Evolutionary Games and Equilibrium Selection.

• Author: Mezzetti, Claudio

By Larry Samuelson.

Cambridge, MA: The MIT Press, 1997. Pp. ix, 309. $40.00.

This book is an overview of the recent economics literature on evolutionary games with a special emphasis on Larry Samuelson's own, wide-ranging research. Although most of the results have already appeared in journal articles, they are here put together and elaborated upon in a very convincing and coherent way. In fact, one of the nicest features of this book is that it gives us a clear picture of the underlying motivation and views of a leading researcher on evolutionary game theory. The book should be of great interest to anyone interested in this area and, more in general, game theory.

The evolutionary approach to games has been one of the hot topics of the 1990s in economic theory. Stemming from the application of noncooperative game theory to biology, evolutionary game theory postulates that players (e.g., genes or animals) are programmed to play a given strategy. Under the assumption that strategies yielding higher payoffs reproduce faster (payoffs measure reproductive fitness), biologists have studied the evolution of populations of players over time. In particular, they have focused on the study of strategies that are stable in the sense of surviving in the long run. Interestingly, only strategies corresponding to a Nash equilibrium, the fundamental concept of noncooperative game theory, have been found to be evolutionarily stable. However, not all Nash equilibria are evolutionarily stable.

By replacing the assumption of faster biological reproduction of the fittest with adaptation by players towards strategies yielding higher payoffs, economists have looked at evolutionary game theory as providing a framework for modelling boundedly rational behavior. Two main questions have attracted much attention. First, to what extent do evolutionary models yield outcomes in which agents appear to act rationally? Second, to what extent do evolutionary models help in selecting among Nash equilibria? Providing answers to these two questions is the main running theme of this book.

The first three chapters lay the foundations upon which the book is built. Chapter 1 is a very well-written introduction in which Samuelson explains his research philosophy and general views on game theory. Chapter 2 contains a brief survey of the evolutionary approach to games. The notion of an evolutionarily stable strategy (and some of its variants) is introduced first, and its relationship...