new car owner’s right to have her car’s defective transmission replaced

by the seller.
c. A homeowner’s right to be free from air pollution by a nearby factory.
d. A spouse’s right to half the house on divorce.

QUESTION 4.14: Suppose that two people choose to litigate a dispute.
Should the law presume that if two parties are prepared to litigate, transaction
costs must be high, and therefore the court should choose damages as the rem-
edy, not an injunction?

Web Note 4.2

There has been a surprising amount of recent scholarship on the Calabresi-
Melamed contention about the efficiency of remedies. We discuss much of
that literature on our website, including looking at the empirical literature on
whether the issuing of injunctions is typically followed by bargaining.

VI. What Can Be Privately Owned?—Public
and Private Goods23

In this section we turn to another fundamental question of property law: should
property rights be privately or collectively held? First, we use the economic distinction
between public and private goods (developed in Chapter 2) to differentiate those re-
sources that will be most efficiently used if privately owned from those that will be
most efficiently used if publicly owned.

Most examples of property that we have discussed thus far in this book are what
economists call “private goods.” Goods that economists describe as purely private have
the characteristic that one person’s use precludes another’s: For example, when one per-
son eats an apple, others cannot eat it; a pair of pants can be worn only by one person at

22 Taking these arguments into account leads to a more convincing version of the second rule:
Where there are few obstacles to cooperation (i.e., low transaction costs), the more efficient rem-
edy is the award of an injunction when the plaintiff can estimate the defendant’s compliance costs
more readily than the defendant can estimate the plaintiff’s damages.

23 Before reading this section, you may find it helpful to review the material on public goods in Chapter 2.

VI. What Can Be Privately Owned?—Public and Private Goods 103

a time; a car cannot go two different directions simultaneously; and so forth. These
facts are sometimes summarized by saying that there is rivalry in the consumption of
private goods.

The polar opposite is a purely public good, for which there is no rivalry in con-
sumption. A conventional example of a public good is military security in the nuclear
age. Supplying one citizen with protection from nuclear attack does not diminish the
amount of protection supplied to other citizens.

There is also another attribute that distinguishes private and public goods. Once
property rights are defined over private goods, they are (relatively) cheap to enforce.
Specifically, the owner can exclude others from using them at low cost. For example, a
farm can be fenced at relatively low cost to exclude trespassing cattle. With public
goods, however, it is costly to exclude anyone from enjoying them. To illustrate, it is
virtually impossible to supply different amounts of protection against nuclear attack to
different citizens.

Having explained the private-public distinction in economics and law, we can now
relate them to each other. The relationship is very simple: Efficiency requires that pri-
vate goods should be privately owned and that public goods should be publicly owned.
In other words, efficiency requires that rivalrous and excludable goods should be con-
trolled by individuals or small groups of people, whereas nonrivalrous and nonexclud-
able goods should be controlled by a large group of people such as the state. Thus, the
distinction between private and public goods should guide the development of property
rules to answer the question, “What can be privately owned?”

We can explain the central idea, not the details, for this prescription. Being rival-
rous, private goods must be used and consumed by individuals, not enjoyed equally by
everyone. Efficiency requires the use and consumption of each private good by the
party who values it the most. In a free market, exchanges occur until each good is held
by the party who values it the most. Thus, the law can achieve the efficient allocation
of private goods by, for example, lowering bargaining costs by assigning clear and sim-
ple ownership rights. Once the state recognizes private property rights, the owner of a
private good can exclude others from using or consuming that right, except by the
owner’s consent. The owner’s power to exclude channels the use or consumption of pri-
vate goods into voluntary exchange, which fosters the efficient use of those goods. This
is an example of “lubricating bargaining.”

In contrast, the technical character of public goods obstructs the use of bargaining
to achieve efficiency. To illustrate, suppose that a particular city block is plagued by
crime and some residents propose hiring a private guard. Many residents will volun-
tarily contribute to the guard’s salary, but suppose that some refuse. The paying resi-
dents may instruct the guard not to aid nonpayers in the event of a mugging. Even so,
the presence of the guard on the street will make it safer for everyone, because mug-
gers are unlikely to know who has and who has not paid for the guard’s services.
Given these facts, there is not much that the payers can do to compel nonpayers to
contribute.

Those people who do not pay for their consumption of a public good are called
“free riders.” To appreciate this concept, imagine that a street car has an electric meter in
it and, in order to make the street car move, the riders must put money into the meter.

104 C H A P T E R 4 An Economic Theory of Property

The riders will realize that anyone who pays provides a free ride for everyone else.
Perhaps some riders will, nonetheless, put their full fare into the meter; some will put
some money in but not their full fare; and some will not put anything in at all. Because
of “free riders,” not enough money will be put in the meter, so the street car company
will provide fewer street cars than efficiency requires. In general, markets supply too
little of a public good because the private supplier cannot exclude users of it who do
not pay their share of the costs.

We have explained that private goods, which exhibit rivalry and exclusion, ought
to be privately owned, and that public goods, which exhibit nonrivalry and nonexclu-
sion, ought to be publicly owned. We illustrate this proposition as applied to land.
Some efficient uses of land involve a small area and affect a small group of people,
such as building a house or growing corn. “Housing” and “corn” are rivalrous goods
with low exclusion costs, so markets easily form for housing and corn. Other efficient
uses of land involve a large area and affect a large group of people. For example, the
use of an uncongested airspace by airplanes or the use of the high seas for shipping are
not rivalrous and exclusion is costly. Thus, airspace and the high seas are public goods.
As congestion increases from more planes and ships, governments impose rules on the
use of the air and seas.

These are examples in which private goods are privately owned and public
goods are publicly owned, as required for efficiency. There are, however, many ex-
amples of private goods that are publicly owned. Public ownership of a private
good typically results in its misallocation, by which we mean that it is used or con-
sumed by someone other than the person who values it the most. For example, leases
for grazing cattle on public lands may be granted to the friends of politicians.
Similarly, the officials who administer the leases may not monitor compliance
to prevent overgrazing, and the ranchers who overgraze the land may cause it to
erode. Much of the impetus for “deregulation,” which was a worldwide movement
in the 1990s, came from the realization that much government activity concerns
private goods where markets should be lubricated, rather than government intrud-
ing directly in the process of allocation. For example, the realization that trans-
portation by railroad, airplane, and barge are private services that should
be supplied by free markets has led to the dismantling of the Interstate Commerce
Commission, the Civil Aeronautics Board, and other regulatory agencies in the
United States.

One way to contrast private and public ownership is in terms of transaction costs.
Private ownership imposes various transaction costs of private enforcement and ex-
change. Public ownership imposes transaction costs in terms of public administration
and collective decision making. To illustrate the difference, consider two possible ways
to control air pollution from a factory. The private property approach is to grant each
property owner the right to clean air, protected by the remedy of compensatory dam-
ages. This method will result in many landowners suing for damages or bargaining to
settle out of court. Alternatively, the public property approach would declare that clean
air is a public good, and assign the task of air quality control to a government agency.
This method will result in political bargaining and regulations. From this perspective,
the choice between private and public ownership should depend on whether the costs

VII. What May Owners Do with their Property? 105

24 We are not, of course, suggesting that the current division of responsibility between public and private
providers of goods and services necessarily follows the rules we have just set down. That is, there are cur-
rent instances of the government provision or subsidization of private goods and of the private (under-)
provision of public goods. The extent to which these anomalies exist and why they persist are two of the
central concerns of the branch of microeconomic theory called “public choice theory.”

of private enforcement and exchange are more or less than the costs of public adminis-
tration and political bargaining.

In the next chapter we will continue developing these themes by discussing two
important questions: For what specific resources is private ownership more efficient
than public or communal ownership and vice versa? And under what circumstances
should government be allowed to take private property from citizens?24

QUESTION 4.15: If everyone has free access to a public beach, who, if any-
one, has the power to control the use of this resource?

QUESTION 4.16: Discuss how to adjust private and public property rights
to promote ecotourism in Africa.

VII. What May Owners Do with Their Property?
We used the theory of private and public goods to answer the question, “What can

be privately owned?” Closely related to the theory of public goods is the theory of ex-
ternalities, which we discussed in Chapter 2. Now we return to that theory in order to
answer the question, “What may owners do with their property?”

Legislation imposes many restrictions on what a person may do with his or her
property. But at common law there are relatively few restrictions, with the general rule
being that any use is allowed that does not interfere with other peoples’ property or
other rights. Indeed, we could say that common law approximates a legal system of
maximum liberty, which allows owners to do anything with their property that does not
interfere with other people’s property or other rights. The restriction of noninterference
finds justification in the economic concept of external cost. Recall that external costs
are those costs involuntarily imposed on one person by another. Because market trans-
actions are voluntary, externalities are outside the market system of exchange—hence
their name. For example, a factory that emits thick, cloying smoke into a residential
neighborhood is generating an externality. In Example 3 at the beginning of this chap-
ter, the stench from the cattle feedlot is an externality that interferes with Foster’s en-
joyment of her house. In Example 4, the development of Bloggs’s wetlands will
interfere with the town’s enjoyment of its rivers and streams. Notice that these types of
interference are like a public good in that they affect many property owners. There is,
as it were, no rivalry or exclusion from smelling the feedlot’s stench among Foster and
her neighbors. These forms of interference are thus like a public good, except they are
bad rather than good.

106 C H A P T E R 4 An Economic Theory of Property

We have already explained why markets cannot arise to supply public goods effi-
ciently. The same set of considerations explains why private bargaining cannot solve
the problem of externalities, or, as we called them in a previous section, public bads.
To illustrate, suppose that Foster had enough money to pay the feedlot to stop emitting
its stench. If she made this private deal with the feedlot, all of her neighbors would also
benefit but without having to pay for that benefit. This fact suggests that Foster will not
pay the feedlot to stop its malodorous activities. More generally, the free-rider problem
prevents private bargaining solutions to the problem of externalities or public bads.
Some form of legal intervention is called for. One possibility is a rule forbidding invol-
untary invasion, supported by provisions for remedies if that invasion takes place. We
have already noted how bargaining theory can help to design the form that remedy
should take, namely, the payment of compensatory money damages. An alternative
remedy that we will consider in the following chapter is regulation of the public bad or
external-cost-generating activity by an administrative agency.

By contrast, private bads may be self-correcting through private agreements
(recall the rancher-farmer example), so that there may be no need for an intrusive legal
solution. Instead, the courts can stand prepared to issue an injunction in the confident
expectation that they will seldom be required to do so.

VIII. On Distribution
We have developed an economic theory of property based on efficient ownership.

However, some critics of economics believe that property law should be based on dis-
tribution, not efficiency.

Some people think that government should redistribute wealth from rich to poor
for the sake of social justice, whereas other people think that government should avoid
redistributing wealth, allowing individuals to receive all the rewards of their hard work,
inventiveness, risk-taking, and astute choice of parents. Like the rest of the population,
economists disagree among themselves about redistributive ends. However, economists
often agree about redistributive means.

Given the end of redistribution, economists generally prefer to pursue it by the
most efficient means. For each dollar of value transferred from one group to another, a
fraction of a dollar is typically used up, as, for example, in administrative costs. The
most efficient means of redistribution uses up the least value to accomplish the transfer.
Chapter 1 illustrated this fact by the example of ice cream melting during its transfer
across the desert from one oasis to another. Another example is the percentage of dona-
tions that a charity spends on administrative costs. Many economists believe that redis-
tributive goals can be accomplished more efficiently in modern states by progressive
taxation than by reshuffling property rights. Besides avoiding waste, more efficient re-
distribution generates more support from the people who must pay for it. If the econo-
mists are right, redistribution for social justice should focus mostly on taxation and
expenditure, not property rights.

Progressive taxation and expenditure is usually more efficient than reshuffling
property rights to achieve redistribution for a variety of reasons. The most wasteful

VIII. On Distribution 107

25 Professor Coase made this argument in “Notes on the Problem of Social Cost” in THE FIRM, THE MARKET,
AND THE LAW (1988). In general, taxes and other government impositions finally fall on factors in rela-
tively fixed supply, such as land.

26 A fundamental principle in public finance is that taxes distort less when applied to a broad base rather than
to a narrow base. Distortion decreases with the breadth of the base because demand becomes less elastic.
To illustrate, the demand for food is less elastic than the demand for vegetables, and the demand for veg-
etables is less elastic than the demand for carrots. Income is a very broad base.

way to redistribute wealth is for courts to tilt trials in favor of the plaintiff or defen-
dant depending on who is poorer. If courts favor the poorer party in legal disputes,
each person prefers to avoid interacting with relatively poorer people whenever a law-
suit could arise. Thus, a person would want to avoid owning real estate in a neighbor-
hood occupied by people who are poorer than he is. Similarly, favoring the poorer
party in a contract dispute makes a person reluctant to do business with anyone who is
poorer than he is.

Several other reasons also make taxation superior to property law as a means of
redistribution. First, the income tax precisely targets inequality, whereas property law
relies on crude averages. To illustrate, suppose that the rule of law in a particular
county in Montana is “ranchers’ rights.” If ranchers are richer than farmers on aver-
age in this county, then changing the rule to “farmers’ rights” would redistribute
wealth toward greater equality. However, although ranchers are richer than farmers
on average, some farmers are undoubtedly richer than some ranchers. Changing the
property rights to favor farmers over ranchers will aggravate the inequality between
the rich farmers and poor ranchers. In contrast, progressive taxation will ameliorate
unequal incomes.

A second objection is that reshuffling property rights may not really have the dis-
tributive effects anticipated. To illustrate, suppose that both farmers and ranchers rent
their land from absentee owners. If property law shifts the cost of fencing from farmers
to ranchers, competition among landlords may cause them to adjust rents to offset the
change in costs. Specifically, the landlords who own farm land may increase the rent
charged to farmers, and the landlords who own ranch land may decrease the rent charged
to ranchers. Consequently, the reshuffling of property rights may not affect the distri-
bution of wealth between farmers and ranchers. Instead, the landlords who own farms
may gain and the landlords who own ranches may lose. In general, any change in the
value of land gets “capitalized” into rent. Consequently, the wealth effects of reshuf-
fling property rights in a world with zero transaction costs tend to fall on the owners of
land, not its users.25

In addition, there is another reason for the relative inefficiency of redistribution by
property law. Redistribution by property law distorts the economy more in the long run
than does progressive taxation. For example, if property law favors farmers over ranch-
ers, some rich ranchers may switch to farming to gain valuable legal rights. In contrast,
a comprehensive income tax precludes people from reducing their tax liability by
changing the source of their income.26 For these reasons and more, economists who fa-
vor redistribution and economists who oppose it can agree that property law is usually

108 C H A P T E R 4 An Economic Theory of Property

the wrong way to pursue distributive justice. Unfortunately, these facts are not appreci-
ated by many lawyers who have not studied economics.27

We have presented several reasons against basing property law on redistributive
goals. Specifically, we discussed imprecise targeting, unpredictable consequences, high
transaction costs, and large distortions in incentives. While the general principles of
property law cannot rest on wealth redistribution, special kinds of redistributive laws can
ameliorate these objections and blunt this criticism. An example is laws requiring em-
ployers to construct buildings that provide access to people in wheelchairs. If properly
designed, these laws can precisely target handicapped people in a predictable way, en-
forcement by private legal action can be inexpensive, and the distortion in incentives can
be modest. Designing such laws to produce these desirable outcomes, however, requires
more careful attention to the underlying economics than regulators typically show.

Conclusion
Property is a bundle of rights with incentive effects. Efficient property rights create

incentives to maximize a nation’s wealth in two different ways. First, property rights are
the legal basis of voluntary exchange, which achieves allocative efficiency by moving
goods from people who value them less to people who value them more. Second, prop-
erty rights are part of the law that makes owners internalize the social costs and benefits
of alternative uses of the goods that they own. Owners achieve productive efficiency by
balancing the social costs and benefits of what they do with what they own.

Suggested Readings

Bell, Abraham, & Gideon Parchomovsky, A Theory of Property, 90 CORNELL L. REV. 531 (2005).
Calabresi, Guido, The Pointlessness of Pareto: Carrying Coase Further, 100 YALE L. J. 1043

(1991).
Cooter, Robert, The Cost of Coase, 11 J. LEGAL STUD. 1 (1982).
Ellickson, Robert D., Property in Land, 102 YALE L.J. 1315 (1993).
ELLICKSON, ROBERT, ORDER WITHOUT LAW: HOW NEIGHBORS SETTLE DISPUTES (1991).
Lueck, Dean, & Thomas Miceli, Property, in A. MITCHELL POLINSKY & STEVEN SHAVELL, EDS.,

HANDBOOK OF LAW AND ECONOMICS, vol. 1 (2007).
Merrill, Thomas W., & Henry E. Smith, Optimal Standardization in the Law of Property: The

Numerus Clausus Principle, 110 YALE L.J. 1 (2000).
Merrill, Thomas W., & Henry E. Smith, What Happened to Property in Law and Economics?,

111 YALE L.J. 357 (2001).
Polinsky, A. Mitchell, Resolving Nuisance Disputes: The Simple Economics of Injunctive and

Damage Remedies, 32 STAN. L. REV. 1075 (1980).

27 An important technical conclusion in formal welfare economics (the Second Fundamental Theorem of Welfare
Economics) reinforces the general point made in the text—namely, that efficiency and equity are separable.
With specific reference to property law, that conclusion can be read to say that property law should seek to al-
locate and enforce entitlements so that a society uses resources efficiently and should then use the tax-and-
transfer system to achieve distributive equity. See, for example, Steven Shavell, A Note on Efficiency v.
Distributional Equity in Legal Rulemaking: Should Distributional Equity Matter Given Optimal Income
Taxation?, 71 AM. ECON. REV. 414 (1981), and Louis Kaplow & Steven Shavell, Why the Legal System Is Less
Efficient Than the Income Tax in Redistributing Income, 23 J. LEGAL STUD. 667 (1994).

PHILOSOPHERS GENERALLY PERCEIVE property to be an instrument for pursuing fun-
damental values. Some philosophers of property have concentrated on its ability
to advance values such as utility, justice, self-expression, and social evolution.

These traditions of thought have influenced the law. This appendix introduces the
reader to four of these traditions and relates them to the economic analysis of property.

1. Utilitarianism
Utilitarians measure the value of a good or an act by the net pleasure or satisfac-

tion that it creates. For utilitarians, the purpose of the institution of property is to max-
imize the total pleasure or satisfaction obtained from material and other resources.
Bentham thus defines property as an expectation of utility: “Property is nothing but a
basis of expectation; the expectation of deriving advantages from a thing, which we
are said to possess, in consequence of the relation in which we stand toward it.”28 The
objective of maximizing total utility constitutes a standard against which property
rules can be evaluated. In our examples at the beginning of the chapter, each of the
disputes could be resolved on utilitarian grounds by establishing a legal rule that seeks
to maximize the sum of utilities or pleasure of society as a whole.

The utilitarian approach makes a person’s claim to property tentative. It can be
taken from him in principle if the beneficiaries of the expropriation gain more in
utility than the owner loses. Suppose, for example, that a young son is living with
his aged parents in their home. On utilitarian grounds, the young son may be ex-
cused for throwing the parents out of the home if their loss in utility from being dis-
possessed is less than his gain in utility from having them out of the house. Critics
of utilitarianism have often wondered whether the theory makes ownership too ten-
tative. Isn’t ownership more than an expectation? Do we really think that a person
could be rightfully deprived of his property just because the loss is more than offset
by the gain to others?

This objection to the utilitarian theory of property applies with equal force to the
conventional economic theory that holds that the purpose of property is to maximize
wealth. Isn’t ownership more than a right to a stream of income? Do we really think

109

The Philosophical Concept
of Property

28 JEREMY BENTHAM, THEORY OF LEGISLATION: PRINCIPLES OF THE CODE 111–113 (Hildreth ed. 1931).

APPENDIX

CHAPTER 4

that a person could be rightfully deprived of her property just because the loss of wealth
is more than offset by the gain in wealth to others?

2. Distributive Justice
Another philosophical approach to property law emphasizes property law’s ability

to achieve distributive justice, rather than pleasure or satisfaction. Aristotle, for exam-
ple, held that a conception of distributive justice is implicit in various forms of social
organization. For Aristotle, the principle of justice is different for different societies,
but it is appropriate for each type of society to promote its own conception of distribu-
tive justice through its constitution and laws, including its notion of property rights. He
argued that a democracy will favor an equal distribution of wealth, whereas an aristoc-
racy (the form preferred by Aristotle) will favor the distribution of wealth according to
the virtues of various classes. In Aristotle’s conception, it is just that aristocrats receive
an unequal share of wealth because they use it for more worthy ends than do others.

