The infinitely repeated prisoners' dilemma has a multiplicity of Pareto-unranked equilibria. This leads to a battle of the sexes problem of coordinating on a single efficient outcome. One natural method of achieving coordination is for the players to bargain over the set of possible equilibrium...

We consider the problem of a principle who wishes to induce two agents playing a one shot prisoner's dilemma to behave cooperatively. We assume that the principal cannot observe the actions of the agents, and is not able to change the strategy sets or payoff functions in the underlying game. The...