Economic theory predicts that it is impossible to have cooperation in finitely repeated games such as a prisoners' dilemma game without communication. Yet experimental results follow a contradicting pattern : for example, cooperation is generally observed in public-goods experiments, at least in...

Economic theory predicts that it is impossible to have cooperation in finitely repeated games such as a prisoner's dilemma game without communication. In an experiment on a voluntary participation game with a non-excludable public good that is a version of a Hawk-Dove game, we obderved that...