From the Aristotelian conception of democratic equality we might infer a policy of
redistributive justice whereby the valuable assets of society are periodically redistrib-
uted so as to achieve a roughly equal distribution of that property. In general, this sort
of redistribution would favor the poor and penalize the wealthy. On the other hand,
from the Aristotelian justification of aristocratic inequality we might infer the polar-
opposite policy of redistributive justice whereby the assets of society would be periodi-
cally redistributed to the aristocrats. To the extent that the aristocracy and the wealthy
are the same group, this redistribution of property would favor the rich and penalize the
poor. In either case, these notions of distributive justice make property claims as tenta-
tive as they were under utilitarianism and, therefore, open to the same criticisms.

There is another school of philosophical thought relating to distributive justice and
property that emphasizes a just process for defining and enforcing property rights
rather than a just outcome or end result in the distribution of wealth from property.29

According to one version of this theory, any distribution of wealth is just provided that
it starts from a just initial distribution of resources and achieves the final distribution
by voluntary exchange. In practice, this means that the process of voluntary market ex-
change is just and that ownership claims are most justly established and enforced in an
unfettered market in which there is free and perfect competition. In Nozick’s memo-
rable rephrasing of Marx, “From each as he chooses; to each as he is chosen.”
Whatever distribution of wealth results from this just process is also just. Thus, accord-
ing to this theory, redistributing property to dilute the effects of competition is unjust.

Several criticisms have been made of this notion of distributive justice. The most
telling criticism is that the competitive process can lead to a multitude of distributive
outcomes, from one in which each individual has an equal share to one in which one
individual has 99 percent of the property and everyone else divides up the remaining
1 percent. All of the outcomes are efficient. But clearly not all of them are equitable
or just. The notion of the competitive process as distributive justice is not a sufficient

110 C H A P T E R 4 An Economic Theory of Property

29 The most forceful modern statement of this view is in R. NOZICK, ANARCHY, STATE, AND UTOPIA (1974).

guide to designing rules of property law. At a minimum, there must be an additional,
independent standard by which to appraise various initial endowments of property.

3. Liberty and Self-Expression
Besides utility and distributive justice, another value that may underlie property

law is liberty. Private property is a precondition for markets, and markets are a decen-
tralized mechanism for allocating resources. Most markets can, and do, operate with-
out extensive government interference or supervision. The practical alternative to
markets in the modern economy is some form of government planning. Government
planning involves centralizing power over economic matters in the hands of state offi-
cials. Control over economic life provides officials with leverage that can be used to
control other aspects of life, whereas private property creates a zone of discretion
within which individuals are not accountable to government officials. Private property
has thus been viewed by some philosophers as a bulwark against the dictatorial au-
thority of governments.30 It has been argued, for example, that capitalism was deliber-
ately invented to thwart absolutism by depriving the king of economic power. The
U.S. Constitution was probably drafted with this idea in mind.

Another connection between property and liberty focuses on individual self-
expression. Hegel stressed the idea that people, through their works, transform nature
into an expression of personality, and, by doing so, perfect the natural world. A painter
takes materials in no particular order and rearranges them into a work of art. By invest-
ing personality in work, the artist transforms natural objects and makes them the artist’s
own. It is difficult to imagine a system of property law that did not recognize this fact.
Thus, to encourage self-expression, the state needs to recognize the creators’ rights of
ownership over their creations. Notice that this proposition extends beyond art to most
of the works of humans.

4. Conservatism and the Origins of Property
The philosophical theories discussed so far tend to regard the institution of property

as serving ultimate values, such as utility, distributive justice, or liberty. Another philo-
sophical tradition focuses not on the purposes of property but on its origins. To illustrate,
in medieval times there were many encumbrances and restrictions on the use and sale of
real estate. The common law of private property emerged from feudalism and acquired
its modern character by chipping away at these encumbrances on the marketability of real
property. Political conservatives like Burke and Hayek idealize forms of social order that,
like the common law of property, evolve over time in much the same manner as the myr-
iad species of life. Like organisms, social forms are, in this view, subject to the rules of
natural selection. The conservative philosophers condemn institutions imposed on us by
planners, engineers, politicians, and other societal decision makers for much the same
reasons that environmentalists condemn actions that interfere with an area’s environment.

4. Conservatism and the Origins of Property 111

30 This is a theme in THE FEDERALIST PAPERS (1786) and in the work of Friedrich Hayek (see, for
example, The CONSTITUTION OF LIBERTY (1972)).

IN THE PRECEDING chapter, we developed an economic theory of property rights and
remedies. We saw that property law creates a bundle of rights that the owners
of property are free to exercise as they see fit, without interference by the state or

private persons. Consistent with this freedom is a system of allocation by voluntary
exchange. Property law fosters voluntary exchange by removing the obstacles to
bargaining. When the obstacles to bargaining are low, resources will be allocated effi-
ciently. We used this framework and economic theory to answer the following four
questions that must be addressed by a theory of property law:

1. What can be privately owned?
2. How are ownership rights established?
3. What may owners do with their property?
4. What are the remedies for the violation of property rights?

To answer the first question, we distinguished between private and public goods, and
we claimed that the former should be privately owned. Private ownership is appropriate
when there is rivalry and exclusion in the use of goods. To answer the second question,
we presented a thought experiment to illustrate how property law encourages produc-
tion, discourages theft, and reduces the cost of protecting goods. According to this
thought experiment, people agree to establish property rights to share the benefits from
increased productivity. We answered the third question by developing the theory of
externalities, especially the connection between public bads in economics and nui-
sances in law. We noted that common law approximates a system of maximum liberty,
which allows any use of property by its owner that does not interfere with other peo-
ple’s property or protected rights. In answering the fourth question, we used bargaining
theory to conclude that the injunctive remedy is preferred for private bads with low
transaction costs for private bargaining. Conversely, the damage remedy is preferred
for public bads with high transaction costs that preclude private bargaining.

These answers given in the previous chapter are very general. In this chapter, we
reexamine these questions in detail, with concrete applications. The topics are organ-
ized roughly according to the four fundamental questions of property law.

I. What Can Be Privately Owned?
The economic distinction between public and private goods characterizes two ideal

types. Although reality is never ideal, understanding these ideal types increases your

112

5 Topics in the Economics
of Property Law

understanding of laws governing real goods. In this section we discuss the application
of property law to information, which has some features of a public good. Four princi-
pal areas of law create property in information and are called “intellectual property law.”
The patent system establishes ownership rights to inventions, processes, and other tech-
nical improvements. The copyright system grants ownership rights to authors, artists,
and composers. The trademark system establishes ownership for distinctive commercial
marks or symbols that uniquely identify an individual’s or organization’s output. The
area of law known as trade secrets deals with business practices in which commercial
enterprises have a property interest. (We discuss trade secrets briefly below and more
extensively on our website.) After discussing the economics of information, we will turn
to its application to the law of patents, copyright, and trademark. Then we will turn to a
new section on the ownership of organizations, specifically corporations.

A. Information Economics
Five thousand years ago people slept under grass roofs, covered themselves with

skins, and fastened sharp stones on sticks to throw at animals. An American Indian
friend of Professor Cooter said, “My father lived in the stone age, I grew up in the iron
age, and I’m dying in the computer age.” The technical innovations that drove these
changes have accelerated. Since the industrial revolution, innovation has caused wealth
to grow at compound rates. Compounded over a century, a 2 percent annual growth rate
increases wealth more than six times; a 5 percent annual growth rate increases wealth
more than 130 times; and a 10 percent annual growth rate increases wealth almost
14,000 times.

This section concerns some laws that promote innovation and cause compound
growth. To understand how these laws affect growth, we must first explain the basic
economics of innovations, beginning with the effects of innovation on welfare. An
economic innovation provides a better way to make something or something better to
make. A better way to make something lowers its cost, so the supply curve shifts down
and to the right. This shift causes the price of the good to fall for consumers. The
amount of their gain is measured by the increase in consumers’ surplus in the market
for the cheaper good. Similarly, finding something better to make creates a new good
that some consumers buy.

Consumers benefit from the fall in the price of a good that they buy or from the
introduction of a new good. In addition, innovations can make whole industries ap-
pear, disappear, or restructure. Only historians remember the American Ice Trust,
which was one of America’s largest corporations in 1900. By changing wages and
employment, innovation disrupts communities, causing some to grow and others to
wither. The mechanization of agriculture in the U.S. emptied the countryside in the
early twentieth century and left vacant buildings boarded shut in small towns.
Although many agricultural workers moved to the city for higher wages, a plough-
man with a team of horses who remained in the countryside found few employers
who valued his skill. In Europe, the industrial revolution shoved the nobles with large
estates out of the centers of political power. Joseph Schumpeter appropriately called
innovation “creative destruction.”

I. What Can Be Privately Owned? 113

114 C H A P T E R 5 Topics in the Economics of Property Law

Most societies value the gains from faster growth more than they fear its destructive
effects. Property law can help to secure rapid economic growth. To understand why, we
must shift from consumers and workers to companies. A company that innovates gains a
competitive advantage, which immediately creates extraordinary profits. Extraordinary
profits reward the innovator for the resources and effort devoted to a very risky activity.
In the long run, however, competition causes the innovation to diffuse, and many com-
panies make use of it. When the innovation diffuses fully, the innovator loses its com-
petitive advantage, and its profits fall to the ordinary level. When diffusion is complete,
the economy reaches a new equilibrium whose benefits diffuse even more broadly than
the innovation.

In this life cycle of an innovation, the innovation causes a disequilibrium, and the
innovator earns extraordinary profits as long as it persists. The reward for innovation
thus depends on how long the disequilibrium persists. A quick move to equilibrium
gives little reward to the innovator for the resources that it invested and the risk that it
assumed. Without legal intervention, competition can quickly destroy the profits from
innovation, which results in too little innovation.

To see why, we must understand some elements of the economics of information.
Everyone with a television or computer buys information, but information differs from
other commodities like oranges or razor blades. What special problems exist in defin-
ing property rights and establishing markets in information? Information has two char-
acteristics that make transactions in information different from transactions in ordinary
private goods. The first characteristic is credibility, which we discuss in Chapter 9. The
second characteristic, which we discuss now, is nonappropriability. Information is gen-
erally costly to produce and cheap to transmit.

To illustrate, popular music is costly to make and recordings are cheap to copy.
The instant the producer sells information to the buyer, that buyer becomes a poten-
tial competitor with the original producer. For example, when someone buys a com-
pact disk recording at a music store, the buyer can copy the disk immediately and
resell it to others. Furthermore, the reseller bears only the cost of transmission, not
the cost of production. Thus, resellers who pay for transmission undercut producers
who pay for production. Consumers try to “free ride” by paying no more than the
cost of transmission.

The fact that producers have difficulty selling information for more than a fraction
of its value is called the problem of nonappropriability. To illustrate, Hong Kong shops
traditionally resell American software at the cost of a diskette. Producers use various
devices to try to protect their products against appropriation, such as writing computer
programs that are hard to copy. (The industry calls this “digital rights management.”)
But for every program obstructing copying, there is a hack.

Consider the connection between nonappropriability and public goods. Information
contains ideas. One person’s use of an idea does not diminish its availability for others
to use. Thus, information use is nonrivalrous. Excluding some people from learning
about a new idea can be expensive, because the transmission of ideas is so cheap. Thus,
information is nonexcludable. These are the two characteristics of public goods identi-
fied in Chapter 2. Nonappropriability of information is essentially the same problem as
non-excludability for public goods.

I. What Can Be Privately Owned? 115

Because of these problems, private markets often undersupply public goods.
Similarly, economists who developed the original economics of information concluded
that a private market would provide less than the efficient amount of information.
These theoretical considerations suggest that an unregulated market will undersupply
creative works that embody ideas, such as science, inventions, books, and paintings.
The problem has four different remedies that we will describe.

The first remedy is for the state to supply or subsidize art and science, especially
basic research. Thus, the state owns or subsidizes many universities. More relevant to
this book are subsidies for trials. In many civil law countries such as Mexico and Chile,
the citizens have a right to use the courts for free. In the United States litigants are as-
sessed court fees, but fees fall far short of court costs, so trials are subsidized. In
Chapter 10 we will argue that common law precedents are a valuable stock of ideas.
From this fact we will conclude that U.S. courts should stop subsidizing the resolution
of private disputes and continue subsidizing the creation of legal precedents.

The second remedy is charitable contributions. A great tradition in the United
States and some other countries (but not all) is the expectation that wealthy people will
make substantial voluntary contributions to the arts and sciences. Besides social norms
requiring such gifts, the tax system in the United States allows for the deduction of
charitable donations from the donor’s taxable income. In practice, the charitable deduc-
tion means that donors contribute roughly two-thirds of the donation’s value and the
U.S. Treasury contributes the other one-third. Other countries such as Switzerland do
not allow such deductions, apparently because of sentiment that the state, not the rich,
should control the arts and sciences. Charity, however, enjoys this significant advan-
tage over government: donors monitor the use of their money by their favorite charities
more carefully than taxpayers monitor the government’s use of taxes, and monitoring
reduces waste.

The third remedy, broadly described as trade secrets protection, comes from con-
tract and tort law. An employee or contractor with a Silicon Valley company is rou-
tinely required to sign a non-disclosure agreement (NDA). In an NDA, the employee or
contractor promises not to disclose any of the company’s secrets. For example, the em-
ployee or contractor promises not to speak or write about the company’s machinery,
equipment, research, or business practices. Trade secrets protection ideally prevents the
transmission of information and allows its producer to appropriate its value.

Trade secrets laws, however, have weaknesses that impair their effectiveness.
Assume that inventor A employs person B who signs an NDA, and then person B leaks
A’s secrets to company C:

A

Inventor

Contract
includes NDA

B

Employee

Transmits
information

C

Third Party

A has a contract with B and no contract with C. Because C has no contractual
obligations to A (in legalese, A and C do not have “privity” of contract), A has lim-
ited legal powers to prevent C from using A’s trade secrets or transmitting them to

116 C H A P T E R 5 Topics in the Economics of Property Law

others. If C knew or had reason to know that B violated the NDA, then A could sue C. If
C induced B to violate the NDA, then A could sue C. But if C did not know, or have rea-
son to know, or induce B’s breach of contract with A, then C did nothing wrong in receiv-
ing the information. Furthermore, if the information has thoroughly leaked and become
common knowledge in the industry, anyone can use it for free, even if they know that the
information originally escaped into the public sphere by breach of contract.

Recent survey research concludes that trade secrets protection is not very effective
in Silicon Valley. In reality, employees change jobs frequently in Silicon Valley, and
they carry many of the old firm’s secrets to the new firm. In fact, many Silicon Valley
employees do not understand when they breach trade secrets laws, partly because these
laws depart so far from business practices in Silicon Valley.

The fourth remedy, which usually supplements trade secrets protection, is
intellectual property law. In addition to non-disclosure agreements with his employees,
associates, and business customers, inventor A may try to obtain a patent, copyright, or
trademark. If his application succeeds, A will have property rights in the information
that he produced. For this reason, these three bodies of law belong to the study of
intellectual property, which is our next topic.

Web Note 5.1

We discuss the burgeoning law-and-economics literature on trade secrets on
our website.

B. Intellectual Property
As with real estate, ownership of the mind’s products implies the right to exclude

others from using them. When intellectual property rights are effectively enforced, the
owner of a new computer chip or novel can use the power of exclusion to extract a price
from other users. The price rewards the creator, which results in more innovations and
faster growth—a form of “dynamic efficiency.”

After making an innovation, disseminating it allows more people to enjoy its
advantages. Intellectual property rights can also increase dissemination. Without prop-
erty rights, the innovator may try to keep the innovation secret in order to profit from it.
Thus, Renaissance Venetians carefully guarded the secrets of glassmaking, and
Shakespeare carefully guarded the texts of his plays so that only his company could
perform them. With effective intellectual property rights, however, the innovator need
not fear that others will steal the innovation. Instead of keeping it secret, the owner can
disseminate it and charge fees for its use, such as licensing fees for patents or perform-
ance fees for plays. Replacing secrecy with property increases dissemination, which
results in wider use—an increase in “static efficiency.”

Although secure intellectual property rights cause the owner to disseminate an
innovation, dissemination usually stops short of the point required for static efficiency.
Monopoly theory explains why. A valuable invention creates a better product or a better
way to make an old product. If the invention has no close substitutes, granting a patent

I. What Can Be Privately Owned? 117

or copyright creates “monopoly power,” which means that the seller can raise the price.
To maximize profits, the owner-monopolist sets the user fee too high for social effi-
ciency, so use is too low. Thus, intellectual property law may result in less dissemina-
tion of an innovation than required for static efficiency.

Patents and copyright may be temporary monopolies that can vary in breadth and
duration. Narrowing the breadth or shortening the duration of intellectual property
rights often decreases monopoly profits and increases dissemination. To illustrate, as-
sume that one person writes a novel and another adapts it for a movie. Narrow copy-
right law gives the novelist ownership of the novel and the adapter ownership of the
movie rights. In contrast, broad copyright law gives the novelist ownership of the novel
and the movie rights, which are an example of what are called “derivative works.”
Similarly, a patent on a computer chip can last different lengths of time in different
countries. Starting from narrow, short intellectual property rights, broadening and
lengthening them rewards the creator and encourages more innovation. If the innova-
tion can be kept secret, then broadening and lengthening the intellectual property rights
rewards dissemination by increasing user fees. Thus, increasing incentives for creation
also increases incentives for dissemination, at least up to a point. Beyond this point,
however, broadening the scope or duration of the creator’s property rights increases
monopoly power, which rewards creation and reduces dissemination. Thus, incentives
for creation and dissemination trade off. (Later we explain that increasing the scope or
duration of the creator’s property rights still further may eventually reduce creation and
dissemination.)

To appreciate the problem of dissemination, consider bridge tolls. Efficiency re-
quires the toll to equal the marginal cost of crossing the bridge. The cost of allow-
ing another motorist to cross an uncongested bridge is approximately zero, so the
optimal toll is approximately zero. If the optimal toll is not zero, someone who val-
ues crossing the bridge will fail to do so, which is a waste. Suppose the toll is $1. A
person who is willing to pay $.75 will not cross, so the toll destroys $.75 in benefits
that could have been created at no cost. (The conclusion is different for a congested
bridge, where increased congestion is the cost of allowing another motorist to
cross.) Similarly, the cost of allowing another person to use a patented computer
program or music recording is approximately zero, so the optimal user fee is ap-
proximately zero. However, the fee that maximizes profits for the owner is much
larger than zero. Thus, intellectual property may result in too-high user fees and too-
low dissemination.

The innovation-diffusion tradeoff causes major trade tensions in the contempo-
rary world. The world’s developed countries create far more innovations that result in
patents or copyrights than developing countries do. The developed countries, conse-
quently, focus on the benefits of strong intellectual property rights that protect their
creators. In contrast, the developing countries benefit from wide diffusion of technol-
ogy at low cost. The developing countries, consequently, lack enthusiasm for enforc-
ing intellectual property rights that raise prices to their consumers. Thus, Microsoft
wants China to suppress illegal copying of its software, and China apparently lacks
enthusiasm for this effort. The net result is that the latest Microsoft software sells in
Hong Kong street markets for the cost of a diskette, and the U.S. threatens to sue

118 C H A P T E R 5 Topics in the Economics of Property Law

China in the World Trade Organization.1 These tensions should ameliorate as China
finds that weak intellectual property law retards its own development of software and
other creative industries.

Intellectual property law confronts the innovation-dissemination tradeoff and
resolves it somewhat differently in each of its three principal areas—patents, copy-
rights, and trademarks. Intellectual property law, however, is a historical accretion
that developed without a scientific basis. Only recently has property law come un-
der economic analysis. Even today, however, available economic analysis is insuffi-
cient to the task. The usual technique of economic analysis involves comparing
equilibria with fixed technology (“static equilibrium analysis”), whereas intellectual
property law requires an analysis of innovation and changing technology (“growth
theory”). Improvements in the economics of information will no doubt produce new,
better critiques of intellectual property law. In the meantime, the economic analysis
of intellectual property law must proceed with the tools at hand. Besides inadequate
scientific tools, intellectual property law aligns poorly with economic efficiency be-
cause the legislators respond to politically powerful special interest groups who care
about their own profits more than the nation’s wealth. The development of high
technology industries challenges both economic theory and the law. Almost all
questions regarding intellectual property law are open. This fact makes the subject
both exciting and confusing.

1. Patents: Broad or Narrow? To appreciate the history of patent law, con-
sider its evolution. European patents for inventions began in the Republic of Venice
in 1474 and were formalized in England in the Statute of Monopolies in 1623.
Article I, Section 8 of the U.S. Constitution gives Congress the power “to promote
the progress of science and useful arts, by securing for limited time to authors and
inventors the exclusive right to their respective writings and discoveries.” To put this
power into action with respect to patents, the U.S. Congress passed America’s first
patent law in 1790, which was revised in 1793, 1836, 1952, and 1995. To secure an
exclusive right to an invention, the inventor must submit an application to the U.S.
Patent Office establishing that the invention is for a “new and useful process, ma-
chine, manufacture, or composition of matter, or [a] new and useful improvement
thereof.” (35 U.S. Code 101.) The invention must be “non-obvious,” must have
“practical utility” (a characteristic that is more or less presumed for all applicants),
and must not have been commercialized or known to the public for more than a year
before the date of application. A patent examiner—a government official who is,
ideally, a lawyer with a strong scientific background—must decide whether to grant
the patent. Approximately three-fourths of all applications are granted by the Patent
Office. Throughout the 1970s, between 70,000 and 80,000 patents were granted per

1 The Agreement on Trade Related Aspects of Intellectual Property, or TRIPS, applies to all members of the
World Trade Organization. Intellectual property rights are also enforced internationally through the World
Intellectual Property Organization, or WIPO.

