We analyze efficient risk-sharing arrangements when coalitions may deviate. Coalitions form to insure against idiosyncratic income risk. Self-enforcing contracts for both the original coalition and any deviating coalition rely on a belief in future cooperation which we term \social capital". We...

We analyze efficient risk-sharing arrangements when the value from deviating is determined endogenously by another risk sharing arrangement. Coalitions form to insure against idiosyncratic income risk. Self-enforcing contracts for both the original coalition and any coalition formed (joined)...

Working hard is costly, so people should work wisely. Yet, they do not always work efficiently, spending their effort on tasks that do not bring tangible benefits. One reason that potentially amplifies inefficient working is that people work in social environments where they are observed and...