Evolution in the finitely repeated prisoner’s dilemma
John H. Nachbar
Washington University, St. Louis, MO, USA
This paper examines some aspects of ‘evolutionary’ dynamic behavior in the finitely repeated prisoner’s dilemma. The ‘fitness’ of cooperation found in the best known simulation of this type, that by Robert Axelrod, stems from strategy set restrictions: The game used for the simulation has a continuum of pure cooperation equilibria and no pure defection equilibrium. Some new simulations are presented here for the finitely repeated game. Although cooperation is ultimately exploited and extinguished, dynamic paths can ‘pseudo converge’ in ways that allow partial cooperation to flourish for extended periods of time.