I. What Can Be Privately Owned? 119

year.2 But in the 1990s patent applications and the number of patents granted in the
United States exploded to nearly 150,000 per year. The successful applicant now re-
ceives a 20-year monopoly on the use of the invention.3 No one can use the inven-
tion except by its owner’s consent. Others who wish to use the invention must
purchase the right to do so from the patent-holder. The holder may, at his or her dis-
cretion, license the use of the patent in exchange for the licensee’s payment of a fee
known as a royalty.

If a patent-holder believes that another is using his patent without permission, he
or she may bring an action for infringement and seek both injunctive and legal relief.

Web Note 5.2

See our website for more on recent developments in patent laws in the United
States and other nations, including speculation on the causes of the tremen-
dous upsurge in the number of patents in the 1990s and early 2000s.

An inventor who applies for a patent risks more than lawyers’ fees. The informa-
tion in the application is accessible to the public. If the application fails, competitors
will be able to freely use the invention described in the application. If the application
succeeds, competitors will have a precise description of the invention, so they can try
to emulate it without trespassing on the patent (“engineer around the patent”). For these
reasons, some inventors prefer to rely on trade secrets protection and not apply for a
patent. More typically, however, an inventor relies on both trade secrets laws and
patents to protect his intellectual property.

Patents create an exclusive property right in an invention with two dimensions:
duration and breadth. “Duration” refers to the number of years between a patent’s regis-
tration and its expiration. For example, most U.S. patents last for 20 years from the date
of application. “Breadth” refers to how similar another invention can be without infring-
ing on the patent for the original invention. To illustrate, the Rubik’s Cube is a popular
puzzle in which each of the six sides of the cube are divided into a 3 ” 3 grid, and each
of the cells in the grid is colored. The object of the game is to manipulate the cube in
order to align rows of same-colored cells. An American court ruled that the Rubik’s
Cube did not infringe an earlier patent by Moleculon for a similar game using a 2 × 2
grid.4

2 Of those issued between 1971 and 1975, 51 percent were granted to domestic corporations, 23 percent to
foreign corporations and governments, 2 percent to the U.S. federal government, and 23 percent to individ-
ual inventors. This distribution represents a trend in the century toward corporate ownership and away from
individual ownership of new patents. FREDERICK SCHERER, INDUSTRIAL MARKET STRUCTURE AND ECONOMIC

PERFORMANCE (2d ed. 1980).
3 In 1995, as part of the agreement establishing the World Trade Organization, the U.S. Congress changed

the patent life from 17 years from the date of approval to 20 years from the date of application. The change,
which brings the U.S. system into conformity with other national patent systems, arose from the approval
of the latest international trade agreement.

4 Moleculon Research Corp. v. CBS, Inc., 872 F.2d 407, 409 (Fed. Cir. 1989).

120 C H A P T E R 5 Topics in the Economics of Property Law

1a. Breadth An important policy question concerns the efficient breadth of a
patent. To understand the difference in incentive effects between narrow and broad
patents, contrast two inventors, two inventions, and two rules. Assume that two inven-
tors are contemplating investing in research on two inventions. The first invention
would improve oil-cracking processes, and the second invention would provide a sub-
stitute for lead in gasoline. The inventors expect the two inventions to be similar but
not identical. Under a broad rule, a single patent would encompass both inventions.
Because the party who makes the first invention receives exclusive rights to both inven-
tions, the party who makes the first discovery gets all of the profits, and the other party
gets nothing. Thus, the broad rule encourages fast, duplicative research. In contrast, un-
der a narrow rule, a separate patent would be required for each invention. The party
who makes the first invention would receive exclusive rights to it, and the party who
makes the second invention would have exclusive property rights to it. Thus, the nar-
row rule encourages slower, complementary research.

To appreciate this contrast between broad and narrow patents, consider a typical
relationship between research and development (R&D). Research sometimes yields a
pioneering discovery with no immediate commercial value, but with large commercial
potential. To realize its potential, a pioneering discovery must be developed and
“brought to market.” Development involves a series of small improvements. A patented
pioneering invention can be followed by a valuable application patented by another in-
ventor. In such cases, U.S. law has an interesting feature: Neither party can use the ap-
plication without the other’s permission. As long as both patents endure, the owner of
the application cannot use his patent without a license from the owner of the pioneer-
ing invention, and the owner of the pioneering invention cannot use the application
without a license from its owner. The result is that they have to negotiate with each
other and reach an agreement before anyone can use the application and make money
from it. U.S. patent law for pioneering inventions and applications creates an incentive
for each to bargain with the other.

These mutual rights get triggered when the subsequent invention is an application
of the prior invention. The legal question is how broadly the pioneering discovery ex-
tends over the follow-on inventions. Broad patents encourage fundamental research,
and narrow patents encourage development. Thus, suppose that an investment of
$100,000 in research yields a pioneering invention that has no commercial value.
Subsequently, an investment of $50,000 in development yields an improvement to the
pioneering invention that has commercial value of $1 million. If the law grants broad
patents, a patent for the pioneering invention would also cover the improvement, but if
the law grants narrow patents, separate patents would be required for the pioneering
invention and the improvement.

What breadth of patents is most efficient? If the social value of investment on fun-
damental research exceeds the social value of investment on developing applications,
then patents should be broadened. Conversely, if the social value of investment on
developing applications exceeds the social value of investment on fundamental
research, then patents should be narrowed.

In reality, questions of breadth are decided in law according to the “doctrine of
equivalents,” which refers to a series of court findings about how nearly equivalent

I. What Can Be Privately Owned? 121

5 See Westinghouse v. Boyden Power Brake Co., 170 U.S. 537, 572 (1898).
6 See Howard F. Chang, Patent Scope, Antitrust Policy, and Cumulative Innovation, 26 RAND J. ECON. 34

(1995). See also Robert P. Merges & Richard R. Nelson, On the Complex Economics of Patent Scope, 90
COLUM. L. REV. 839 (1990).

two inventions must be before finding patent infringement. This doctrine is obscure
and unpredictable. Courts have sometimes reasoned that an improvement with great
commercial value should not be interpreted as infringing on a pioneering invention
with little stand-alone value.5 After all, the improvement, not the pioneering inven-
tion, is what people really value.

Howard Chang, an economist-lawyer, has recently shown that this argument is
flawed for purposes of maximizing the social value of inventive activity.6 If the people
who do fundamental research receive the sale value of the pioneering invention, but
they do not receive any of the sale value of the commercial applications, there will not
be enough fundamental research. To see why, consider an analogy between pioneering
inventions and raising sheep. Sheep are sold for mutton and wool. Assume that the mut-
ton from a sheep is worth much more than the wool. If shepherds are paid the value of
the wool, but not the value of the mutton, then shepherds will not be paid enough, and
they will raise too few sheep. Mutton and wool are joint products of rearing sheep.
Efficient incentives require that shepherds receive the sale value of their product
(sheep), which is the sum of the sale value of mutton and wool.

Similarly, commercial applications and pioneering inventions are joint products of
fundamental research. Commercial applications require pioneering inventions, and pio-
neering inventions require fundamental research. A joint product will be undersupplied
if the supplier’s compensation equals the commercial value of only one of the joint prod-
ucts. Ideally, the fundamental research and commercial development would be joined
together in a single firm. If the activities are joined under a single producer, then the pro-
ducer will receive the sum of the value of the fundamental research and commercial ap-
plication, just like paying the shepherd the sum of the value of the mutton and wool.

Even if one firm conducted fundamental research and another firm developed com-
mercial applications, the incentive problem could be solved if transaction costs were
zero. If transaction costs were zero, then the Coase Theorem would apply: breadth of
patent does not matter to economic efficiency so long as inventors can bargain with
each other costlessly and make efficient contracts.

Problems arise under the realistic assumption that transaction costs impede bar-
gaining between suppliers of fundamental research and commercial development. Two
legal remedies are available: lubricate bargaining (Normative Coase Theorem) or allo-
cate rights to the party who values them the most (Normative Hobbes Theorem).
Instead of pursuing these two remedies, U.S. law has been perverse in both respects.

Bargaining among inventors sometimes leads to joint research ventures, in which
competing manufacturers share an R&D facility and compete with each other in pro-
duction and sales. In America, antitrust laws have inhibited joint ventures for research
and development. Thus, the application of antitrust law to R&D obstructed a solution
to the problem of the joint production of inventions. Fortunately, American officials
have recognized this failure in policy and taken steps to correct it.

122 C H A P T E R 5 Topics in the Economics of Property Law

When separate producers make joint inventions, officials face a difficult problem
in determining the breadth of the patents. If the pioneering invention has little stand-
alone value, then some of the improvement’s value must be paid to the pioneer in order
to provide an adequate incentive for pioneering inventions. On the other hand, if the pi-
oneering invention has large stand-alone value, then its inventor often will be rewarded
adequately already, even if he or she receives no share of the value of the improvement.
Thus, patent protection for pioneering inventions should be broader for those with little
stand-alone value, and the patent protection for pioneering inventions should be
narrower for those with large stand-alone value. This is just the opposite of the result
sometimes reached by U.S. courts.7

QUESTION 5.1: When the patent expired on a drug named “Librium” (a
sedative that was the forerunner of Valium), its price dropped from $15 to
$1.10.8 Explain why this drop in price occurred. Relate your explanation to
the problem of efficient incentives for creating and transmitting an idea.

QUESTION 5.2: Recall our example of an investment of $100,000 in research
that yields a pioneering invention that has no commercial value, and a subse-
quent investment of $50,000 in development that yields an improvement that
has commercial value of $1 million. Assume that Firm A is uniquely situated to
do the pioneering research, and Firm B is uniquely situated to develop the appli-
cation. Predict the difference in investment resulting from a broad patent law
and a narrow patent law. In making your prediction, distinguish between a situa-
tion in which transaction costs prevent Firm A and Firm B from bargaining with
each other and a situation in which transaction costs of bargaining are zero.

QUESTION 5.3: When inventions take the form of discovery and applica-
tion, the authorities may issue a “dominant patent” to the pioneering discov-
ery and a “subservient patent” to the improvement. The subservient invention
cannot be manufactured legally without the agreement of the holders of the
dominant patent and the subservient patent. Thus, the two parties are com-
pelled to bargain, each having veto power, and agree on the division of future
profits before manufacturing the improvement. Absent such an agreement,
only the pioneering invention can be manufactured. Answer Question 5.2 un-
der the assumption that, instead of prescribing broad or narrow patents, the
law grants a dominant patent and a subservient patent.

7 The technical name for the legal doctrine giving perverse results is the “doctrine of equivalents.” Applying
this doctrine, courts may find that a pioneering invention with little stand-alone value is not equivalent to
an application of it, so the patent for the former does not extend to the latter. In contrast, the courts may
find that a pioneering invention with stand-alone value is equivalent to an application of it, so the patent for
the former extends to the latter.

8 “‘When Librium, Hoffmann-LaRoche’s forerunner to Valium, came off patent, prices dropped from
$15 to $1,’ said William Haddad, president of the Generic Pharmaceutical Industry Association.”
See “The Shift to Generic Drugs,” New York Times, July 23, 1984, p. 19.

I. What Can Be Privately Owned? 123

1b. Duration As noted, the rights to a patent last for a fixed time period. What is
the optimal patent life? We provide an economic framework for answering this question.
Because patents may create a temporary monopoly that rewards the inventor and over-
charges buyers, the optimal life of a patent strikes the best balance between encouraging
creativity and discouraging dissemination. As the duration of patents increases, society
enjoys more benefits from more innovation. However, the rate at which these benefits
increase presumably decreases. Consequently, the marginal benefit from more innova-
tion decreases as the duration of patents increases. As the duration of patents increases,
society suffers more costs from less dissemination. Society responds to long patents by
searching for substitutes for patented goods. The longer a society searches, the more
substitutes it finds. As with benefits, the rate at which the social costs of patents in-
creases presumably decreases with duration. Consequently, the marginal cost from less
dissemination presumably decreases as the duration of patents increases.

Marginalist reasoning describes the optimal patent life in abstract terms. But what
particular life is optimal? Ideally, there would be a different patent life for each inven-
tion, depending on its individual characteristics.

Such a scheme of individualized patent terms is impractical, but practical alterna-
tives exist to granting a 20-year patent for every invention (the current international de-
fault patent term). Germany, for example, has established a two-tiered patent system.
Major inventions in Germany receive full-term patents, while minor inventions and im-
provements receive petty patents for a term of 3 years. In addition, Germany requires
patent-holders to pay an annual fee to continue the patent. The annual fee is relatively
modest for the first several years of a patent’s life, but thereafter escalates at regular in-
tervals until the patent period is exhausted. Consequently, fewer than 5 percent of
German patents remain in force for their entire term, the average patent life being
a little less than 8 years. This fact is not surprising when you consider that, given an
interest rate of 10 percent, a promise to pay $1 in 8 years is worth less than $.50 today,
and a promise to pay $1 in 20 years is worth less than $.20 today.

Would economic efficiency increase by changing the U.S. system to resemble the
German system? Perhaps. A convincing answer, however, requires much statistical re-
search to provide evidence about broad averages, and that research remains to be done.

1c. Too Much Patent Despite absence of statistical research, evidence exists that
patent law has extended too far and threatens to choke creativity in some areas.
Pharmaceutical research provides an example of such a problem that legislation cured.
To develop a new drug, companies often have to use an existing drug. Fearing competi-
tion, the owners of patents on drugs are reluctant to license their use in research to com-
petitors. This is a case where patent law suppresses the innovation that is the purpose of
it. The Drug Price Competition and Patent Term Restoration Act (1984) (amending the
Food, Drug, and Cosmetic Act, and known as the Hatch-Waxman Act) addressed part of
the problem by allowing the free use of patented compounds in research to develop a
generic alternative. In Merck KGaA v. Integra Lifesciences I, Ltd., 545 U.S. 193 (2005),
the Supreme Court extended this law to research aimed at developing entirely new drugs.

Another example of overextended patent law concerns business methods. In the
past, no one thought that a business method could be patented. However, creative

Optimal Patent Life: Orphan Drugs

We have already remarked on the fact that there is one patent term—20 years. The analysis
of this section has implied that this is not optimal; clearly the social costs and benefits of in-
ventions and innovations differ, sometimes markedly. Ideally, the patent system would recog-
nize these variations by granting different patent terms depending on the net social benefit
of each invention. But the administrative costs of making an invention-by-invention determi-
nation of optimal patent life—or even of putting inventions into classes with different patent
terms—are probably prohibitively high. There are, no doubt, social costs—perhaps, significant
social costs—that follow. For instance, there may be a valuable invention that is extremely
costly to develop but that simply could not generate enough revenues if sold at a reasonable
cost within the 20-year patent term to justify development.

The United States Congress has recognized several important examples of such in-
ventions. One is the Hatch-Waxman Act (Drug Price Competition and Patent Restoration
Act) of 1984. That Act added up to five years of patent life for pharmaceuticals to make
up for time lost in the pre-approval testing of new drugs required by the Food and Drug
Administration (FDA). The Act also eliminated duplicative safety and effectiveness testing
for generic drugs (those that share the chemical composition of drugs that are coming off
patent).

Congress went even further in the Orphan Drug Act of 1983 and its later amendments.
Congress addressed that Act at an instance of the problem we mentioned above—a valuable
invention that might not be developed because the standard patent life was not long enough
to justify the development costs. An “orphan drug” is one for treatment of “any disease or
condition which occurs so infrequently in the United States that there is no reasonable expec-
tation that the cost of developing or marketing the drug will be recovered by sales.” A later
amendment further defined such diseases or conditions as those affecting fewer than
200,000 people in the United States. The Act gives developers of orphan drugs tax credits for
the costs of clinical studies and other subsidies for development costs. In addition, developers
of orphan drugs are given a period of seven-year exclusivity, which may be revoked if the de-
veloper fails to provide the patient population with the drug or abandons the drug.9 Finally,
the FDA greatly accelerates the approval process for orphan drugs, sometimes taking only
eight months for approval.

124 C H A P T E R 5 Topics in the Economics of Property Law

9 This term of exclusivity may strike some readers as odd. Aren’t all patents grants of exclusivity? Yes,
but there is a very important qualification. A normal patent gives the holder exclusive rights to that in-
vention or innovation. But others are free to develop distinct but different inventions that substitute for
(but do not infringe upon) existing patents. (See our brief discussion of the “doctrine of equivalents” in
this section.) So, you may have developed and patented a pharmaceutical that lowers bad blood choles-
terol. But others can develop other chemicals directed at the same end, so long as they are not close
copies of your drug. (Consider that your ownership of a piece of real property gives you exclusive rights
to that property but not to similarly situated pieces of property.) The distinction in the Orphan Drug Act
is that once one has developed a pharmaceutical that meets the criteria for being designated an orphan
drug, no one else can develop even a different drug addressed to the same condition or disease for
seven years (at least under the original formulation of the Act).

lawyers induced the U.S. Patent Office to issue patents on some business methods. The
most famous example is Amazon’s patent on “one-click” Internet orders. Most schol-
ars believe that innovators who create new business methods should not be able to
patent them.

QUESTION 5.4: One possible pitfall of the renewal-fee system for determina-
tion of optimal patent life is that, ideally, we want the patent-holder to compare
the renewal fee with the social benefit of continuing the patent for another year,
not just the private benefit. Can you suggest how, in setting the annual renewal
fee, we might induce patent-holders to make the appropriate social calculation?

QUESTION 5.5: A third means of reducing the social costs of granting a
patent life that is too long is a policy of compulsory licensing. This policy,
which forms part of the patent systems of most Western European countries,
allows frustrated licensees to ask courts to compel patentees to license to them
if they can show that patent-holders have failed to use their patents in the do-
mestic market within a specified time period, have failed to license when that
is essential to bringing a complementary invention into use, or have abused
their positions by, for example, excessively restricting the supply of their
inventions. If the court is persuaded by the prospective licensee to compel
licensing, then it also determines a reasonable royalty. Give an economic
evaluation of the policy of compulsory licensing.

I. What Can Be Privately Owned? 125

10 See Frank Lichtenberg & Joel Waldfogel, “Does Misery Love Company? Evidence from Pharmaceutical
Markets Before and After the Orphan Drug Act,” NBER Working Paper No. 9750 (2007).

The Act apparently had the desired effect. In the 20 years before 1983, the FDA had
approved only 10 orphan drugs. But in 1984 alone it approved 24. During the Act’s first
15 years, the number of orphan drugs increased fivefold, while the number of non-orphan
drugs increased by twofold.10

This record of success notwithstanding, there are some concerns with the Orphan
Drug Act. One has to do with the exclusivity period. That seven-year period, for example,
encourages initial development but discourages development of competing but chemically
different drugs. Congress found this to be undesirable, so in 1993 they passed amendments
to the Act that allowed patenting of second and third orphan drugs directed at the same
disease or condition as the original orphan drug so long as those second and third drugs
were clinically superior in defined ways. There also have been some additional concerns
with the status of orphan drugs. Suppose, for example, that the patient population turns
out to expand beyond the 200,000 threshold or that the orphan drug turns out to be effec-
tive in treating other, non-orphaned conditions or diseases or that the orphan drug turns
out to be extremely profitable. Should the orphan status be revoked in these instances?
Congress has addressed these issues but has not yet reached agreement on what to do
about them.

126 C H A P T E R 5 Topics in the Economics of Property Law

1d. Conclusion on Patents As explained, the original economics of informa-
tion concluded that an unregulated private market will undersupply information.
Remedies to the problem include public supply or subsidies for scientific research,
charitable donations, and intellectual property rights. This view still dominates most
policy discussions. However, special situations can occur in which no regulation or
subsidies results in too much information or just the right amount.11

To see why, consider the invention of a superior means of forecasting the weather.
The original theory argued that the inventor cannot appropriate the value of the inven-
tion because people who buy her forecasts can resell them to others. However, there are
alternative means for inventors to earn profits. The inventor of the weather forecast, for
example, can profit by speculating on agricultural prices. To see how, let’s suppose that
the inventor forecasts a rainy autumn that will reduce harvests and cause the price of
corn to rise. She can keep this information secret and buy corn in the summer for deliv-
ery in the autumn. Presumably, if everyone else anticipates normal fall weather, the
price of corn in the summer for autumn delivery will be low—too low, the inventor of
the weather forecasting method knows. When the harvest arrives in the fall, farmers
will fulfill their contracts by delivering corn to the inventor at the low, summer price.
Subsequently, the inventor can resell the corn on the spot at the high price caused by a
rainy autumn. Thus, Aristotle asserts that Thales of Miletus used philosophy to predict
the weather and made a fortune on what amounted to olive press call options.12

In general, the producers of information can obtain profits from speculative in-
vestments. In Silicon Valley, an inventor often participates in founding a firm and
owns a lot of its stock. The inventor presumably knows more than the public about the
firm’s future performance. The invention may give the firm a competitive advantage
in several respects beyond its immediate application. For example, the firm may learn
many things about applying and marketing the invention in various fields ahead of its
competitors. Also, the firm may establish its brand name over products associated
with the invention. Once the market learns the firm’s true value, the inventor’s stock
will appreciate.

