A large population plays a two-period sequential common agency game. Agents are long lived, while principals are short lived. Preferences and technology are additively separable in time and time independent. At the onset, agents are matched in pairs under private information of individual types....

The paper studies, in a repeated interaction setting, how the presence of cooperative agents in a heterogeneous community organized in groups, affects group efficiency and stability. The paper extends the literature by assuming that each type can profitably mimic other types. It is shown that...