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)...

We study centipede games played by an infinite sequence of players. Following the literature on time-inconsistent preferences, we distinguish two types of decision makers, naive and sophisticated, and the corresponding solution concepts, naïve ϵ-equilibrium and sophisticated ϵ-equilibrium. We...

In human societies, overcoming incentives to act selfishly is immensely important so as to promote prosocial behaviours. Social norms and relational utility, utility generated by such feelings as guilt, are mechanisms by which cooperation and coordination can be facilitated. Here we add...

A budget-constrained buyer wants to purchase items from a shortlisted set. Items are differentiated by observable quality and sellers have private reserve prices for their items. The buyer's problem is to select a subset of maximal quality. Money does not enter the buyer's objective function,...

A budget-constrained buyer wants to purchase items from a short-listed set. Items are differentiated by observable quality and sellers have private reserve prices for their items. The buyer's problem is to select a subset of maximal quality. Money does not enter the buyer's objective function,...

This paper explores the private and social benefits from barter exchange in a monetized economy. We first prove a no-trade theorem regarding the ability of firms with double-coincidences-of-wants to negotiate improvements in trade among themselves relative to the market outcomes. We then...