Following this line of thought, some scholars have argued that some markets pro-
duce too much investment in information. For example, consider the stock market as a
whole. An investor who finds out sooner than others that one corporation is buying an-
other can make large profits by purchasing the target company’s stock. The gains to so-
ciety from faster price movements in the target company’s stocks are modest compared
to the vast wealth redistributed from uninformed stockholders to informed investors.
This fact is one reason why securities laws in the United States and elsewhere forbid
members of a firm from trading its stock based on information that they have not yet
made public—the prohibition against insider trading.

Investors race to buy a stock whose price will rise before someone else does, which
creates the possibility of excessive trading. Similarly, fishermen race to catch the fish

11 J. Hirshleifer The Private and Social Value of Information and the Reward to Innovative Activity, 61 Am.
Econ. Rev. 561 (1971). See also R. Posner, The Social Costs of Monopoly and Regulations, 83 J. POL. ECON.
807 (1975), and E. Rice & T. Ulen, Rent-Seeking and Welfare Loss, 3 RES. IN LAW & ECON. 53 (1981).

12 Aristotle’s Politics, Book 1, Chapter 11. Thanks to Eric Rasmusen for this example.

I. What Can Be Privately Owned? 127

in the sea before someone else does, which causes tragic over-fishing. Inventors race to
secure patents. Unlike the Olympics, patent law typically (but not always) has no silver
medals—the second-place finisher often gets nothing. Are inventions like fish in the
sea? No. The advantages of growth are so vast that society benefits from the innovation
race, even when it is frenetic. Beating the competition in a patent race has negative ex-
ternalities, but inventions cause much larger positive externalities that the public enjoys
as the innovations disseminate.

Before concluding this section, we want to mention a reason why patent protection
for some inventions is higher than commended by economic efficiency. In addition to
the legal monopoly sometimes given by a patent, some inventions create natural mo-
nopolies. A natural monopoly exists when average costs fall as the scale of production
rises. Given a natural monopoly, the largest firm with the lowest costs can drive out the
competition. For example, spreading research and development costs over larger pro-
duction volumes reduces the average cost of innovation. Thus, the average cost of de-
veloping an operating system for users of personal computers falls as the number of
users increases. In information technologies, industry standards provide an additional
element of natural monopoly. To illustrate, standardizing the key strokes required to
move the cursor in a word processing program lowers the learning cost of word pro-
cessing to everyone. As the standard becomes more dominant, users value it more.
Consequently, any company that can establish exclusive rights over an industry stan-
dard can enjoy an element of natural monopoly and exploit this power in licensing the
right to use the standard.

If an invention is the basis of a natural monopoly, then the inventor can obtain mo-
nopoly profits even without a patent. To do so, the inventor must use his lead-in time to
expand his business and innovate faster than the competition. By growing and innovat-
ing faster than the competition, the leader enjoys increasing returns to scale, which con-
vey monopoly profits. To illustrate, assume that a computer software product begins
with a fundamental discovery and then undergoes constant improvement through inno-
vation. To finance constant improvement, a company needs a significant level of sales.
The original inventor may achieve the critical sales level before anyone else and then
price the product low enough to preclude entry by other firms. The price that precludes
entry into the market by competitors (the so-called “entry-limiting price”) can still
yield supra-competitive profits to the producer.

Natural monopoly is such a common feature of networks that its occurrence in
networks has a special name—network effects. The economic analysis of network ef-
fects began with railways in the nineteenth century. The most efficient organization of
a railway usually requires lines to radiate from a central terminal. The central terminal
is the “hub” and the radiating lines are the “spokes.” (This same language is now ap-
plied to airlines.) The owner of the central terminal can favor connections to its own
railway lines and disfavor connections to competing railway lines. This network effect
in railways confers a large advantage on the owner of the central terminal for a region.
Similarly, information-based industries often rely on connections analogous to the
central railway terminal. For example, all the software on a personal computer must
use its operating system. An exclusive owner of the operating system for personal
computers can favor the use of its own software and disfavor the use of rival software.

128 C H A P T E R 5 Topics in the Economics of Property Law

Such a pattern of abuse was the central allegation of the U.S. Justice Department in its
recent antitrust suit against Microsoft. Owning a computer operating system has been
analogized to having a patent on use of the English language.

QUESTION 5.6: Suppose that the inventor of a weather-forecasting tech-
nique determines that the weather during the growing season will be perfect,
causing a bumper harvest. Explain how the inventor could use this informa-
tion to make profitable investments.

QUESTION 5.7: The directors of a corporation are often the first people to
know about facts that affect its stock price. American law forbids directors and
other “insiders” from using “inside information” to speculate on the value of the
company’s stocks. Use the theory of first appropriation and the economics of in-
formation to make arguments for and against the efficiency of this prohibition.

Web Note 5.3

See our website for additional law-and-economics literature on patent issues.

Patent (and Other) Prizes

The economic argument for patents asserts that giving the developer of a new, useful, and
nonobvious invention or innovation an exclusive right encourages investment in and dissemi-
nation of new methods, machines, and practices. But there has always been skepticism about
the necessity of the patent system. Critics have long argued that the shortcomings of that
system—particularly the high prices and restricted output of monopoly—are not worth the
alleged benefits.13 Indeed, because of their deep concerns about the ill effects of the IP
system, several European countries, including Sweden and the Netherlands, suspended their
intellectual property systems for several decades in the mid- and late nineteenth century.

But if there is no patent system, how can society encourage investment in invention and
dissemination? One possible method is through the award of prizes. These can be monetary
rewards for designated accomplishments or for general innovations, and they can be offered
by either public or private parties or both simultaneously. Perhaps the best example of a pub-
lic reward designed to induce a particular invention is the English government’s search for an
accurate method of measuring longitude.14 Using sightings of the sun, ships could relatively
easily measure latitude, their distance north or south of the equator. But with regard to longi-
tude they were—well, at sea. The results of not knowing where one was could be, and some-
times were, disastrous. In response to a famous ship disaster, the English Parliament decided
to do something. In 1714 they offered a reward of £20,000 to the first person who could

14 See DAVA SOBEL, LONGITUDE (1997).

13 See for example, Michelle Boldrin & David Levine, The Case Against Intellectual Property, 92
AM. ECON. REV. 209 (2002). See also the authors’ Against Intellectual Property (2008).

I. What Can Be Privately Owned? 129

accurately measure longitude at sea. To evaluate the submissions, Parliament appointed a
Board of Longitude, with Sir Isaac Newton as its Prime Commissioner, and they required a
testing voyage to the West Indies with criteria for success.

A carpenter and clockmaker in Yorkshire, John Harrison, thought that the key to meas-
uring longitude was an extremely accurate clock. (Most of the other inventors who pursued
the prize thought the key lay in accurate sightings of celestial objects.) Harrison’s insight
was that the Earth turned through 360 degrees, a complete rotation, in the course of
24 hours. As a result, the Earth turns through 15 degrees each hour of each day. A traveler
who departed from London to Moscow could set his watch for London time and compare
it to the time when he reached Moscow. He would find that his watch said 9:00 am when
it was noon in Moscow, which would enable him to deduce that Moscow is east of London
by 45 degrees of longitude. If it were possible to measure the time difference between a
ship at sea and at a fixed point on the Earth’s surface (such as at London), then one could
tell how far around the Earth one had gone. For this method of measurement to work
would require having an extremely accurate clock. And that was the task that Harrison set
himself.

In the eighteenth century, ships’ clocks were inaccurate because the motion of the ship
disrupted the clock’s mechanism. In 1759, Harrison finally developed an extremely accurate
ship’s clock, which he called H-4. In 1764 the Board of Longitude ordered H-4 to be tested on
a ship traveling from Portsmouth to Barbados, and Harrison’s son, William, went to Barbados
to oversee the test. The clock performed marvelously, but rivals blocked Harrison from receiv-
ing the prize until his son made a dramatic and successful appeal to King George III. Harrison
finally received his reward 43 years after he had begun his quest.

England was not put off by this experience. Parliament later offered a reward for the first
successful vaccine against smallpox.

There are many—indeed, an increasing number of—private prizes designed to elicit
particular inventive activity. The Ansari X Prize, created in 1996, famously offered $10 mil-
lion to the first private team that could finance, build, and launch a spaceship capable of
carrying three people to a height of 100 km (62.5 miles) above the Earth, return safely to
Earth, and then repeat the trip with the same ship within 2 weeks. A group headed by Burt
Rutan and Paul Allen, the cofounder of Microsoft, won the prize in October, 2005. Recently,
the Progressive Insurance Company announced a $5 million prize for the first team or indi-
vidual to develop a car with an internal combustion engine capable of getting 100 miles per
gallon of gasoline.

Some have suggested that the successes of rewards for particular achievements can be
extended to general inventions. Steve Shavell and Tanguy van Ypersele have argued that a
system of general governmental rewards for the developing of new, useful, and nonobvious
inventions is superior to the current system of awarding patent rights.15 Are the social costs
and benefits of a reward system clearly superior to those of the current patent system? Could
one argue that public and private rewards for inventive activity complement the patent sys-
tem so that the two systems should operate together?

15 See Steven Shavell & Tanguy van Ypersele, Reward Versus Intellectual Property Rights, 44 J. LAW &
ECON. 525 (2001). See also Michael Abramowicz, Perfecting Patent Prizes, 56 VAND. L. REV. 115 (2003).

130 C H A P T E R 5 Topics in the Economics of Property Law

2. Copyright In our analysis of patents, we applied the economics of informa-
tion to answer the two fundamental questions about breadth and duration. This same
framework applies to other topics in intellectual property, notably copyright and
trademark, which we discuss briefly. Copyright grants writers, composers, and other
artists property rights in their creations on demonstration that their works are original
expressions.16 Unlike the patent system, the U.S. copyright system does not require
creators to register their works in order to receive the protection of copyright. But
very much like the patent law, copyright protection is limited in breadth and duration.

The breadth of a copyright concerns the uses to which copyrighted material can be
put without authorization. A broad copyright forbids any unauthorized use, whereas a
narrow copyright permits some unauthorized uses. For example, books are quoted in
reviews and satires, or photocopied or distributed electronically for educational pur-
poses. The law handles these uses through so-called fair-use exceptions. For example,
in Sony Corporation of America v. Universal City Studios, Inc., 464 U.S. 417 (1984),
the Betamax case, the U.S. Supreme Court held that recording over-the-air copyrighted
television programs on a videocassette recorder is fair use when done for “time-shifting”
purposes, but not necessarily for purposes of “archiving.” A vague line, frequently liti-
gated, divides fair and unfair unauthorized copying.

Since its eighteenth century beginning, the United States has lengthened the duration
of a copyright until it now stands as the creator’s life plus 70 years.17 The optimal duration
of a copyright involves a different problem from patents—specifically, tracing costs.18

Before producing her own copyrightable material, a creator may want to check to see if
her ideas for a novel, say, are original. The costs of searching among all novels to make
sure her idea does not, unintentionally, infringe on someone else’s copyright can be exten-
sive. To limit these costs, creators are given limited duration and relatively narrow breadth
for their creations. However, the increasing ease of copying and the spread of literacy in-
crease the ability of others to avoid paying the copyright-holder a royalty. So, the length-
ening of copyright protection allows creators a longer time to recoup their just royalties.

In some areas, copyright and patent law have extended too far and threaten to
choke creativity. To appreciate the problem, imagine that someone obtains copyright to
the English language. No one would be able to say anything without paying a license
fee. This copyright would suppress language creativity. Similarly, many computer
experts believe that fundamental computer languages should remain in the public
domain where people can freely modify, adapt, improve, and use them. In this way the
Linux operating system has developed into a powerful programming tool. As we move

16 As Lord Macaulay put it, copyright is “a tax on readers for the purpose of giving a bounty to writers.”
THOMAS B. MACAULAY, SPEECHES ON COPYRIGHT 25 (C. Gaston ed. 1914).

17 In October, 1998, Congress passed the Sonny Bono Copyright Term Extension Act, which lengthens copy-
right protection for works created on or after January 1, 1978, to the life of the author plus 70 years, and
extends existing copyrights “created for hire and owned by corporations” to 95 years. Before the change,
the 1976 Copyright Act had given protection for the author’s life plus 50 years. Whatever other reasons
there may be for the Copyright Term Extension Act, one justification is that it brings U.S. practice into
conformity with Western European practice.

18 William Landes & Richard A. Posner, An Economic Analysis of Copyright Law, 18 J. LEGAL STUD. 325
(1989). See also Wendy Gordon, On Owning Information: Intellectual Property and the Restitutionary
Impulse, 78 VA. L. REV. 149 (1992).

I. What Can Be Privately Owned? 131

away from operating systems to more applied programs, however, private owners con-
trol the most successful programs. Examples are Microsoft Word and Google. We could
analogize operating systems to the English language and applied programs to novels.
These facts suggest a natural boundary between open source and proprietary software.
Computer programs hotly contest the proper location of this boundary. Their rhetoric
can sometimes sound like a religious war of the seventeenth century or the bitter dis-
pute between socialists and capitalists in the twentieth century.

The historical legacy of copyright law often hinders and obstructs communications
among scholars and slows scientific development. Before the Internet, scholars com-
municated mostly on paper when they did not talk to each other. Publishing an aca-
demic journal on paper is costly, so the publisher has to restrict access by charging high
subscription fees. With the Internet, the cost of disseminating journal articles plum-
meted; yet, the same academic journals with their high subscription fees dominate
many academic fields. To change the situation, some scholars now refuse to transfer
copyright over their articles to the publishers of journals with high subscription fees, or
they reserve Internet dissemination rights for themselves. An initiative called the
“Creative Commons” attempts to create a new, private copyright standard that guaran-
tees for authors the right of cheap dissemination of their scholarship on the Internet.19

What is the future of copyright in the digital age? According to one vision of the fu-
ture, most users of digital information will download it from a few large sellers who im-
pose uniform charges. In this system, obtaining information resembles putting money in
a jukebox to hear a song. According to the “celestial jukebox” model (see Paul
Goldstein’s book, cited at the end of this chapter), every user of digital information will
resemble contemporary U.S. radio stations that must pay standardized royalties to a cen-
tral clearinghouse whenever they broadcast a song. If the celestial jukebox succeeds,
copyright will become the dominant law of the digital age. According to an alternative
vision, however, copyright law will die because technology will make law unnecessary.
In the model of “digital libertarianism,” technical protection through cheap encrypting
will be more efficient than legal protection of intellectual property. Cheap encrypting will
allegedly enable producers of digital information to control who uses it without much
need for law. Are new laws the answer to new machines, or are new machines the answer
to new machines? If you think you know whether the future will bring the celestial juke-
box or digital libertarianism, then you should immediately go buy technology stocks.

Web Note 5.4

Our website considers much more on the economics of copyrights, such as the
recent legal controversy regarding downloading copyrightable material from
the Internet, constitutional objections to the copyright extensions of the late
1990s, further proposals for copyright reform, and a recent proposal by Judge
Richard Posner and Professor William Landes for an indefinitely renewable
copyright.

19 The Creative Commons, a project of Professor Lawrence Lessig of the Stanford Law School, allows
authors, composers, and other creators to choose among a variety of protections for their expressions.
See www.creativecommons.org.

132 C H A P T E R 5 Topics in the Economics of Property Law

3. Trademark Many modern businesses and service organizations invest vast sums
of money to establish easily recognizable symbols for their products. For example,
children in many countries recognize the golden arches signaling the location of a
McDonald’s franchise. Such symbols are trademarks or servicemarks. The common
law and statutes protected trademarks from as early as the 13th century in England.
Proprietary rights in a trademark can be established through actual use in the market-
place, or through registration with the trademarks office. Modern trademark law in the
United States stems from the Federal Trademark Act of 1946, commonly called the
Lanham Act. The act provides a method for obtaining federal registration for trade-
marks or servicemarks.20 As in the case of patents, the successful applicant must estab-
lish that the mark passes certain criteria, the most important of which is distinctiveness.
Registration with the U.S. Trademark Office entitles the holder to certain protections
and rights, among which is the privilege of placing beside one’s trademark a sign, ®,
that indicates a registered trademark.21 The owner of a trademark can sue for infringe-
ment to prevent unauthorized use .

Trademarks help to solve the problem of consumer ignorance about the quality of
a product. When quality is opaque, the consumer can use the trademark as a signal of
quality. Furthermore, trademarks reduce the cost to consumers of searching for a prod-
uct with specific qualities. The principal economic justifications for granting property
rights to trademarks are that they lower consumer search costs and create an incentive
for producers to supply goods of high quality.

Marketing in Eastern Europe before the fall of communism in 1989 shows what can
happen without trademarks. State stores sold unbranded goods with generic
labels—“bread,” “shirt,” “oil,” or “pen.” A consumer would find one or two unbranded
pens on a store’s shelf, so he or she could not tell who designed or manufactured them. A
purchase was a random draw from the universe of state factories. Because factories could
not acquire reputations with consumers, they could not compete to improve quality. In
contrast, trademark law enables a company to build up a reputation for high quality
and credible advertising, so it can compete with other companies on these dimensions.

The general problem of credibility is central to information economics. Buyers of
information generally cannot determine its value until they have it. To illustrate, a
banker recently received a letter that read, “If you pay me $1 million, I’ll tell you how
your bank can make $2 million.” The only way to make this claim credible is by pro-
viding the information to the bank. After the bank has the information, however, it has
no reason to pay for it. Similarly, to assess the value of innovative software, a large
buyer like Microsoft must understand how it works. After learning how the product
works, however, Microsoft may produce its own version of the product rather than pay-
ing royalties to the small company.

Notice that the economic justification for trademarks is different from those for
patents and copyrights. Unlike patents and copyrights, the economics of trademarks

20 Note, however, that one does not have to register a mark in order to receive a property right in that mark.
21 Some producers place the symbol TM or SM (for servicemark) on their products, but those symbols have

no legal status.

I. What Can Be Privately Owned? 133

23 The Bayer Company of Germany had discovered acetylsalicylic acid in the late 1890s. The U.S. govern-
ment seized the trademark “Aspirin” during World War I and sold the right to use that tradename to the
Sterling Drug Company in 1918. Interestingly, Bayer purchased Sterling in 1994.

does not concern innovation, temporary monopoly, or constrained dissemination.
Consequently, we cannot make the same economic argument for limiting the duration
of the property rights in trademarks as we did in the case of patents and copyrights.
Limits on the duration of patents and copyrights were justified as attempts to minimize
the social costs of monopoly and tracing. However, trademarks encourage competition
and do not impose tracing costs.22 Perhaps this is why trademarks can last forever, un-
til abandoned. In this respect, trademarks are like property rights in land and unlike
other forms of intellectual property.

The question of breadth in trademarks has an interesting twist. Nothing is more
settled in the law of trademarks than the proposition that generic product names can-
not be trademarks. For example, no producer of cameras may register the word
“camera” as a trademark. To allow such a trademark would enable its owner to sue
every camera manufacturer that advertised its product by use of the word “camera.”
If generic product names could be trademarks, then the law of trademarks would
create monopoly power, rather than facilitating competition. Sometimes, however, a
competitive product succeeds so far that its trademark becomes a generic name. For
instance, people today speak of “xeroxing” when they mean “photocopying,” or they
speak of “Scotch tape” when they mean cellophane tape, or they speak of a
“Hoover” when they mean a vacuum cleaner. When this situation arises, the trade-
mark owner must protect the trademark by suing rivals who use the generic name to
describe their products. Otherwise, the producer loses its property right in the
generic name.

This sort of thing happened to the Sterling Drug Company in 1921. In that year
a U.S. federal district court determined that Sterling’s trademarked name for
acetylsalicylic acid, “Aspirin,” had become the common word for any brand of that
drug, not just Sterling’s. After this ruling, all producers of acetylsalicylic acid
could use the term “aspirin” to describe their product. Bayer has managed to pre-
vent this erosion of its trade name Aspirin in Mexico and Canada, where no com-
pany but Bayer may describe its acetylsalicylic acid as “aspirin.”23 To learn how
manufacturers of very successful products protect their trademarks, read the box
on “Coke” on page 134.

Besides quality, trademarks also signal prestige. In some east Asian markets a con-
sumer can choose an unbranded watch and then choose the brand name to put on it.
Thus, a consumer can get the prestige of a watch that proclaims itself to be a “Rolex”
without paying the cost. These “knockoffs,” which violate trademark laws, reward the
consumer and cheat the manufacturer of the authentic good. Unfortunately, standard
economic tools were not designed for prestige, and they do not do a good job of meas-
uring the costs and benefits of knockoffs.

