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...

Due to incomplete contracts, efficiency of an organization depends on willingness of individuals to take non-selfish actions, such as cooperating when there is no incentive to do so or punishing inefficient actions by others. Organizations also constitute a social boundary, or group. We...