We evaluate the stability of risk-sharing contracts in the presence of moral hazard. Contracts are rules for sharing output among producers and affect the extent of private investments in production. Organizations, which are identified with the contracts they offer, compete for membership....

In a number of evolutionary models the presence of mutations, or random components of choice, serve to refine predictions of long-run behavior. We analyze the effects of mutation rates that vary because of the presence of imitation. A full characterization of long-run outcomes is provided for...