This paper experimentally investigates the effects of a costly punishment option on cooperation and social welfare in long, finitely repeated public good contribution games. In a perfect monitoring environment, increasing the severity of the potential punishment monotonically increases average...

We develop a model in which connections between individuals serve as social collateral to enforce informal insurance payments. We show that: (i) The degree of insurance is governed by the expansiveness of the network, measured with the per capita number of connections that groups have with the...