Zero-Determinant Strategies in Repeated Multiplayer Social Dilemmas With Discounted Payoffs

Abstract

In two-player repeated games, zero-determinant (ZD) strategies enable a player to unilaterally enforce a linear payoff relation between her own and her opponent's payoff irrespective of the opponent's strategy. This manipulative nature of the ZD strategies attracted significant attention from researchers due to their close connection to controlling distributively the outcome of evolutionary games in large populations. In this article, necessary and sufficient conditions are derived for a payoff relation to be enforceable in multiplayer social dilemmas with a finite expected number of rounds that is determined by a fixed and common discount factor. Thresholds exist for such a discount factor above which desired payoff relations can be enforced. Our results show that depending on the group size and the ZD strategist's initial probability to cooperate their existing extortionate, generous, and equalizer ZD strategies. The threshold discount factors rely on the desired payoff relation and the variation in the single-round payoffs. To show the utility of our results, we apply them to multiplayer social dilemmas, and show how discounting affects ZD Nash equilibria.