We examine a “Rotten Kid” model (Becker 1974) where a player with social preferences interacts with an egoistic player. We assume that social preferences are intentionbased rather than outcome-based. In a very general multi-stage setting we show that any equilibrium must involve mutually...

The paper shows that, in some important respects, the differences between the Nash equilibrium and competing concepts such as the quantalresponse equilibrium are smaller than they appear. I start from the observation that, in many experiments, parameter shifts that leave the Nash equilibrium...

Are initial competitive advantages self-reinforcing, so that markets exhibit an endogenous tendency to be dominated by only a few firms? Although this question is of great economic importance, no systematic empirical study has yet addressed it. Therefore, we examine experimentally whether firms...