Voluntary Cooperation Based on Equilibrium Retribution – An Experiment Testing Finite-Horizon Folk Theorems Volume 3 Jena Economic Research Papers 2009-04-21 2009 2007 2009-030 Folk theorem Finite horizon Prisoners’ dilemma Experiment 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 experimental treatments distinguish long versus short horizon and strict versus non-strict additional equilibrium compared to the control treatment, a standard prisoners’ dilemma. Quite surprisingly, according to our results, only a strict additional equilibrium increases cooperation rate for a given time horizon. As expected a longer time horizon promotes cooperation. jportal_jpjournal_00000016 2009-04-21T12:36:14.232Z 2010-12-17T11:54:00.112Z