22 See, for general information, William Landes & Richard A. Posner, Trademark Law: An Economic
Perspective, 30 J. LAW & ECON. 265 (1987).

134 C H A P T E R 5 Topics in the Economics of Property Law

QUESTION 5.8: The duration of copyright increased under U.S. law in sev-
eral steps since the eighteenth century until it reached the life of the author plus
70 years. Suppose that a writer completes a novel at age 40. If the writer lives
to be 75, then the copyright will last for 105 years. At an interest rate of
10 percent, the present value of $1 paid after 105 years equals much less than
5 cents. What does this fact suggest about whether the efficient duration of
copyright is longer or shorter than currently provided by law?

QUESTION 5.9: In 1939 the composer Igor Stravinsky received $6000 from
Walt Disney for the right to use “The Rite of Spring” in the animated film
“Fantasia,” featuring Mickey Mouse. Should Disney own the exclusive right
to release the film in videocassette, which generated $360 million in revenues
in the first two years after its release in 1996, or are Stravinsky’s assignees en-
titled to some of the money?24

24 James Zinea, “A Discordant Ruling,” Forbes, October 5, 1998, p. 66.

“Coke” Is It!

One of the best-known trademarks in the world is the word “Coke” to describe the Coca-
Cola Company’s cola soft drink. Precisely because it is so well known, there is the danger to
the Coca-Cola Company that consumers might use the designation “Coke” to refer to any
cola soft drink and not just the one the Coca-Cola Company produces. If that should happen,
then “Coke” will have become a generic product name that any producer may use. The
Coca-Cola trade research department, which has an annual budget of redundant millions of
dollars and employs a team of investigators whose job it is to roam the United States asking
at restaurants and soda fountains for “Coke” and “Coca-Cola.” The investigators then send
samples of what they are served to the corporate headquarters in Atlanta for chemical analy-
sis. If the company determines that a restaurateur has served them something other than
Coca-Cola, then that business is advised of its wrongdoing.

Since 1945, Coca-Cola has sued approximately 40–60 retailers per year. Retailers claim
that what lies behind the company’s vigorous campaign is not a fear of trademark infringe-
ment but an insidious and anticompetitive attempt to browbeat retailers into dealing only
with the Coca-Cola Company. They note that it is frequently too costly for them—as on a
busy night—to tell each customer who asks for a rum and Coke that they are really going to
get a rum and Pepsi. Rather than face a lawsuit for trademark infringement, many of the re-
tailers simply signed up with Coca-Cola as their exclusive supplier, saying that to do so was
less costly to them. The retailers point to the fact that Coke has an 80 percent market share
in the fountain-soda market but a much smaller share of the supermarket sales as evidence
that the trade research department’s work is part of an anticompetitive marketing operation.

(See “Mixing with Coke Over Trademarks Is Always a Fizzle: Coca-Cola Adds a Little Life in Court to Those Failing
to Serve the Real Thing,” Wall Street Journal, March 9, 1978, p. 1, col. 4.)

I. What Can Be Privately Owned? 135

QUESTION 5.10: No one may use a patent without the patent-holder’s permis-
sion. But in a limited set of circumstances, others may use copyrighted material
without the copyright-holder’s permission. These circumstances—called the “fair
use” exception—allow, for example, reviewers to quote from copyrighted mate-
rial without permission, teachers to photocopy or distribute electronically and as-
sign limited portions of copyrighted material to their classes, and musical groups
to include or “sample” copyrighted music in their own compositions.

Use economic theory to explain why it may be efficient to allow the fair
use exception.

QUESTION 5.11: Why is it efficient to limit the duration of patents and
copyrights, whereas real property rights endure almost forever (with an im-
portant exception to be noted later in this chapter)?

QUESTION 5.12: Trademark law does not allow a holder to sell a trademark
independent of the good to which it is attached. Thus, Coca-Cola cannot sell its
use of the trademark “Coke” to another producer of cola syrup; that mark may
be sold only with the syrup produced by or under the supervision of the Coca-
Cola Company. Can you provide an economic rationale for this restriction?

Web Note 5.5

What are the appropriate remedies for unlawful use of a patent, copyright, or a
trademark? See our website for a discussion of the economics of those issues.

Web Note 5.6

This section has only skimmed the surface of the remarkable developments in
intellectual property of the last 10 years. See our website for more on the is-
sues of the law, such as private ownership versus “open source” software, how
the fashion industry uses IP, and how magicians, cooks, and comedians pro-
tect their intellectual property.

C. Organizations as Property
Families, clubs, churches, cooperatives, trusts, charities, and the state are organiza-

tions that own property, such as land, buildings, and machinery. An organization, however,
is not the same as the property that it owns. For some kinds of organizations, the members
can buy and sell assets, but no one can buy or sell the organization. To illustrate, no one
owns a family, club, church, cooperative, trust, charity, or state. In contrast, corporations
have owners who buy and sell, not just the corporation’s assets, but also the corporation it-
self. In brief, many organizations own property and some organizations are property.

Owned and unowned organizations perform different roles in society. Unowned
organizations play the central role in social life, religion, and government, whereas

136 C H A P T E R 5 Topics in the Economics of Property Law

corporations play the central role in production and economic growth. We will explain
the connection between the difference in ownership and the difference in function.

To begin, consider what an organization is. Organizations generally have a struc-
ture of offices created by laws and contracts, such as Chairman, Treasurer, or
Ombudsman. While some members of organizations have offices, all members have
roles to play. Standardization in the division of labor creates roles like bookkeeper, me-
chanic, or purchasing agent. By supplying a structure of offices and roles, an organiza-
tion coordinates the behavior of its members so that it can pursue goals. When
coordination is tight enough, observers of the organization ascribe goals to it, not just
to its individual members. Thus, we can define an organization as a structure of offices
and roles capable of corporate action.

Organizations adjust their structure to improve performance or change goals.
Owned organizations adjust in response to pressure from markets for organizations. For
example, corporate officers who fail to perform may find their company bought by a
new owner who fires the old managers and replaces them with new managers. In con-
trast, an unowned organization avoids pressure from the market for organizations
because no one can buy or sell it.

We must consider how a market for organizations changes their behavior. According
to the bargain theory of property developed in this book, markets tend to move property
from people who value it less to people who value it more. Thus, the market for organiza-
tions tends to move organizations from owners who value them less to owners who value
them more. Corporations are primarily instruments to make money, so the owners of cor-
porations tend to value them according to their profitability. Consequently, the market for
corporations tends to bring the ownership of each corporation to the people who can
make the most profit from them. Under ideal conditions described in the model of perfect
competition, profitability measures the social value created by a corporation. When real-
ity approximates these conditions, the market for corporations maximizes the nation’s
wealth by transferring ownership to the people who can run corporations most profitably.

Because no one owns a family, club, church, cooperative, trust, charity, or state,
there are no markets to move control of these organizations to the people who can make
the most profit from them. Consequently, the primary purpose of these organizations is
not profits. Instead of being an instrument for wealth, most members regard these or-
ganizations as primarily serving other purposes. If these organizations were owned,
pressure from the market for organizations would divert their purpose to profitability.
Consequently, no one should own an organization whose purpose is not profit, which is
what we observe in fact.

The owner of property enjoys discretionary power over it, including the right to
transform it. When an organization is owned, the owner usually has the power to re-
structure its offices and roles, and change the people who fill them. This owner’s legal
power over an organization often suffices to control it. When an organization is un-
owned, however, no one may control its offices and roles. The alternative to ownership
is often governance. A system of governance involves politics and collective control.
To illustrate the difference, the owner of a small corporation controls it and does with it
as he wishes, whereas the members of a club, church, cooperative, or democratic state
make collective decisions and engage in politics. Ownership is usually best for pursu-
ing wealth, and governance is usually best for pursuing more diffuse goals.

I. What Can Be Privately Owned? 137

We have explained that different organizations have different functions, and
the primary function of corporations is to create wealth by pursuing profits. The
market for corporations helps to keep management focused on this task. Markets
for corporations, however, are often “thin,” by which we mean that there are few
buyers or sellers. To illustrate, economic recession at the turn of the 21st century
and destruction of the World Trade Center by terrorists caused a significant decline
in the number of air travelers. In this environment, many (but not all) airlines are
unprofitable. This situation creates pressure for the owners of unprofitable airlines
to sell them. The potential buyers are few in number, because airlines are very ex-
pensive to buy and running them requires expert knowledge. The market for air-
lines is “thin” in the sense of having few buyers and sellers. The problem of thin
markets is aggravated by antitrust authorities who may prevent one airline from
merging with another. In general, blocking mergers to thicken product markets
thins the market for corporations.

As a market thins, competitive pressures diminish. Specifically, thin markets for
corporations allow their members to pursue goals other than maximizing the com-
pany’s profits. Understanding this fact requires appreciation of the history of corporate
law. Corporations are very old forms of organization. For example, the British govern-
ment financed itself in the past partly by selling exclusive licenses to large corporations
to develop trade in the colonies. As a specific example, the Hudson’s Bay Company
was formed in 1670 and was soon thereafter given control over fur trading and other
businesses in the area amounting to one-third of present-day Canada.

Two important legal innovations distinguish these historic corporations from mod-
ern corporations. First, like the Hudson’s Bay Company, the charters of the historic
companies restricted them by activity and geography. In contrast, modern corporations
can enter almost any form of business in any place. To illustrate, a corporation char-
tered in Indiana can enter almost any kind of business in any other U.S. state.
(Corporations are restricted from entering a few lines of business in the United States
that are reserved for partnerships, notably law and accounting, or require separate in-
corporation, notably commercial banks.) Removing restrictions on activities and geog-
raphy vastly increases competition among corporations.

Second, the owners of the historic corporations were liable for the corporation’s
debt. To illustrate, if the Hudson’s Bay Company had gone bankrupt in the eighteenth
century, then its creditors could obtain repayment by seizing the wealth of its stock-
holders. Given unlimited liability of investors in a company for its debts, people who
invest must carefully monitor and control the company’s policies. In contrast, the own-
ers of modern corporations are not liable for the corporation’s debts. To illustrate, if an
airline goes bankrupt, its creditors can liquidate its assets, but its creditors cannot seize
the homes, cars, or bank accounts of its stockholders. As a result of limited liability,
people who invest in stock run the risk of losing their investment and nothing more.
Limited liability allows people to invest in a company without monitoring or control-
ling the company’s policies so thoroughly.

Limited liability is an aspect of the more general problem of separating the assets
of a company from the assets of its owners and managers. Limited liability prevents the
creditors of the company from reaching the personal assets of the company’s owners.
An equally important body of law prevents the creditors of the owners from reaching

138 C H A P T E R 5 Topics in the Economics of Property Law

the assets of the company. Separating the assets is called “partitioning,” and not sepa-
rating the assets is called “co-mingling.” Modern corporate law partitions the assets of
corporations and their owners, whereas the law historically co-mingled them.

Limited liability has created a situation commonly described as the separation of
ownership from control. This phrase refers to the fact that many stockholders in large
companies sold on public stock exchanges do little monitoring of it and have no con-
trol over it. Sometimes a small number of large investors monitor and control the cor-
poration. Often, however, none of the owners exercises control over the corporation.
Instead, control over the corporation rests with its management. Most investors want to
make money, so they want the managers to maximize profits. The managers, however,
have their own goals to pursue.

A vigorous market for corporations can prevent managers from pursuing goals
other than maximizing the company’s profits. In general, the stock market bids up the
price of a company’s stock until it equals the sum of the company’s expected future
earnings discounted to present value. If managers fail to maximize the company’s prof-
its, then the expected future earnings of the company fall and its stock price declines.
Under these circumstances, an outsider may attempt to buy the company and replace its
management. As this theory predicts, econometric evidence demonstrates that the stock
price of firms rises and remains higher as a consequence of a successful hostile takeover.
So, the new managers must make the acquired firm more profitable. Foreseeing the pos-
sibility of a hostile takeover helps to prevent managers from departing very far from the
goal of maximizing the company’s profits. Conversely, a thin market for corporations
makes hostile takeovers unlikely, so managers can pursue other goals than profits.

In recent years, much scholarship and research on corporations concerns how the
law ameliorates or exacerbates problems created by the separation of ownership from
control. For example, managers employ various contractual devices to reduce the pos-
sibility that someone will buy the company and bring in new managers (for example,
“poison pill,” “golden parachute,” “lock-ups,” and non-voting shares of stock). Also,
managers have succeeded in persuading legislators to enact statutes to reduce the effec-
tiveness of the market for corporate control (notably the Williams Act).

Before beginning a new topic, we want to connect this discussion of organizations
as property to the discussion of contracts in Chapter 8. The problem of the separation
of ownership from control in the modern corporation has a general analytical form.
Owners often placed their assets under the control of someone else. In these circum-
stances, economists describe the owner as the “principal” and the controller as the
“agent.” The principal-agent problem is to write a contract that gives the agent incen-
tives to manage the asset in the best way for the principal. A later chapter uses the prin-
cipal-agent model to develop the theory of contracts.

QUESTION 5.13:

a. Give a concrete example of the difference between ownership and gover-
nance in organizations. In your example, which form of organization has a
higher transaction cost of making decisions?

b. Find a concrete example of a corporation whose managers faced a hostile
take-over bid that succeeded. After the take-over, what happened to the
managers of the acquired firm?

I. What Can Be Privately Owned? 139

25 See R.J. Agnello & L.P. Donnelly, Property Rights and Efficiency in the Oyster Industry, 18 J. LAW &
ECON. 521 (1975). See also G. Power, More About Oysters Than You Wanted to Know, 30 MD. L. REV. 199
(1970).

D. Public and Private Property
Having discussed the ownership of organizations, we return to a discussion of the

ownership of assets like land, buildings, and machinery by organizations. We will use
our theory of property to explain the difference between private and public ownership
of a resource. Private and public externalities differ according to the number of affected
people. Similarly, private and public ownership can be distinguished by the number of
owners. A resource owned by a single individual is private. A corporation owned by a
small group of stockholders (“closely held corporation” or “close corporation”) is a
“private company.” Corporations owned by many shareholders are “public companies.”
Similarly, the state is called the “public sector.” When the state owns a resource, such
as a public park, we sometimes say that the resource belongs to all of the citizens or
that it belongs to no one other than the state.

What difference does the number of owners make? In discussing the Coase
Theorem, we described bargaining among the owners of separate properties, such as
the rancher and the farmer. Bargaining also occurs when several people own the same
property. For example, the partners in a business bargain over the allocation of tasks.
The difference between private and public ownership can be described as a difference
in the structure of bargaining.

Private ownership divides people into small groups. So long as externalities are
private, private owners can advance their interests by cooperating with a small number
of people. Bargaining among small groups of people tends to result in cooperation and
to achieve efficiency. Consequently, the case for private ownership is easy to make
when production and utility functions are separable, or when externalities affect few
people. In these circumstances, public ownership is a costly mistake.

An illustration comes from a study of oyster beds along the Atlantic and Gulf
coasts of the United States.25 At an early stage in their lives, oysters attach themselves
permanently to some subaqueous material, such as rock. This attachment makes it
possible to imagine defining private property rights in oysters for commercial fishing
operators. However, the states along the Atlantic and Gulf coasts that have commer-
cial oyster industries have not settled on a single system of property rights for oysters.
Some states have determined that the subaqueous areas where oysters tend to congre-
gate are to be common property for oyster harvesters; any of them may take oysters
from those areas, and none may exclude another. Other states have held that these ar-
eas are to be available for private leasing from the state and that the lessee will have
the usual rights to exclude and transfer (with some limitations). This difference al-
lowed Professors Agnello and Donnelly to compare the relative efficiency of the pri-
vate and communal property-rights systems. The measure of efficiency they used was
labor productivity (output per person-hour in oyster fishing). Their finding was that
labor was much more productively employed in the privately leased oyster beds than
in the communal oyster beds. Put dramatically, the authors of this study concluded
that if all oyster beds had been privately leased in 1969, the average oyster harvester’s

140 C H A P T E R 5 Topics in the Economics of Property Law

income would have been 50 percent higher than it was. That implies a sizable welfare
loss due to public ownership.

The public oyster beds are an example of the depletion of an open-access resource
by overuse, which is called “the tragedy of the commons.”26 Open access to a con-
gested natural resource has a remorseless logic with a terrible ending, like a Greek
tragedy. There were two clear correctives to the problem: Turn ownership of the re-
source over to an individual (who would then have the appropriate incentive to invest
in its preservation or use and to exclude others from using it) or devise an enforceable
and effective method of restricting access to the common resource.27

26 G. Hardin, The Tragedy of the Commons, 162 SCIENCE 1243 (1968).
27 See ELINOR OSTROM, GOVERNING THE COMMONS: THE EVOLUTION OF INSTITUTIONS FOR ACTION (1990).

Commons and Anticommons

Instead of a tragedy of the commons, the breakup of the Soviet Union in the early 1990s
exposed the symmetrically opposite problem of property rights.28 Rather than too few property
interests—the problem of the commons—there were too many property interests. How did this
come to be? Private property interests were largely unknown during the 70 years of communist
rule, and people came to have ownership claims to resources in idiosyncratic ways. So, for exam-
ple, a large apartment with many rooms, which had been privately owned before the 1917
Revolution, had come to be home to several different families. Each family might occupy one of
the rooms of the apartment and share the use of the kitchen and bathroom. When communism
ended, these families thought that they had continuing ownership claims to their individual
rooms and the common spaces. Suppose that if integrated into an apartment for a single owner,
the apartment—or komunalka, as it was called—would be worth $500,000. Assume that there
are currently four tenant families, each occupying one room and sharing use of the common
spaces. If sold separately, the interests of the tenants would fetch, we assume, $25,000—or
$100,000 in total. Converting the komunalka into a single apartment would create $400,000 in
value. But it was frequently the case that the costs of assembling the individual tenant interests
into the more valuable whole were so great as to preclude the more valuable use of the resource.

The tragedy of the anticommons occurs when multiple owners are each endowed with the
right to exclude others from a scarce resource, and no one has an effective privilege of use.
Property interests can be so finely divided as to impose significant assembly costs on later users
who would like to consolidate the property interests into a more valuable whole. Heller and oth-
ers have argued that precisely this anticommons problem arises in biomedical research.29 We
shall see an additional example in the box on the public domain later in this chapter. The com-
mons and the anticommons suggest symmetric problems of “under-propertization” and “over-
propertization.” Just as the porridge of the three bears could be too hot or too cold or just right,
so, too, the law can define property interests too finely or not at all or in just the right measure.

28 See Michael Heller, The Tragedy of the Anticommons: Property in the Transition from Marx to Market,
111 HARV. L. REV. 621 (1998).

29 Michael A. Heller & Rebecca Eisenberg, Can Patents Deter Innovation?: The Anticommons in
Biomedical Research, 280 SCIENCE 698 (1998).

I. What Can Be Privately Owned? 141

We have discussed the easy case in which private ownership can separate utility
and production functions and in which externalities are private. A more difficult case
for choosing between public and private ownership arises when production and utility
functions of many owners are interdependent and externalities are public. To address
this problem through private ownership, the affected parties must bargain with each
other, and the transaction costs are prohibitive. Public ownership is a possible solution.
Instead of unstructured bargaining and a requirement that everyone agree, the switch
from private to public ownership substitutes structured bargaining and a collective-
choice principle, such as majority rule.

To illustrate, consider pasture land in the mountains of Iceland.30 Dividing the moun-
tain pasture among individual owners would require fencing it, which is prohibitively ex-
pensive. Instead, the highland pasture is held in common, with each village owning
different pastures that are separated by natural features, such as lakes and mountain peaks.
If each person in the village could place as many sheep as he or she wanted in the com-
mon pasture, the meadows might be destroyed and eroded by overuse. In fact, the com-
mon pastures in the mountains of Iceland have not been overused and destroyed because
the villages have effective systems of governance. They have adopted rules to protect and
preserve the common pasture. The sheep are grazed in common pasture in the mountains
during the summer and then returned to individual farms in the valleys during the winter.
The total number of sheep allowed in the mountain pasture during the summer is adjusted
to its carrying capacity. Each member of the village receives a share of the total in propor-
tion to the amount of farmland where he or she raises hay to feed the sheep in the winter.31

Some discussions of the superiority of private ownership over public ownership
equate public ownership with open access to resources. This equation is too simple. In
fact, the general public does not have free access to most public property. To illustrate,
the national parks in the United States are publicly owned, but a fee is charged to enter;
many activities require reservations in advance (a form of rationing by time), and no
one can graze animals or cut wood. The tragedy of the commons, in its fully disastrous
form, requires a political paralysis that prevents government from stopping the destruc-
tion of a resource. This paralysis seems to have reached an advanced stage for some re-
sources, such as fisheries. For other resources, there are symptoms of paralysis, but not
the full disaster. For example, the federal government owns vast lands in the American
West and sells permits for grazing, forestry, and mining on these lands. The federal do-
main is inefficiently managed. As a result, the environment has deteriorated.32

Communism’s collapse in Eastern Europe identified a kind of property problem that
had gone unnoticed. Many shops in Moscow remained closed for several years while
busy street kiosks appeared on the street in front of them. Potentially profitable shops
remained closed because too many people had the legal or effective power to prevent

30 See the discussion of common mountain pastures in Iceland in THRAINN EGGERTSSON, ECONOMIC BEHAVIOR

AND INSTITUTIONS (1990).

