Kenneth George Binmore - Game Theory and the Social Contract, Vol. 2: Just Playing (Economic Learning and Social Evolution)

1998 Massachussetts Institute of Technology

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This book was set in Computer Modern by Ken Binmore. Printed and bound in the United States of America.

Library of Congress Cataloging-in-Publication Data

Binmore, K. G., 1940
Just playing: game theory and the social contract II / Ken Binmore.
v. cm.
Includes bibliographical references and index.
ISBN 0-262-02444-6
1. Game theory. 2. Social contract. 3. Political science
-Philosophy. I. Title.
HB144.B56 199493-29610
519.3dc20CIP

"I couldn't afford to learn it," said the Mock Turtle with a sigh. "I only took the regular course."
"What was that?" inquired Alice.
"Reeling and writhing, of course, to begin with,'' the Mock Turtle replied; "and then the different branches of ArithmeticsAmbition, Distraction, Uglification and Derision.''
Lewis Carroll's Alice in Wonderland

Playing Fair, the first volume of Game Theory and the Social Contract, began with with an old-fashioned apology in which I apologized for many things: for being an outsider in moral and political philosophy; for being simultaneously frivolous and long-winded; for being too mathematical and for not being mathematical enough; and for much else besides. I have nothing new to apologize for in this second volume except perhaps for having taken so long to write it, and for having misjudged the length of the chapters to which I had committed myself. However, under the pretence of apologizing again for some of my old failings, I plan to take the opportunity of responding to some of the methodological criticism that the first volume provoked.

A legend circulates in the economics profession telling of a referee who rejected a paper on the grounds that its results were wrong. The author responded with a definitive refutation of the referee's counterexample, but the referee rejected the paper againthis time on the grounds that the results were correct, but trivial. Such a referee would have a field day with this book, since he could justly argue that it is simultaneously both wrong and trivial.

The book is wrong as a description of the way society works because the stripped-down models it employs are far too simple to come close to capturing the richness and diversity of the full range of human experience. But who ever got anywhere by trying to study the world-as-it-is in all its complexity? To make progress, one has no alternative but to suppress all

but the factors that seem to matter most. The model that results will be wrong to the extent that it is not a full representation of reality. But it is not very interesting to make the obvious point that the world is more complex than the models we use to study it. The interesting question is whether simple models can be found that are enough like the world to make their analysis relevant to real problems. If not, then the prospect for saying anything worthwhile at all is very bleakfor nobody ever manages to solve difficult problems without learning to solve simpler problems first.

In spite of occasional episodes of mathematical huffing and puffing, the book is trivial because the conclusions follow more or less immediately from the assumptions. If my warnings about what was to come were insufficiently emphatic, those who began the first volume hoping to be entertained by deep theorems or cunning arguments therefore genuinely deserve an apology. However, at this stage of its development, it seems to me that political philosophy needs deep theorems and cunning arguments like it needs a hole in the head. What is missing is a comprehensive and systematic framework that is broadly consistent with modern discoveries about human evolutionary history, so that we can keep our feet firmly on the ground while debating ethical problems.