Many experimental studies indicate that people are motivated by reciprocity. Rabin (1993) develops techniques for … reciprocity for extensive games in which the sequential structure of a strategic situation is made explicit. We propose a new … solution concept— sequential reciprocity equilibrium—which is applicable to extensive games, and we prove a general equilibrium …

indicates that this is indeed likely to be the case. But reciprocity or gift-exchange induces social relations. The utility …

equilibrium.We find that there is significantly more cooperation when actions exhibit strategic complementarities than in case of …