SOCIAL-WELFARE, COOPERATORS ADVANTAGE, AND THE OPTION OF NOT PLAYING THE GAME

We outline a model of how freedom to choose between playing and not playing particular Prisoner's Dilemma games can (1) increase social welfare and (2) provide relative gains to intending cooperators. When cooperators are relatively more willing to play, they will interact more frequently with each other and their payoff per encounter will be higher-potentially higher than that of intending defectors. Because the cooperate-cooperate outcome produces more wealth than any other, optional entry will increase social welfare. We report laboratory data showing: (1) Social welfare and the relative welfare of intending cooperators are higher when subjects are free to choose between entering and not entering particular Prisoner's Dilemma relationships; and (2) this difference is a consequence of intending cooperators' greater willingness to enter such relationships, not because of any capacity to recognize and avoid intending defectors. We speculate about the cognitive processes that underlie this result.