We study infinitely repeated anonymous random matching games played by communities of players, who only observe the outcomes of their own matches. It is well known that cooperation can be sustained in equilibrium for the prisoner's dilemma (PD) through grim trigger strategies. Little is known...

We study impersonal exchange, and ask how agents can behave honestly in anonymous transactions without contracts. We analyze repeated anonymous random matching games, where agents observe only their own transactions. Little is known about cooperation in this setting beyond the prisoner's...

A fundamental question in social sciences is how trust emerges. We provide an answer which relies on the formation of social and economic relationships. We argue that behind trust lies the fact that individuals invest in connections taking into account the potential externalities networks...