Making participation voluntary may discourage cheating
To get people to cooperate in a venture, make participation voluntary. That's the advice from researchers whose recent study offers a solution to one of the oldest problems in game theory: How can cooperation develop if individuals can do better for themselves by cheating?
In a community garden, for example, the lazy gardener who does nothing may reap as big a share of the produce as the hardest worker.
Such antisocial behavior is reduced if cheaters face consequences. An industrious gardener may deny the slacker his share of the harvest, for example. But that raises another issue. Gardeners who pitch in but don't punish freeloaders may get just as much produce as those who punish, without the risk and trouble of punishing someone.
Short-term self-interest seems to encourage an individual either to cheat or to cooperate but not to punish. In the long run, however, everyone is better off if most people both cooperate and punish. Then cheaters don't profit, the burd