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 pl aying particular Prisoner's Dilemma games can (1) increase social welf are and (2) provide relative gains to intending cooperators. When coop erators are relatively more willing to play, they will interact more f requently with each other and their payoff per encounter will be highe r-potentially higher than that of intending defectors. Because the coo perate-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 dif ference 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 proce sses that underlie this result.