32 For an introduction to federal ownership of American land, see MARION CLAWSON, THE FEDERAL LANDS

REVISITED (1983).

31 Professor Elinor Ostrom won the 2009 Nobel Prize in Economics for her studies of governance systems of
public and common resources.

142 C H A P T E R 5 Topics in the Economics of Property Law

anyone from using them. Multiple vetoes resulted from the overhang of socialist laws
enacted under the communist regime. The situation where everyone could prevent any-
one from using a Moscow shop is the mirror image of the sea where no one could pre-
vent anyone from fishing. The problem of the sea was already called the “tragedy of the
commons,” so the problem of the Moscow shops was named the “tragedy of the anti-
commons.” Once an anticommons emerges, collecting rights into usable private prop-
erty bundles can be brutal and slow.

Private ownership assigns each resource to a person who owns it, and the owner can
control access by excluding users. Private owners must bear the cost of boundary main-
tenance. Private ownership works well when production and utility functions are separa-
ble or externalities affect few people who can bargain with each other. Public ownership
comes in three forms. First, open access allows everyone to use a resource, and no one
can exclude anyone from using it. Nothing is spent on boundary maintenance. Open
access works well when the resource is uncongested, but congestion causes tragic over-
use. Second, political control allows lawmakers or regulators to impose rules concern-
ing access. Limited access is the most common rule for the state’s property, including
public lands. Third, the opposite of open access is unanimous consent, which allows no
one access unless everyone agrees. The need for unanimous consent among multiple
owners causes tragic underuse. In special circumstances where the aim is to preserve
a resource in its unused condition, underuse is serendipitous rather than tragic.

It would be surprising if a small, homogeneous village in Iceland were paralyzed polit-
ically to the point of being unable to manage public resources. However, a large, heteroge-
neous country such as the United States faces far more difficult problems in managing
public resources. One solution is to reduce public ownership by selling federally owned
land. The market value of the products yielded by lands in the American West would surely
be higher if the land currently under public control were transferred to private control.

This argument, however, is unlikely to persuade those who want to see the wilder-
ness underutilized. Most ecologists believe that public land should not be managed with
the aim of maximizing the market value that it yields. Everyone tends to think that some
things are more valuable than wealth (at least at the margin), such as liberty or truth; for
some people, wilderness is such a value. People who love liberty would never decide
whether persons have the right to speak by asking whether people would pay more to
hear them or to shut them up. Similarly, those who love the wilderness would never de-
cide whether to build condominiums on the nesting site of the California condors by ask-
ing whether developers would pay more for the land than would the ecologists.
Ecologists usually oppose the sale of public lands to private interests because their aim
is to limit development rather than to increase yield. Given the scope of disagreement
between ecologists and developers, it seems certain that vast resources will be used up
in political disputes over the governance of public lands in the western United States.

QUESTION 5.14: Cooperative enterprises are collectively owned, and their
affairs are directed through shared governance. Use the preceding theory to
discuss the management of some cooperative enterprises with which you are
familiar, such as a cooperative dairy, a cooperative apartment building, an
Israeli kibbutz, a Hutterite farm, a commune, and so on.

II. How are Property Rights Established and Verified? 143

II. How are Property Rights Established and Verified?
As explained in the preceding chapter, the clear delineation of property rights typi-

cally facilitates bargaining and voluntary exchange. If property rights are unclear, the
parties have an incentive to bargain and clarify them. However, delineation and en-
forcement of property rights is costly. It is necessary, consequently, to balance the ben-
efit from delineating property rights against the costs. In this section we consider how
law strikes the balance.

A. Establishing Property Rights Over Fugitive Property:
First Possession versus Tied Ownership
The problem of defining property rights seems straightforward for objects like land

and houses, which have definite boundaries and stay put. But what about objects that
move around or have indefinite boundaries, like natural gas or wild animals? “Fugitive
property,” as such things are called, creates a legal problem as illustrated by the case of
Hammonds v. Central Kentucky Natural Gas Co., 255 Ky. 685, 75 S.W.2d 204 (Court
of Appeal of Kentucky, 1934). The Central Kentucky Natural Gas Company leased
tracts of land above large deposits of natural gas. Some of the leased tracts were sepa-
rated from one another by land that the company did not own or lease. The geological
dome of natural gas from which the company drew its supply lay partially under the
leased land and partially under unleased land. Hammonds owned 54 acres of land that
lay above the geological dome tapped by the Central Kentucky Natural Gas Company,
but she had not let the subsurface rights in her land to the company. When the Central
Kentucky Natural Gas Company extracted natural gas and oil from the dome, she sued
the company on the theory that some of the natural gas that was under her land had
been wrongfully appropriated by the defendant.

It is difficult in this case, if not impossible, to identify which natural gas came from
under unleased land and which came from under leased land. Two general principles
can solve the problem of establishing ownership:

1. First possession: oil and gas are not the property of anyone until reduced
to actual possession by extraction, or

2. Tied ownership: the owner of the surface has the exclusive right to subsur-
face deposits.

Under the first rule, the Central Kentucky Natural Gas Company was entitled to extract
all the natural gas from the dome, regardless of whether it held the surface rights. But
under the second rule, the Central Kentucky Natural Gas Company was only entitled to
extract the natural gas under the ground that it owned or leased.

The consequences of these two rules for the efficient exploration and extraction of
natural gas are very different. According to the first rule, fugitive oil or gas is not
owned by anyone until someone possesses it, and the first person to possess it thereby
becomes the owner. This rule can, consequently, be called the rule of first possession.
The rule of first possession applies the legal maxim “first in time, first in right.” This
rule has been used to establish ownership rights for centuries. To illustrate, in the arid

144 C H A P T E R 5 Topics in the Economics of Property Law

American Southwest, state law allowed a person to obtain a right to water in a stream
by being the first to tap it for use in mining or irrigation. (See the box entitled “Owning
the Ocean” on page 156.) By now, there are few opportunities to claim unpossessed
land or water, but the rule of first possession applies to important forms of intangible
property, such as inventions.

A great advantage of the rule of first possession is that it focuses on a few simple facts,
so it is relatively easy and cheap to apply. In the event of a dispute about ownership, deter-
mination of who first possessed the property in question is usually straightforward. For
example, material evidence usually proves who tapped a water supply first. There is, how-
ever, an economic disadvantage of the rule of first possession: it creates an incentive for
some people to preempt others by making uneconomic investments to obtain ownership of
property. The reason why the rule of first possession creates an incentive to invest too
much too early is easily explained. According to the rule of first possession, an appropriate
investment transfers the ownership of a resource to the investor. The owner of a scarce
resource can rent it to others. Rent increases as a resource becomes more scarce. Indeed,
rent is the scarcity value of the resource. Under the rule of first possession, an investment
thus yields two types of benefits to the investor: (1) production (more is produced from
existing resources), and (2) future rent (scarcity value of the resource in the future).

To illustrate, assume that the law allows a person to acquire ownership of “waste”
land by fencing it. Fencing land increases its productivity from, say, grazing cattle on
it. By assumption, fencing the land also transfers ownership to the person who built the
fence. Assume that fencing waste land costs more than the profit from grazing cattle on
it at current prices, but everyone expects the use value of the land to increase as popu-
lation grows in the future. Investors may build useless fences to “preempt” others and
secure title to the land.

Preemptive investment illustrates a general economic principle applicable to the
rule of first possession. When the state awards property rights, people contest vigor-
ously to obtain title. In a contest for title, persons try to get ownership rights transferred
to themselves. Economic efficiency, however, concerns the production of wealth, not
the transfer of it. Investments for the sake of transferring wealth, not producing it, are
socially inefficient.

In technical terms, social efficiency requires investors to invest in a resource until the
marginal cost equals the marginal increase in productive value. The rule of first posses-
sion causes people to invest in a resource until the marginal cost equals the marginal value
of the sum of increased production plus transferred ownership. The transfer effect under
the rule of first possession thus causes over-investment in the activities that the law de-
fines as necessary to obtain legal possession. It is in the self-interest of investors, but not
in the interests of social efficiency, to improve property in order to transfer ownership.

To illustrate, consider the Homestead Act of 1862 in the United States, which
established rules allowing private citizens to acquire up to 160 acres of public lands in
the West. The act required claimants to fulfill certain requirements before they
acquired title. For example, the claimant had to file an affidavit swearing that he or
she was either the head of a family or 21 years old, and that the claim was “for the pur-
pose of actual settlement and cultivation, and not, either directly or indirectly, for the
use or benefit of any other person or persons whomsoever.” Moreover, before full title

II. How are Property Rights Established and Verified? 145

33 Thomas A. Merrill, “Establishing Ownership: First Possession versus Accession.” BERKELEY LAW AND

ECONOMICS WORKSHOP (26 February 2007).

was acquired for $1.25 per acre, the claimant had to reside on the claim for 6 months
and make “suitable” improvements on the land. These requirements were meant to min-
imize transfer effects and to encourage production. In practice, however, the require-
ments were fleetingly enforced (as was usually the case with the residence requirement)
and easily evaded (as when “suitable” improvements consisted of placing miniature
houses—really large doll houses—on the claim). The occupation and development of
the American frontier occurred at a faster pace than competitive markets or a strictly
enforced Homestead Act would have produced.

In contrast to the rule of first possession, there is no gap in ownership under the
second rule for fugitive gas, according to which all the gas under the ground already
belongs to the people who own the surface. By extension, the second rule suggests that
wild animals belong to the owners of some piece of land, such as the land where the
wild animal was born. Ownership of fish and other marine resources should perhaps be
tied to ownership of the ocean floor. In general, the second rule, called the rule of tied
ownership, ties ownership of fugitive property to settled property.

The common and civil law often tie ownership by applying the principle of
accession. According to this principle, a new thing is owned by the owner of the prox-
imate or prominent property. Thus, a newborn calf belongs to the owner of the mother
cow, new land created by a shift in a river belongs to the owner of the river’s bank;
the owner of a brand name has an exclusive right to use it in an Internet domain
name; the owner of copyright has an exclusive right to adapt the work to another
medium; an owner of an apartment also owns any fixtures that a tenant attaches to the
walls; a new business opportunity discovered by a corporate employee in the course
of work belongs to the corporation; and a carpenter who unknowingly uses someone
else’s wood to make a barrel owns it (but he must pay restitution to the wood’s owner).33

Tying ownership of fugitive property to settled property avoids preemptive invest-
ment so long as the ownership claims in the resource to which the fugitive property is
tied are already established. To illustrate, all the gas is already owned under the second
rule because all the surface rights are already owned, so the rule does not provide an
incentive to acquire ownership by extracting too much gas too soon. Similarly, if
salmon were the property of the people who own the streams where they spawn, the
owners would not deplete the salmon by catching too many of them.

The problem with the second rule, as illustrated by the facts in Hammonds, is the
difficulty of establishing and verifying ownership rights. The homogeneity of natural
gas and its dispersion in caverns makes proving its original underground location diffi-
cult and costly.

Our analysis of fugitive resources reveals a common trade-off in property law:

Rules that tie ownership to possession have the advantage of being easy to administer
and the disadvantage of providing incentives for uneconomic investment in possessory
acts, whereas rules that allow ownership without possession have the advantage of
avoiding preemptive investment and the disadvantage of being costly to administer.

146 C H A P T E R 5 Topics in the Economics of Property Law

Choosing the more efficient rule in a case such as Hammonds requires balancing
the incentive to overinvest under the rule of first possession against the cost of ad-
ministering and enforcing ownership without possession. (Besides first possession
and tied possession, other ways of allocating initial rights include auctions, lotteries,
and preferences based on attributes such as needs, accomplishments, ethnicity, and
gender.)

QUESTION 5.15: Here is the critical part of the case of Pierson v. Post,34

“ . . . Post, being in possession of certain dogs and hounds under his command, did,
‘on a certain wild and uninhabited, unpossessed and waste land, called the beach, find
and start one of those noxious beasts called a fox,’ and whilst there hunting, chasing
and pursuing the same with his dogs and hounds, and when in view thereof, Pierson,
well knowing the fox was so hunted and pursued, did, in the sight of Post, to prevent
his catching the same, kill and carry it off. A verdict having been rendered for [Post,
who was] the plaintiff below, [Pierson appealed] . . . However uncourteous or unkind
the conduct of Pierson towards Post, in this instance, may have been, yet his act was
productive of no injury or damage for which a legal remedy can be applied. We are of
opinion the judgment below was erroneous, and ought to be reversed.”

Does this decision implement a principle of tied ownership or a principle
of first possession? Note that the case, which is a staple in introductory courses
on property law in American universities, seems irrelevant to modern condi-
tions because first possession of foxes apparently does not lead to capturing
too many of them too soon.

Economic analysis suggests that it should not be because of concerns about
which hunter owns a fox. Explain the costs and benefits to weigh in an efficiency
analysis of this case.

QUESTION 5.16: Can you make any sense of the proposition that the rule
of first possession is a principle of “natural justice”?

B. When to Privatize Open-Access Resources:
Congestion versus Boundary Maintenance
We have discussed various examples from history of unowned resources that

become private property. When do unowned resources become owned? Economics
suggests an answer.

The rule of first possession often applies when property is owned in common and
accessible to the public. Property that is accessible for use by a broad public is called
an open access resource. To illustrate, the seas are common property to which the pub-
lic has access. In many cases, the fish and mammals in the sea can be owned by who-
ever catches them. Consequently, fish and marine mammals have been hunted far

34 Cal. R. 175, 2 Am. Dec. 264 (Supreme Court of New York, 1805).

II. How are Property Rights Established and Verified? 147

35 See T. Eggertsson, Analyzing Institutional Successes and Failures: A Millennium of Common Mountain
Pastures in Iceland, 12 INTN’L. REV. LAW & ECON. 423 (1992).

beyond the economic level, some to the brink of extinction. Similarly, in much of the
world, common hunting land is over-hunted, common pasture land is over-grazed, and
public forests are over-harvested. Much of the world’s soil erosion and forest depletion
is caused by the open-access rule.

Some technical terms follow to help explain the economic irrationality of the situ-
ation. The “maximum sustainable yield” is the largest yield sustainable in the long run.
To maximize the yield, the application of labor and capital must expand until the mar-
ginal products of labor and capital are zero. All of the world’s major fisheries are cur-
rently fished beyond the maximum sustainable yield, which means that the marginal
product of labor and capital is negative. In these circumstances, the catch on the fish-
eries would increase simply by making less effort and reducing expenditures on labor
and capital. Similarly, the yield on many open-access forests would increase by invest-
ing less effort and cutting fewer trees, and the yield on many open-access pastures
would increase by investing less effort and keeping fewer animals. Overused fisheries,
forests, and pastures are analogous to a factory with so many workers that they get in
each others’ way and slow each other down, so the factory’s total product would in-
crease merely by reducing its total employment. Nothing could be more irrational than
assigning people to work at jobs with negative productivity.

Preventing overuse of common resources involves controlling use by means other
than the open-access rule. Tied ownership is one method. For example, to prevent over-
grazing of common pastures, small communities in Iceland traditionally tied access to
common pastures to production on private pastures. Specifically, farmers were allowed
to graze animals in the common, high lands in the summer according to a formula
based on the number of animals each farmer sustained in the winter from hay grown on
private pastures in low lands.35

Another method to prevent overuse is privatization, which means in this context
converting from public to private ownership. To illustrate, many people could home-
stead land, fish in the sea, or gather coral from reefs. In contrast, a private owner can
exclude others from using his or her resource. Granting private property rights over
land, whales, or elephants would close access by limiting it to the owner. Thus, home-
steading land converts it from public to private ownership; some salmon streams have
been converted to private ownership; and some villages have been given ownership of
coral reefs.

The conversion from common ownership to private ownership involves this trade-
off: A rule of open access causes over-use of a resource, whereas private property rights
require costly exclusion of non-owners. This formulation suggests when an economi-
cally rational society will change the rule of law for a resource from open access to pri-
vate ownership. When the resource is uncongested and boundary maintenance is
expensive, open access is cheaper than private ownership. As time passes, however,
congestion may increase, and the technology of boundary maintenance may improve.
Eventually, a point may be reached where private ownership is cheaper than open

148 C H A P T E R 5 Topics in the Economics of Property Law

Owning the Ocean

Water covers 70 percent of the Earth’s surface in the form of oceans; yet, almost all of that vast
amount of water is unaffected by well-defined property rights. In the late sixteenth and early
seventeenth centuries, the great voyages of discovery and the resulting sea-borne empires in
Europe necessitated internationally accepted rules on rights to use the ocean. These rights were
first catalogued in the famous Mare Liberum of Hugo Grotius of Holland. He noted that the
“sea, since it is as incapable of being seized as the air, cannot have been attached to the pos-
sessions of any particular nation.” In the system that Grotius suggested and that prevailed in in-
ternational law for nearly 300 years, each nation was to have exclusive rights to the use of the
ocean within three miles of its shoreline, with that area to be called the “territorial seas.” (The
three-mile distance was not picked at random; it was the distance that an early seventeenth-
century cannonball could carry.) Beyond the three-mile limit, Grotius urged that the “high seas”
should be a common resource from which none, save pirates, could legitimately be excluded.

Increasing use of the high seas in the early and mid-nineteenth century led to the re-
placement of the doctrine of “free use” with that of “reasonable use.” After World War II,
the increasing importance of shipping, fishing, offshore oil and gas deposits, and seabed min-
ing caused the legal system of ocean rights to crumble. In 1945 President Truman announced
that the United States’ exclusive rights to subaqueous organic resources—such as oil and nat-
ural gas—extended to the edge of the continental shelf or margin, an area that stretched
200 miles from the Atlantic Coast of the United States. Other nations quickly made similar
claims. Unlike these unilateral actions, attempts at international cooperation have achieved
mixed results.

access. An economically rational society will privatize a resource at the point in time
where boundary maintenance costs less than the waste from overuse of the resource.36

This theory makes definite predictions about privatization. For example, it predicts
that the invention of barbed wire, which lowered the cost of boundary maintenance in
areas where there were few fencing materials, would promote the privatization of pub-
lic lands in the American West. As another example, it predicts that property rights will
be created in the electromagnetic spectrum when broadcasters begin to interfere with
each other. The predictions of this theory are confirmed by some facts and discon-
firmed by others. Apparently, societies are often rational, as the theory assumes, but not
perfectly rational. Politics leads to bargains and compromises that violate the require-
ments of economic efficiency. For examples of these compromises, read the box enti-
tled “Owning the Ocean.”

36 This is the central point made by Harold Demsetz in Toward a Theory of Property Rights, 57 AM. ECON.
REV. 347 (1967). He argues, for example, that American Indians did not establish property rights in land
when the costs of administering the rules exceeded the benefits from private ownership. Proceeding along
these lines, he tries to explain why certain North American Indian tribes, such as those in the Northeast,
whose principal economic activity was trapping animals for their fur, developed a notion of property rights
and others, such as the Plains Indians, whose principal resource was the migratory buffalo, did not. The
extent to which his arguments can be squared with history or anthropology is still open to question.

II. How are Property Rights Established and Verified? 149

To illustrate, when the third United Nations Convention on the Law of the Sea (UNCLOS)
convened in 1973, there was widespread agreement that the territorial sea would be estab-
lished at the 12-mile limit and that there should be an “exclusive economic zone,” largely but
not completely controlled by the coastal state, stretching to 200 miles beyond the shoreline,
the general extent of the continental shelf.

There was not general agreement on what to do with property rights to the areas be-
yond this 200-mile limit, and it was the disposition of these areas that raised the really hard
issues. The developed countries urged a private-property-rights-based system of develop-
ment, whereas the developing countries offered a common-property-rights system. In the end
a compromise, called the parallel system, was agreed on. There would be both private devel-
opment and a UN-funded and UN-operated company, called the “Enterprise.” In order to give
the Enterprise the ability to compete with the more advanced countries of the developed
world, an International Seabed Authority (ISA) would be created to allocate rights to mine the
oceans. The conference specified an ingenious variant of the “I cut, you choose” method of
cake-cutting in order to allocate mining rights. Before it could begin operation, a private or
state organization had to submit to the ISA two prospective sites of operations. The Authority
would then choose one of those sites for later development by the Enterprise and allow the
applicant to proceed with the mining of the other.

The United States refused to sign the final treaty, although 117 countries eventually signed
it in December, 1982. Over time, the U.S. objections to the missing provisions of UNCLOS III
have faded or been proven unfounded. The treaty went into effect in 1994. The U.S. has signed
the treaty, but Congress has not ratified it.

