We study conflict between two groups of individuals. Using Schaffer's (1988) concept of evolutionary stability we provide an evolutionary underpinning for in-group altruism combined with spiteful behavior towards members of the rival out-group. We characterize the set of evolutionarily stable...

A leading solution concept in the evolutionary study of extensive-form games is Selten (1983) notion of limit ESS. This note demonstrates that a limit ESS does not imply neutral stability, and that it may be dynamically unstable (almost any small perturbation takes the population away). These...

We demonstrate that in simple 2×2 games (cumulative) prospect theory preferences can be (semi-)evolutionarily stable, in particular, a population of players with prospect theory preferences is stable against more rational players, i.e. players with a smaller degree of probability weighting. We...

What preferences will prevail in a society of rational individuals when preference evolution is driven by their success in terms of resulting payoffs? We show that when individuals’ preferences are their private information, a convex combinations of selfishness and morality stand out as...

We provide a generalized definition of evolutionary stability of heritable types in arbitrarily large symmetric interactions under random matching that may be assortative. We establish stability results when these types are strategies in games, and when they are preferences or moral values in...

The paradoxical full-surplus-extraction (FE) result, which can impair the mechanism design paradigm, is a long-standing concern in the literature. We tackle this problem by experimentally testing the performance of an FE auction, which is a second-price (2P) auction with lotteries. In the FE...

Indirect reciprocity describes a class of reputation-based mechanisms which may explain the prevalence of cooperation in groups where partners meet only once. The first model for which this has analytically been shown was the binary image scoring mechanism, where one's reputation is only based...

Suppose that in aggregative games, in which a player's payoff depends only on this player's strategy and on an aggregate of all players' strategies, the players are endowed with constant conjectures about the reaction of the aggregate to marginal changes in the player's strategy. The players...

We adopt an evolutionary approach to investigate whether and when conditional cooperation can explain the voluntary contribution phenomenon often observed in public goods experiments and real life. Formally, conditional cooperation is captured by a regret parameter describing how much an...