A social dilemma is a game which at first glance has only inefficient solutions. If efficient solutions are to be achieved, some kind of cooperation among the players is required. This book asks two basic questions, closely intertwined with each other: 1. How is cooperation possible among rational players in such a social dilemma? Which changes in the social context of a social dilemma situation are necessary in order for players to rationally choose the cooperative option? 2. How do real players actually behave in social dilemma situations? Do they behave "rationally" at all? Or, conversely, what kind of reasoning, attitudes, emotions, etc. shape the behavior of real players in social dilemmas? What kind of interventions, what kind of internal mechanisms within a real group may change players' willingness to cooperate? These two general questions mark the broad spectrum of the problem which has been, over the last three decades, investigated in various disciplines, and which has brought many new ideas and new observations into the study of the old question of social order in a world of born egoists. Accordingly, this volume contains contributions by biologists, sociologists, political scientists, economists, mathematicians, psychologists, and philosophers.

There are two main approaches towards the phenotypic analysis of frequency dependent natural selection. First, there is the approach of evolutionary game theory, which was introduced in 1973 by John Maynard Smith and George R. Price. In this theory, the dynamical process of natural selection is not modeled explicitly. Instead, the selective forces acting within a population are represented by a fitness function, which is then analysed according to the concept of an evolutionarily stable strategy or ESS. Later on, the static approach of evolutionary game theory has been complemented by a dynamic stability analysis of the replicator equations. Introduced by Peter D. Taylor and Leo B. Jonker in 1978, these equations specify a class of dynamical systems, which provide a simple dynamic description of a selection process. Usually, the investigation of the replicator dynamics centers around a stability analysis of their stationary solutions. Although evolutionary stability and dynamic stability both intend to characterize the long-term outcome of frequency dependent selection, these concepts differ considerably in the 'philosophies' on which they are based. It is therefore not too surprising that they often lead to quite different evolutionary predictions (see, e. g. , Weissing 1983). The present paper intends to illustrate the incongruities between the two approaches towards a phenotypic theory of natural selection. A detailed game theoretical and dynamical analysis is given for a generic class of evolutionary normal form games.

The four volumes of Game Equilibrium Models present applications of non-cooperative game theory. Problems of strategic interaction arising in biology, economics, political science and the social sciences in general are treated in 42 papers on a wide variety of subjects. Internationally known authors with backgrounds in various disciplines have contributed original research. The reader finds innovative modelling combined with advanced methods of analysis. The four volumes are the outcome of a research year at the Center for Interdisciplinary Studies of the University of Bielefeld. The close interaction of an international interdisciplinary group of researchers has produced an unusual collection of remarkable results of great interes for everybody who wants to be informed on the scope, potential, and future direction of work in applied game theory. Volume I Evolution and Game Dynamics mainly deals with dynamic stability with respect to evolutionary processes. The book offers not only theoretical classification of the foundations of evolutionary game theory, but also exciting new biological applications. Volume II Methods, Morals and Markets contains areas of research which will attract the interest of economists, political scientists, mathematicians and philosophers. The papers deal with the methodology of analysis of games, game theoretic contributions to fundamental ethical questions facing societies and game-theoretic analyses of market environments. Volume III Strategic Bargaining contains ten papers on game equilibrium models of bargaining. All these contributions look at bargaining situations as non-cooperative games. General models of two-person and n-person bargaining areexplored. Volume IV Social and Political Interaction contains game equilibrium models focussing on social and political interaction within communities or states or between states, i.e. national and international social and political interaction. Specific aspects of those interactions are modelled as non-cooperative games and their equilibria are analysed.