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Replicator Dynamics for Optional Public Good Games

✍ Scribed by CHRISTOPH HAUERT; SILVIA DE MONTE; JOSEF HOFBAUER; KARL SIGMUND


Publisher
Elsevier Science
Year
2002
Tongue
English
Weight
165 KB
Volume
218
Category
Article
ISSN
0022-5193

No coin nor oath required. For personal study only.

✦ Synopsis


The public goods game represents a straightforward generalization of the prisoner's dilemma to an arbitrary number of players. Since the dominant strategy is to defect, both classical and evolutionary game theory predict the asocial outcome that no player contributes to the public goods. In contrast to the compulsory public goods game, optional participation provides a natural way to avoid deadlocks in the state of mutual defection. The three resulting strategies--collaboration or defection in the public goods game, as well as not joining at all--are studied by means of a replicator dynamics, which can be completely analysed in spite of the fact that the payoff terms are nonlinear. If cooperation is valuable enough, the dynamics exhibits a rock-scissors-paper type of cycling between the three strategies, leading to sizeable average levels of cooperation in the population. Thus, voluntary participation makes cooperation feasible. But for each strategy, the average payoff value remains equal to the earnings of those not participating in the public goods game.