QUESTION 5.17: In what ways do these historical developments respond to efficiency,
and to what extent do they respond to political power and distribution?

QUESTION 5.18: Read the following account of the history of water law and
discuss whether the law appears to have evolved toward economic efficiency.

Water has always been one of the most valuable natural resources, but because it
tends to run away, there have always been problems in defining and assigning property
rights in water. Centuries ago in England, the general rule was that rights were vested
in the “riparian owner,” that is, in the person who owned the land on the bank of the
river. The riparian owner’s principal right was to a flow of water past his land. It would
be a violation of someone else’s rights for an upstream user to use the water that passed
by his property in such a way as to reduce the flow to downstream users. The upstream
user could not, therefore, divert so much of the water to his own use that the flow was
significantly diminished for those downstream. A riparian was restricted in his ability
to sell water to nonriparians (that is, people who do not own land along the water).

However, in the nineteenth century, this legal arrangement had to be altered because
industrial demand on the natural flow of a river frequently exceeded the supply. In the
eastern United States, these issues were resolved by elaborating the natural-flow theory
of water rights that had been adopted from the English common law. An alternative
theory of water rights appeared in the western United States. Under the reasonable-use
theory, the riparian owner is entitled to use the water flow in any reasonable way. It was

150 C H A P T E R 5 Topics in the Economics of Property Law

deemed reasonable for one owner to use all of the water in a stream or lake when oth-
ers are making no use of it. Under the reasonable-use theory, a riparian owner does not
have a right to the natural water flow. Furthermore, a riparian owner may transfer rights
to nonriparians.

C. Recording and Transferring Title: Verification
Costs versus Registration Costs
Branding cattle, stamping a serial number on an automobile engine, stenciling a

Social Security number on a TV—these are some ways that private persons try to prove
their ownership of valuable goods. In addition to these private remedies, the state some-
times provides registries of ownership. Thus, trademarks are registered to avoid dupli-
cation or overlap. Brand inspectors employed by the state or private companies may
police violations. Despite these devices, people sometimes “buy” goods that were not
the seller’s to sell. This section concerns verifying ownership and remedies when a
good is “sold” without the owner’s permission.

Suppose you decide to fulfill a lifelong dream and buy a farm. You find a parcel in
the country that you like and approach the farmer who is living there. After discussing
the parcel’s boundaries, fertility, and drainage, the farmer offers to sell the land at an
attractive price. You shake hands to seal the agreement. The next week you return with
a check, hand it over to the farmer, and shortly thereafter move onto the property. Two
weeks later, a man knocks at the cottage door, announces that he is the owner of the
property, and explains that he has come to evict the nefarious tenant who rented the cot-
tage in which you are living. At this point you recall the joke that begins: “Hey buddy,
how would you like to buy the Brooklyn Bridge?”

When you buy property, you should ascertain the rightful owner and deal with him
or her. A reliable and inexpensive method for determining ownership prevents fraudu-
lent conveyances, such as tenants representing themselves as owners. There are various
ways to create a record of ownership. Consider the story—presumably apocryphal—of
“recording” title in England in the Middle Ages, when few people could read. It is said
that the seller handed the buyer a clod of turf and a twig from the property in a ceremony
before witnesses known as livery of seisin. Then, the adults thrashed a child who had
witnessed the passing of turf and twig severely enough so that the child would remem-
ber that day as long as he or she lived, thus creating a living record of the transfer.

Fortunately, we now have better methods of recording title in land. In the United
States, there is no uniform method of land registration,37 but each of the fifty states has
some system for the public recording of title to land. A change in ownership of real

37 There is an alternative land registration system, known as the Torrens system, after Sir Richard Torrens,
who introduced this simplified mechanism into South Australia in 1858, and that system or something like
it is in use in many parts of the world. In the Torrens system, the state operates a registry and a title insur-
ance fund. Defects in title caused by the state record-keeper are compensated from the insurance fund.
Several of the United States tried the Torrens system, but every one of them has abandoned the system,
because incompetent bookkeeping caused such a drain on the state-operated title insurance funds that
the funds went bankrupt. (See SHELDON KURTZ & HERBERT HOVENKAMP, AMERICAN PROPERTY LAW

1151–1244 [1987].)

II. How are Property Rights Established and Verified? 151

38 You should recognize that this argument in favor of a system of recordation of ownership claims is a
general instance of the Normative Coase Theorem of the last chapter.

property must be recorded in an official registry of deeds, such as the county recorder’s
office. Recording is a formal process, and the records are open to the public. The record
of ownership on file usually contains a formal description of the property’s location, a
list of restrictions that apply to the property, and an account of who has owned the
property at each point in time.

While a system of recording title is maintained for land and a few other valuable
items, like automobiles, there is no such system for most goods. In most exchanges the
buyer does not devote resources to determining whether the seller truly owns what he
or she is selling. For example, you rarely question whether the books you purchase at
the bookstore were rightly the bookstore’s to sell. Your presumption is that whoever
possesses a book rightfully owns it. Further proof of ownership is in the memory of
witnesses to the sale, like the child in the medieval example, or perhaps in a written
sales contract. A system of recording the ownership of books would burden commerce
and impede the efficient movement of goods.

The security of major contracts is strengthened by a system of official witnesses to
the event. Official witnesses, called “notaries,” record the event in an official document
and fix their seal to it. Some U.S. states license many notaries, so their fees are low. At
the other extreme, some countries like Italy restrict notaries to specialized lawyers who
pass difficult exams, perform complicated services far beyond witnessing a document,
and enjoy high monopoly profits, especially in real estate transactions.

We have encountered another trade-off in property law. On the one hand, verifying
title by formal means, such as recording the transfer of a deed, reduces the uncertain-
ties that burden commerce. On the other hand, the verification of title through formal
means is costly. Property law thus has to develop rules that balance the impediments to
commerce created by uncertain ownership against the cost of maintaining a system of
verification. For costly items like houses and cars, the law reduces the uncertainties that
burden commerce by providing a system for recording title, and the law typically forces
all sales through the recording process by refusing to protect unrecorded transactions
in these items. For small transactions, however, the cost of maintaining a system of ver-
ification would exceed the benefit from reduced risk.38

D. Can a Thief Give Good Title?
Let us consider how people respond to laws allocating the responsibility to verify

ownership. Imagine that you have made a shrewd deal for the purchase of a television
from a person whom you met in the parking lot outside a local bar. The seller told you
a tale about his urgent need to raise cash by selling his TV and handed it over from the
trunk of his car. One evening while you are enjoying your new television, the police ar-
rive at your apartment with the person from whom the TV was stolen. Should the law
allow you to keep the TV or require you to return it? This example poses the general
question: if a good is stolen from owner A by thief B, and B disappears with the money
after selling the good to innocent buyer C, does the good belong to A or C?

152 C H A P T E R 5 Topics in the Economics of Property Law

This figure depicts the facts:

This question is answered differently in different jurisdictions. According to the
rule in America, transferors can usually convey only those property rights that they le-
gitimately have. Thus, a person without title cannot convey title to a purchaser.39 In this
example, the thief did not have good title to the television, so he could not give you
good title to it. Instead, title rests with the person from whom the TV was stolen.
According to the American rule, you must return the television set to its owner. You are
entitled to recover your money from the thief (technically, the thief breached his war-
ranty of title), if the thief is caught and has money.

A different rule prevails in much of Europe, where the buyer acquires title by pur-
chasing the good “in good faith.”40 The good-faith requirement means that the buyer
must genuinely believe that the seller owns the good. The good-faith requirement pre-
vents a “fence” of stolen goods from hiding behind the law. The law may also require
the buyer to make reasonable efforts to verify ownership, such as checking that the se-
rial number was not filed off the television. Applied to this example, the European law
presumably permits you to keep the television. The original owner may recover your
money from the thief, if possible.

In general, law must allocate the risk that stolen goods will be bought in good
faith. The American rule places the entire risk on the buyer, whereas the European rule
places that risk on the original owner. The American rule gives buyers an extra incen-
tive to verify that the seller is truly the owner. The European rule gives owners an extra
incentive to protect their property against theft. One of these rules is more efficient in
the sense of imposing a lower burden on commerce and promoting the voluntary ex-
change of property.

Which rule is it? Here is a method for finding out. Let Co indicate the lowest cost
to the original owner of protecting against theft by, say, engraving his or her Social
Security number on the object. Let CB indicate the lowest cost to the purchaser of veri-
fying that the seller is the owner by, say, confirming this fact with the party from whom
the seller originally obtained the good. For the sake of efficient incentives, liability

39 This is true as a generalization, but there are important exceptions. For example, if a thief steals money
and uses it to buy goods from a merchant, the original owner of the money cannot recover the money from
the merchant. A thief can convey good title to money. Moreover, the Uniform Commercial Code allows
regular dealers in goods sometimes to give better title than they got. Thus, if a television store happens to
have taken possession of and sold a stolen television, the buyer is entitled to presume that the dealer had
good title to the television. Any liability to the true owner of the television lies with the dealer. Can you
suggest an economic reason why this is a sensible rule?

40 Our simplification of the European rule omits nuances in civil law. Thus, rule §935 of the German Code of
Civil Law distinguishes an owner who lost possession of a movable good voluntarily as opposed to invol-
untarily. An owner who lost possession involuntarily has a relatively strong claim against a good faith pur-
chaser of it.

Owner
good good

money
A ThiefB C Buyer

II. How are Property Rights Established and Verified? 153

41 C. Paz-Ares, Seguridad Jurica y Seguridad del Trafico, REV. DE DERECHO MERCANTIL 7–40 (1985).
42 It is also possible to acquire an easement by adverse use of another’s property. For example, someone who

habitually cuts across someone’s property without protest by the owner may acquire the right to continue
cutting across the property.

should fall on the party who can verify ownership at least cost. Thus, the efficiency of
the competing rules may be determined as follows:

1. If it is generally true that Co # CB, then it is more efficient for the good-
faith buyer to acquire good title against the original owner.

2. If it is generally true that Co $ CB, then it is more efficient for the original
owner to retain title against the good-faith buyer.

Unfortunately, the absence of empirical evidence about the values of Co and
CB prevents us from answering decisively whether one rule is better than the other.
Indeed, the lack of evidence also prevents different countries from identifying the
more efficient rule and adopting it. However, the example of Spain suggests what
is probably the best approach. In Spain, the “American Rule” typically applies
when the thief steals the good from a household and sells to a merchant. In other
words, a Spanish merchant cannot get good title from a thief. Merchants who buy
from a thief encourage thievery by making it more profitable. The Spanish practice
of applying the American Rule to merchants who buy from thieves discourages
merchants from “fencing” stolen goods, thus reducing the profitability of theft. In
Spain, however, the “European Rule” that a buyer can acquire good title from a
thief typically applies when the thief steals the good from a merchant and sells it to
another merchant or a household. Thus, the Spanish practice increases the ease
with which goods circulate among merchants in commerce and passes to the final
consumer.41

E. Breaks in the Chain of Title
Uncertain ownership burdens commerce and causes deep discounting of the value

of an asset by prospective purchasers. Consequently, economic efficiency requires
clearing away uncertainties, or “clouds,” from the title to property. This section briefly
examines how property law removes the clouds that accumulate over titles.

1. Adverse Possession In the preceding chapter we discussed an example in
which Joe Potatoes unwillingly built his house so that two feet of it extended over the
property line onto Fred Parsley’s lot. Recall that Parsley did not discover the trespass
and sue until 10 years had passed. Has Potatoes acquired any right to the part of
Parsley’s property that he has occupied? According to Anglo-American law, he may
have. If the owner “sleeps on his rights,” allowing trespass to age, the trespasser may
acquire ownership of the property.

The relevant legal doctrine is adverse possession. The phrase refers to the fact that
a trespasser’s possession of the land is adverse to the owner’s interest.42 Someone can

154 C H A P T E R 5 Topics in the Economics of Property Law

acquire ownership of another’s property by occupying it for a period of time specified
in a statute, provided the occupation is adverse to the owner’s interests, and the original
owner does not protest or take legal action.43

The economic advantage of adverse possession is that it clears the clouds from ti-
tle and allows property to move to higher-valuing users. To illustrate, assume that you
want to buy a house that was built in 1910 and sold in the years 1925, 1937, and 1963.
Your search of title reveals a confusion in the legal records about whether the sale in
1937 was legal. However, the current owner has resided on the property since 1963
without a legal challenge. The law for this jurisdiction stipulates that adverse posses-
sion for 25 years transfers ownership to the trespasser. The adverse-possession statute
and the current owner’s unchallenged occupancy since 1963 have thus removed the
cloud from the title dating to 1937. In general, a rule for acquiring title by adverse pos-
session lowers the cost of establishing rightful ownership claims by removing the risk
that ownership will be disputed on the basis of the distant past.

Another efficiency justification for adverse possession was emphasized in the past:
adverse possession prevents valuable resources from being left idle for long periods of
time by specifying procedures for a productive user to take title from an unproductive
user. Under such a rule, persons who neglect to monitor their property boundaries run
the risk of losing idle parts of them to someone who makes use of them. In this respect
the rule tends to move property from idleness to productive use. Sometimes squatters
have acquired land from absentee owners through adverse possession. In the American
West, settlers historically acquired much Indian land through adverse possession. The
settlers viewed themselves as putting the land to a higher use, whereas the Indians
viewed the settlers as thieves.

Besides the two types of economic benefit, adverse possession has a cost. The cost
is that owners must actively monitor their land to eject trespassers who might otherwise
become owners through adverse possession. Without adverse-possession statutes, own-
ers might reduce monitoring costs and more trespassers would enjoy using other peo-
ple’s land.

QUESTION 5.19: Apply the concept of adverse possession to the electro-
magnetic spectrum.

43 To be precise, traditional scholarship distinguishes four conditions that adverse possession must satisfy:

1. The adverse possessor must have actually entered the contested property and have assumed exclusive
possession.

2. That possession must be “open and notorious.” This phrase means that the trespass must not be done in
secret; an alert owner should be able to detect it.

3. The trespasser’s possession must be adverse or hostile and under a “claim of right.” This condition
requires the trespass to be inconsistent with the owner’s use rights and against the owner’s interests.

4. Finally, the trespass must be continuous for a statutorily specified period. Some states in the American
West also require the adverse possessor to pay property taxes for a statutorily specified period before
acquiring title. See LAWRENCE FRIEDMAN, A HISTORY OF AMERICAN LAW 360–361 (2d ed. 1985). Note
that these conditions do not inquire into the intentions of the adverse possessor. Despite this, there is
evidence that courts are more likely to apply the adverse-possession rule when the trespass is acciden-
tal. See Richard Helmholz, Adverse Possession and Subjective Intent, 61 WASH. U. L. Q. 331 (1983).

II. How are Property Rights Established and Verified? 155

QUESTION 5.20: Why do you think that the statutory time period for ad-
verse possession tends to be short in states like Oklahoma where Indians
owned a lot of land?

QUESTION 5.21: Suppose the statute of limitations for adverse possession
is 10 years. After 9.9 years of trespass owners retain full rights, but after
10 years of trespass owners lose all of their rights. Instead of owners losing
their rights abruptly at the end of 10 years, the statute could be written so that
the rights depreciate gradually over time. For example, the trespasser could be
granted a 10 percent interest in the property for each year of adverse posses-
sion, so that after one year the trespasser would own 10 per cent of it and after
10 years the trespasser would own all of it. Compare the efficiency of the
“discontinuous rule” and the “continuous rule.”

2. Estray Statutes Suppose that while strolling down an alley in Manhattan you
stumble over a brown paper bag. Opening the bag, you find that it contains a diamond
brooch. Naturally, you would like to claim it for your own. But clearly someone has
lost it. Are you entitled to keep it if the owner does not demand it back after a reason-
able period of time? Are you obligated to make efforts to locate the owner, say, by ad-
vertising in the paper? Who owns property that has been abandoned, lost, or mislaid?
Estray statutes answer these questions.

A typical estray statute in the United States stipulates a procedure for the finder to
acquire ownership of lost or abandoned property. If the property exceeds a stipulated
value, the finder may have to appear before a court official and sign a document con-
cerning the facts about the property found. The court official then places an advertise-
ment concerning the found item. If the owner does not appear to claim it within a
stipulated time period (for example, one year), the finder becomes the owner. A finder
who keeps the item without complying with the statute is subject to a fine.

Like registering title, estray statutes discourage the theft of property. Given an
estray statute, a thief who is caught with another’s property cannot avoid liability by
claiming that he or she found it. (“Where did you get that watch?” Sherlock asked the
suspect. “It fell off the back of a truck,” he replied.) Thus, an estray statute helps to dis-
tinguish a good-faith finder from a thief. Like adverse-possession rules, estray statutes
tend to clear the clouds from title and transfer property to productive users. Like
adverse-possession rules, estray statutes also provide an incentive for owners to moni-
tor their property. Finally, estray statutes induce the dissemination of information by
finders and thus reduce the search costs of owners who lose or mislay their property.

QUESTION 5.22: If the value of a lost object is low enough, the estray
statutes do not apply. Consequently, the finder has no legal obligation to ad-
vertise. Discuss the costs that need to be balanced to the most efficient lower
bound in the value of a lost object for purposes of the estray statutes.

QUESTION 5.23: In admiralty law, there have to be rules for allocating
ownership rights to property lost at sea. In the United States, the finder of an

abandoned ship is generally awarded ownership, but in some cases the gov-
ernment takes possession of abandoned ships in its waters. Where that latter
condition holds, a salvor (that is, one who salvages an abandoned ship) is
usually entitled to a salvage award determined by the court.

Does this practice of making awards to salvors encourage dishonesty, or
does it attract an efficient number of resources into the business of searching
for lost ships? Is the system of awarding complete ownership rights to the
finder more or less efficient than the award-to-salvors system?

III. What May Owners Do with Their Property?
What may owners do with their property? In this section we analyze some tradi-

tional restrictions on property rights. We postpone discussing modern government reg-
ulations such as zoning ordinances till the final section of the chapter.

A. Bequests and Inheritances: Circumvention
Costs and Depletion Costs
In a feudal or tribal world, law typically stipulates the heirs to land, rather than the

owner choosing heirs. To illustrate, the eldest son inherited all of his father’s land in
medieval England,44 and in matrilineal tribes the land is often inherited by the niece
from her aunt. Furthermore, feudal and tribal societies typically restrict the sale of land.
As law modernizes, owners increase their power to stipulate the terms of inheritance
and sales. The law in Western countries has evolved over centuries toward more free-
dom for the owner to specify who may have the property after his or her death and what
they may do with it. We discuss briefly the economic analysis of this trend.

Any restriction on the owner’s choices creates an incentive to circumvent it. To illus-
trate, imagine an owner who wants to bequeath her land to a particular friend, and imag-
ine that the law will award the property to someone else. The owner can circumvent the
law, say, by transferring title to the friend today and leasing it back for $1 per year until
her death. Circumventing the law usually requires the assistance of a good lawyer. In gen-
eral, owners use costly legal resources to circumvent restrictions on the use of property.

Now change the example and imagine that tight laws and costly lawyers prevent
the owner from circumventing restrictions on bequests. Because her desire to designate
her heir was frustrated, the owner may deplete her property before she dies. For exam-
ple, she might cut timber prematurely, or exhaust the soil’s fertility by intensive farm-
ing, or postpone needed improvements to buildings. In general, rules that restrict
transfer undermine the owner’s incentive to maximize the value of the property.

Circumvention costs and depletion costs provide two reasons for allowing an owner
freedom in transferring property at death. However, these same reasons justify restricting

156 C H A P T E R 5 Topics in the Economics of Property Law

44 In most of England from 1066 (the date of the Norman conquest) until 1925, the general rule for disposing
of real estate on one’s death was that it passed intact to the decedent’s eldest son, a system called
primogeniture. Testators were not free to alter this rule except under very narrow circumstances.

III. What May Owners Do with Their Property? 157

48 This account of the rule against perpetuities is roughly, but not exactly correct. The “life in being” des-
ignated as the “measuring life” does not have to be that of the daughter. It could, for example, be the
first child born in Kinshasa the month before the testator’s death. The rule, to be brief, is extremely
complicated—so complicated that it invites creativity to avoid it.

the freedom of an owner in special circumstances. Most property rights live forever, but all
owners die. Sometimes one generation of owners wants to limit the discretionary power of
subsequent owners. To illustrate, suppose that I own my family’s ancestral home,
Blackacre, and I stipulate in my will that no one will ever use Blackacre for purposes other
than as a residence. Subsequently, I die and my heir wants to develop Blackacre into a golf
course. Should the law enforce the restrictions in my will or set it aside and allow my heir
to build a golf course? If the law routinely sets aside such restrictions, then I have an in-
centive to deplete the resource or circumvent the law prior to my death. If the law enforces
such restrictions, then my wishes may be fulfilled but at the social cost of making it diffi-
cult, if not impossible, to move Blackacre to a higher-valued use than its use as a residence.

