Unlike previous attempts to implement cooperation in a prisoners' dilemma game with an infinite horizon in the laboratory, we focus on extended prisoners' dilemma games in which a second (pure strategy) equilibrium allows for voluntary cooperation in all but the last round. Our four main...

Using a symmetric 2-person prisoners' dilemma as the base game, each player receives a signal for the number of rounds to be played with the same partner. The actual number of rounds (the length of the supergame) is determined by the maximal signal where each player expects the other's signal to...