strategies which support cooperation in one group only. These last strategies have the property that cheating on the agreement in … the cooperative group is followed by non-cooperation in this group and cooperation in the rival group. The main conclusion … is that the set of parameters for which cooperation can be sustained within the larger group as a subgame perfect outcome …

This paper studies the evolution of peoplesʼ models of how other people think – their theories of mind. This is …

the partnership entered the cooperation phase. We show that such reference letters can be voluntarily provided by the …

-known result in such setting is that under random matching cooperation vanishes for any interior initial condition. The novelty of … mechanism makes cooperation the unique outcome in the long run. Furthermore, we show that if imitation happens infrequently …

controlling for a subjectʼs past earnings. Punishment strategies are generally softer and more graduated than implied by a grim …

In dealing with peer punishment as a cooperation enforcement device, laboratory studies have typically concentrated on … test for this ‘legitimate punishment’ institution and show that it yields substantial benefits to cooperation and … cooperation rates and earnings. This interaction result implies that providing feedback over virtuous behavior in the group is …

contribution rules related to efficiency, equality, and equity. In the experiment, in the absence of punishment no positive … contribution norm is observed and all groups converge towards free-riding. With punishment, strong and stable differences in …

equilibrium; they serve as punishments should deviations occur. It does not require whether a punishment can be justified for the … punishment is justifiable if either the deviation is bad to the other player or the continuation itself is good to the other …