Description: Job Market Practice Talk: Kyubin Yim (Iowa State University)
Location: 368A Heady Hall
Title: The effect of networks on cooperation in the finitely repeated prisoner’s dilemma
I discuss the effect of networks on cooperation in the finitely repeated prisoner’s dilemma using three approaches: the game-theoretical model approach, the belief-based learning model approach, and the experimental approach. (1) The game-theoretical model consists of two games: the simple repeated PD (prisoner’s dilemma) game for finite rounds and the repeated PD game on a network after the simple repeated PD game. In the repeated PD game on a network, players choose their game partners who can be neighbors on a network based on mutual consent. I find the subgame perfect pairwise-Nash equilibria in which all players defect and are completely connected or isolated. (2) The belief-based learning model allows updating players’ strategies by learning opponents’ strategies so that it explains the cooperative actions not explained by the game-theoretical model but observed in the experiments. My learning model shows that the strategies based on excluding defectors in network formation drive cooperation. (3) I examine the effect of networks on cooperative actions in human groups in the finitely repeated PD using three game experiments: the simple repeated game, the cheap talk repeated game, and the networked repeated game. First, the average cooperation rate in the networked repeated game is the highest among the three games. Second, the network formation in the networked repeated game is associated with increased cooperation. Finally, cooperators (defectors) are connected with other cooperators (defectors) in the network, and cooperation can be achieved by connections among cooperators who exclude defectors from the network.
Keywords: evolution of cooperation, the network repeated prisoner’s dilemma game, excluding defectors in network formation