Standard prisoners' dilemma games offer players the binary choice between cooperating and defecting, but in a related game there is the third possibility of leaving the game altogether. We conceptualize exiting as taking the individual beyond the reach of externalities generated in the original group, and on that basis—together with the assumption of self-interested (dollar-maximizing) behavior on the part of all players—we derive the prediction that the exit option will drain the community or group more of cooperators than of defectors.But experimental data do not support this prediction; cooperators do not leave more frequently than defectors and, in fact, there is evidence that defectors are more prone to leave than cooperators. We consider and reject the possibility that this failure of prediction results from the (admitted) greater optimism of cooperators about the incidence of cooperation "here," and present data supporting the hypothesis that cooperators often stay when their personal interest is with exiting because of the same ethical or group-regarding impulse that (presumably) led them to cooperate in the first place. Cooperation can be produced for a group or community either by inducing people to cooperate or by inducing those who are going to cooperate to stay in the game, and ethical considerations seem to underlie the decision to stay as well as the decision to cooperate while staying.
Theoretical work on parliamentary government leads to the expectation that parties will defect from governing coalitions when they anticipate greater payoffs in replacement governments or after new elections; similarly, governments as a whole (or their prime ministers) will dissolve legislatures prematurely with the same expectation in mind. Surprisingly, however, very little empirical work has been done to assess the extent to which defectors from or dissolvers of coalition governments actually manage to profit from their actions. We also know very little about what happens to coalition members who engage in government-ending disputes. The purpose of this paper is to address these deficiencies by examining the fates of dissolvers, defectors, and disputers in West European democratic systems since 1945. The results show that parties generally end up no better off, and usually worse off, in terms of measurable benefits when they engage in these types of action.