In the preceding example, the owner apparently wants to restrict future uses of
Blackacre for his own, perfectly legitimate reasons. In other examples, an owner creates a
trust (called a “spendthrift” trust) to protect someone from his or her own bad judgment,45

or a bequest attempts to keep property in the family forever,46 or a restrictive covenant at-
tempts to channel future sales to certain classes of buyers.47 In general, the principle that
the current owner should be free to structure transactions as he or she wishes runs up
against a difficulty when the owner wants to restrict future owners. In these cases, a con-
flict exists between the freedom of sequential owners of the same property. Any reduc-
tion in the freedom of any owner in the sequence may cause economic waste, regardless
of whether the reduction in freedom comes from law or a private transaction.

English common law responded to these facts generally by being skeptical of “re-
straints on alienation,” as they are called, and specifically in the case of bequest by a
complicated law called the rule against perpetuities. The rule imposes a time limit on
property restrictions imposed by the terms of a gift, sale, bequest, or other transaction.
Instead of lasting in perpetuity, restrictions automatically lapse when a legal time limit
expires. The legal time limit has the curious formulation “lives-in-being plus 21 years.”
To illustrate its meaning, assume that my only child is an unmarried daughter, and I
stipulate in my will that she will inherit my ancestral home, Blackacre, on the condi-
tion that it never be used except as a residence. According to the rule, the restriction
must ordinarily lapse 21 years after my daughter’s death.48

Notice that the rule against perpetuities is a “generation-skipping rule.” By this
phrase we mean that it allows an owner to skip over the living generation by restrict-
ing their use of the property, but the property passes unrestricted to the unborn when
they reach the age of 21 and become legal adults. A generation-skipping rule has an
economic rationale. Assume that you must choose a principle concerning the power

45 For example, a trust is created in which the beneficiary receives the interest income from the trust property
but cannot touch the capital until she is middle-aged.

46 For example, the owner leaves instructions that, at his death, his land is to be given to his oldest son, at
whose death the land is to be given to his oldest son, and so on.

47 In the past in America, covenants sometimes blocked future sales to buyers belonging to certain races.

of one generation to impose restrictions on the use of property by subsequent genera-
tions. The principle that you choose will apply to every generation. You know that the
world changes in unpredictable ways, so no restriction is good forever. You also know
that most owners are prudent and benevolent toward their heirs, and a few are foolish
and venal. In effect, you want a principle to protect against an occasional fool in an
unending sequence of owners, given a constantly changing world.

A prudent owner will not restrict a prudent heir, and a prudent owner will restrict a
foolish heir. Given these facts, an attractive principle for you to choose allows each
generation to restrict the next generation, but not subsequent generations. When pru-
dent owners apply this principle, only foolish heirs will be restricted. Furthermore, the
restrictions that prudent owners impose on foolish heirs may prevent the foolish heirs
from imposing restrictions on the next generation. So, the rule against perpetuities ap-
pears to maximize the value of property across generations.

A trust is an organization where one person owns and manages money for the ben-
efit of another. Trusts have different purposes, such as transferring wealth to one’s heirs
while avoiding inheritance taxes. When a person creates and endows a trust, it pays
money to the beneficiary, which is not an inheritance, so no inheritance tax is owed.
Eventually, however, the trust is dissolved, and the tax authorities may recapture part of
the taxes that the trust avoided. To further reduce tax liability, some U.S. states have
enacted laws allowing citizens to create “perpetual trusts” or “dynasty trusts.” Because
they never dissolve, they avoid the tax liabilities triggered by dissolution, but they are
also inconsistent with the rule against perpetuities.

U.S. citizens in one state can establish a trust in another state. States compete to attract
trust business by making favorable laws, especially for avoiding taxes owed to the federal gov-
ernment or other states. Perpetual trusts are an example. Besides avoiding taxes, competition
for trust business can also improve the efficiency of trusts. The management of stock portfo-
lios, which trusts often have, illustrates such an improvement. In the nineteenth century, most
U.S. states adopted a rule making the trustee liable if the portfolio included speculative stocks
that lost their value. This rule caused trustees to buy bonds and very conservative, “blue-chip”
stocks. Low risk, however, characterizes the portfolio as a whole, not each stock in it. In a bal-
anced portfolio, the risk from one stock offsets the risk from another. In technical terms, hold-
ing stock with negatively correlated risk results in low risk for the portfolio as a whole, even
though individual stocks are high risk. Some innovative states responded to these facts by
changing the rules of trust management. Under the revised rules, the trustee who holds a bal-
anced portfolio is not liable for losses caused by a fall in value of individual stocks. This
change in the rule caused trust portfolios to shift away from conservative bonds and toward
more individually risky stocks. States making the change attracted more trust business, which
puts pressure on other states to modernize their rules of trust management.49

158 C H A P T E R 5 Topics in the Economics of Property Law

49 See Max M. Schanzenbach & Robert H. Sitkoff, Did Reform of Prudent Trust Investment Laws Change
Trust Portfolio Allocation?, 50 J. LAW & ECON 681 (2007). See also those authors’ Lawyers, Banks, and
Money: The Revolution in American Trust Law (2011). As another example of competition among juris-
dictions, the trust was developed in the common law, not in civil law. The success of London banks in the
trust business has put pressure on Paris banks to modify French civil law to gain all the advantages of the
trust in English common law.

III. What May Owners Do with Their Property? 159

50 81 Vt. 471, 71 A 188 (Supreme Court of Vermont, 1908).

QUESTION 5.24: Instead of “lives-in-being plus 21 years,” the rule might
be “lives-in-being plus 10 years,” or “lives-in-being plus 35 years.” Compare
these rules as means for “generation-skipping.”

QUESTION 5.25: Suppose that a testator imposes a condition that cannot be
met. For example, the decedent gives her property to be used for a medical
school in Lebanon, Indiana, but after the testator’s death, the State of Indiana
abandons its plans to build a medical school there. In this situation, American
courts apply the doctrine of cy pres (pronounced “see pray” and meaning, in
law French, “so nearly” or “as near as possible”). Under that doctrine the court
will find an alternative condition that is as close as possible to the decedent’s
intentions. For example, the proceeds from the sale of the decedent’s property
in Lebanon, Indiana, might be given to a medical school located somewhere
else. Use the concepts of circumvention costs and depletion costs to provide
an economic rationale for this rule.

QUESTION 5.26: We suggested above that an annually increasing renewal
fee would be an efficient means of setting optimal patent life. Similarly, sup-
pose that owners who wanted to restrict future use of their property had to pay
a fee for each year that the restriction runs. For example, if my will stipulates
that Blackacre should be used exclusively as a residence for 100 years, then I
would have to make provision in my will to pay the state for each year that the
restriction runs. In effect, the state deducts an annual fee from a bequest for a
testator who desires to impose posthumous restrictions on property for a spec-
ified number of years. At what level would you set such a fee? Would it be the
same for all types of conditions and all types of property? Is such a fee more
efficient than the rule against perpetuities?

B. Rights to Use Someone Else’s Property
In general, no one may use another’s property without the permission of the owner.

Use of another’s property without the owner’s permission is an illegal trespass. As we
saw in Chapter 4, this rule and moderate transaction costs induce those who want to use
another’s property to bargain with the owner. Bargaining leads to the use of property
by the party who values it the most, as required for allocative efficiency.

Can someone ever use another’s property lawfully without the owner’s permis-
sion? We have already seen that the “fair use” exception allows one to use copyrighted
material without the owner’s permission—in limited circumstances. (See question 5.11
on page 135). This issue arose in the famous case of Ploof v. Putnam.50 Putnam was
the owner of a small island in Lake Champlain, a large body of water in northern
Vermont. In November, 1904, Ploof was sailing on that lake in a sloop with his wife
and two children when a violent storm arose very suddenly. Ploof needed a safe harbor
quickly, and the nearest one was Putnam’s island. Ploof moored his sloop to a pier on
that island, hoping that his ship and family would be able to ride out the storm in safety.

However, an employee of Putnam’s, fearing that the sloop would damage his em-
ployer’s property by being cast repeatedly against it during the storm, untied the ship
from the pier and pushed it away. The sloop and its passengers were then at the mercy
of the storm. The ship was ultimately driven by the storm onto the shore and wrecked.

Ploof sued Putnam, alleging that the losses to his ship and the injuries to himself
and his family were the result of wrongful action by the defendant, through his em-
ployee. Ploof argued that the storm caused an emergency that justified his trespassing
on the defendant’s property, even without permission. He asked for compensatory dam-
ages for his losses. Putnam replied that every property owner has a right to exclude
trespassers. This principle is so firmly settled, he asserted, that the court should award
him summary judgment without proceeding to trial. The trial judge denied the defen-
dant’s motion for summary judgment, and the defendant appealed. The Supreme Court
of Vermont affirmed the decision and held that private necessity like that of Ploof was
an exception to the general rule against trespass.

In an emergency, one person can use another’s property without permission.
However, the user must compensate the owner for the costs of use. To illustrate, a hiker
who gets lost in a remote wilderness may break into an uninhabited cabin in order to
obtain food and shelter, but the hiker must compensate the owner for damage to the
cabin and food consumed. As another example, X becomes deathly ill during the night,
the only pharmacy in town is closed, and its owner Z is unreachable, so X breaks into
Z’s pharmacy and takes the required medicine. The law will excuse the trespass, but X
must pay damages to Z. As a final example, X, who is about to be murdered by Y, picks
up the nearest heavy object, Z’s valuable china vase, and crashes it over Y’s head,
thereby saving X’s life. X must pay damages to Z for the vase. In brief, the private-
necessity doctrine allows compensated trespass in an emergency.

Bargaining theory rationalizes the private necessity exception to the general rule
against trespass. In an emergency, transaction costs may preclude bargaining. For ex-
ample, the suddenness with which the storm arose precluded Ploof from finding
Putnam and bargaining with him. When bargaining is precluded, voluntary transactions
do not necessarily cause goods to be used by the party who values them the most. A
rule allowing compensated trespass assures that trespass occurs only when its value to
the trespasser exceeds the cost to the owner.51

QUESTION 5.27: An interesting variation on the facts in Ploof occurred
in Vincent v. Lake Erie Transport Co., 109 Minn. 456, 124 N.W. 221
(Supreme Court of Minnesota, 1910). In late November, 1905, the
steamship Reynolds, owned by the defendant, was moored to the plaintiff’s
pier in Duluth and discharging cargo. A storm suddenly arose on Lake
Superior. The Reynolds signaled for a tug to take her away from the pier,

160 C H A P T E R 5 Topics in the Economics of Property Law

51 Suppose that Ploof had found Putnam on the pier and bargained with him. The emergency has conveyed
monopoly power on Putnam, who has the only nearby pier. Given Putnam’s monopoly and Ploof’s desper-
ation, Putnam might demand an exorbitant amount of money for use of the pier. Ploof might promise to
pay it, and then refuse to do so after the emergency passes. Litigation of such “bad-Samaritan contracts” is
discussed later, when we come to the “necessity doctrine” in contract law.

III. What May Owners Do with Their Property? 161

52 For example, see Elizabeth Landes & Richard A. Posner, The Economics of the Baby Shortage, 7 J. LEGAL

STUD. 323 (1978) and J. Robert Pritchard, A Market for Babies?, 34 U. TORONTO L. J. 341 (1984). See also
the 1987 symposium on the economics of selling babies in the Boston University Law Review.

53 See Susan Rose-Ackerman, Inalienability and the Theory of Property Rights, 85 COLUM. L. REV. 931
(1985), Margaret Jane Radin, Market-Inalienability, 100 HARV. L. REV. 1849 (1987), and Richard Epstein,
Why Restrain Alienation?, 85 COLUM. L. REV. 970 (1985).

but because of the storm, none could be found. The ship remained moored
to the pier during the storm. The violence of the storm threw the steamship
repeatedly against the plaintiff’s pier, causing damage in the amount of
$300. The plaintiff asked for that amount. The Lake Erie Transport Co.
contended that its steamship was an involuntary trespasser. The Reynolds
had tried to leave the plaintiff’s property but had not been able to do so
through no fault of its own. The court held that the plaintiff was entitled to
damages. Argue that this holding is efficient.

C. Inalienability
The law forbids the sale of some valuable things, such as body organs, sex,

heroin, children, votes, atomic weapons, or human rights. You cannot even give away
some of these things, such as heroin or your vote in a national election. You cannot
lose some of these things by any legal means, such as your human rights. One mean-
ing of alienation is losing something, especially an intimate part of yourself. In law,
the term inalienable refers to something of yours that you cannot lose by specified
means. Thus, body organs, sex, and children are inalienable by sale, your vote is in-
alienable by sale or gift, and your human rights are inalienable by any means.

The sale of sex or children is prohibited by conventional morality, as well as law.
Many forms of inalienability express conventional morality. Other forms of inalien-
ability, such as the enactment of human rights, express the aspirations of eminent po-
litical theorists. What about economic theorists? What have they had to say about the
efficiency of inalienability? Occasionally, a regulation increases the efficiency of a
transfer. This fact provides an economic rationale for regulation. However, inalien-
ability goes far beyond regulation. Whereas regulations restrict transfers, inalienabil-
ity prohibits them. The efficiency of a transfer cannot increase by prohibiting it. In
general, prohibitions on transfers are inefficient because they prevent people from get-
ting what they want. Following this line of thought, some economic writers have at-
tacked laws that make certain goods inalienable.52 Is there any economic rationale for
inalienability?53

Some theorists argue that the sale of certain commodities undermines their
transfer by superior means. For example, consider the supply of blood to hospitals.
Two complementary means are used to ensure that blood is free from infection: A
medical history is taken from the individuals who supply blood, and the blood is
tested in laboratories. The individual suppliers are more likely to provide an accu-
rate medical history when they give their blood away than when they sell it.

162 C H A P T E R 5 Topics in the Economics of Property Law

Consequently, donated blood is freer from infection. This fact provides an economic
rationale for obtaining blood by donations rather than purchases, but not a reason
for prohibiting the sale of blood.54 For example, in the United States most blood is
obtained by donations, but some blood is purchased.55

However, assume that the sale of blood undermines voluntary donations. For
example, people might feel that giving blood away for free is stupid so long as it can
be sold. If these facts were true, then prohibiting the sale of blood might be neces-
sary in order to divert transfers into the superior channel of gifts. Similarly, anthro-
pologists have argued that markets destroy gift economies among tribal people.
Although plausible, the factual support for this theory is not strong enough to pro-
vide a convincing defense of inalienability. It seems, then, that inalienability rests
on conventional morality and political philosophies that stress values other than
Pareto efficiency.

QUESTION 5.28: Assume that every adult in a particular jurisdiction is eli-
gible to serve as a juror. Panels of potential jurors are drawn by rotation from
the qualified population. Currently, no jurisdiction allows someone called for
jury service to hire a qualified replacement. Would society be better off if peo-
ple were allowed to engage in a market for jurors?

Web Note 5.7

As the technology for making use of transplantable human organs improves,
the demand for those organs has far outstripped the supply available under the
inalienability rules. See our website (and the box on “Inalienable Bodily
Organs”) for a discussion of how a regulated market in human organs might
significantly increase the supply.

D. Unbundling Property Rights
In England, the boundaries of property are often based on enduring natural objects

and countours of the land such as rocks, trees, or hills. In the United States, much of
the land was surveyed and divided into uniform parcels in the countryside and in
towns.56 Standardizing property simplifies comparing one property to another. Easy

54 See RICHARD TITMUSS, THE GIFT RELATIONSHIP: FROM HUMAN BLOOD TO SOCIAL POLICY (1971), in which
the author argues that inalienability is an efficient method of assuring quality control. See also Kenneth
Arrow, Gifts and Exchanges, 1 PHILOSOPHY & PUBLIC AFFAIRS 343 (1972), and Reuben Kessel, Transfused
Blood, Serum Hepatitis, and the Coase Theorem, 17 J. LAW & ECON. 265 (1974).

55 Blood can be purchased in the United States, but the federal Food and Drug Administration requires labels
to distinguish whether the source is a “paid donor” or “volunteer donor.” Note that nonprofit institutions
that collect blood from “volunteer donors” usually sell it to hospitals.

56 A grid for land boundaries (“rectangular survey”) was an innovation that spread in the British Empire dur-
ing the nineteenth century, replacing the demarcation of land boundaries by natural objects such as trees
and rocks (“metes and bounds”).

III. What May Owners Do with Their Property? 163

Inalienable Bodily Organs

Advances in medical technology have sharply increased demand for transplantable bodily
organs.57 Each year in the United States there are almost 80,000 people waiting for organ trans-
plants. But the supply of suitable organs, is much smaller—approximately 10,000
organs per year. Excess demand in a market causes the price to rise, which brings supply and
demand into equilibrium. This cannot happen to transplantable organs because all states
adopted the Uniform Anatomical Gift Act of 1968, which forbids the sale of organs.
Consequently, gifts or donations are the only means by which to supply transplantable bodily
organs. The donor may consent to give up transplantable organs in the event of his or her death.
People often have the opportunity to consent when renewing a driver’s license. However, less
than 20 percent of the United States’ driving-age population has filled out the donor cards.
Absent consent, the current system typically requires physicians to ask next of kin whether they
may “harvest” the organs of the decedent. This is not the best time to make such a request.

To cope with excess demand, the United States has a non-market method of allocating
organs. The rules are very complicated, but most organs are awarded in the order in which
patients have been on an official waiting list. In 2006 the organization overseeing organ
transplantation (UNOS) suggested an alternative rule—organs may be given first to those
likely to live the longest after a transplant. That controversial proposal is still under discussion.

How to increase the supply of organs for transplant? Technology may develop more artificial
organs, or technology may make it increasingly possible to transplant organs from other animals
into humans. Alternatively, a regulated market in human organs might be allowed somewhere in
the world. (The virtues and pitfalls of such a market are explored in the sources that follow.)

However, some nations have already implemented a rule that dramatically increases the
supply of organs. We called the current donation rule “required consent.” While less than
20 percent of the United States’ driving-age population has filled out the donor cards, 85 per-
cent of that same population say that they are willing to make a donation of their organs. An
alternative to required consent is a rule of “presumed consent”: Everyone is presumed to have
consented to his or her organs being harvested upon death unless they have affirmatively de-
clared otherwise. Data suggests that switching from required consent to presumed consent dra-
matically increases the supply of organs. The four European countries with a rule of required
consent (Denmark, Germany, the Netherlands, and the United Kingdom) have much lower rates
of donation (ranging from 4.25 percent in Denmark to 27.5 percent in the Netherlands) than
do the six countries (Austria, Belgium, France, Hungary, Poland, Portugal, and Sweden) that use
a rule of presumed consent (ranging from a low of 85.9 percent to a high of 99 percent).

SOURCES:

See Lloyd R. Cohen, Increasing the Supply of Transplantable Organs: The Virtues of a Futures Market, 58 Geo.
WASH. L. REV. 1 (1989).

Gregory Crespi, Overcoming the Legal Obstacles to the Creation of a Futures Market in Bodily Organs, 55 OHIO ST.
L. J. 1 (1994).

RICHARD EPSTEIN, MORTAL PERIL: OUR INALIENABLE RIGHT TO HEALTH CARE? (1997).

Eric J. Johnson & Daniel Goldstein, “Do Defaults Save Lives?,” 302 SCIENCE 1338 (2003).

57 An economist joke about this situation goes like this: A patient waiting for a heart transplant learns from
his doctor that there are suddenly two hearts available—one from a 24-year-old marathon runner and one
from an elderly economist. Without hesitation the patient chooses to receive the heart of the economist. It
explains to his astonished doctor, “It is unused.”

164 C H A P T E R 5 Topics in the Economics of Property Law

comparison of property opens the real estate market to broader competition because
potential buyers need less information to compare the value of one property relative to
another. Besides real estate, uniformity lubricates sales for stocks, bonds, wheat, oil,
and many other goods.

Conversely, inconsistent bundles of rights make properties incomparable to each
other, so prices must be negotiated individually. Thus, one share of stock issued by
Honda is the same as another share of the same class of stock. Honda shares have a pub-
lic price in the stock market at which they can be bought or sold. In contrast, investment
banks have created bundles of unstandardized real estate mortgages (“derivatives”)
whose prices are individually negotiated. Unlike stock market prices, individually nego-
tiated prices for securities are not public information. Most people do not know the price
at which such a security last sold. When securities prices plummeted in the financial
meltdown of 2008, Harvard University held many unstardardized securities without a
public price, so it did not know how much value its portfolio had lost.

In general, the owners of property possess a bundle of rights. To standardize prop-
erty, the law must restrict the owner’s ability to repackage these rights. The owner of a
good may have rights w, x, y, and z over it. The owner may want to unbundle these
rights and sell w and x to one person, while retaining y and z for himself. Sometimes,
however, law only allows sales of the complete bundle. For example, the owner of a
city lot can sell it as a whole, but city regulations may prevent him from cutting it in
half and selling half of it.