Exerting Control in Repeated Social Dilemmas with Thresholds

TL;DR

This paper explores how threshold nonlinearities influence the ability of players to exert unilateral control in finitely repeated public goods and snowdrift games, revealing conditions that limit or enable various zero-determinant strategies.

Contribution

It identifies conditions under which cooperator thresholds affect the existence and nature of zero-determinant strategies in social dilemma games.

Findings

Thresholds prevent equalizing ZD strategies in both games.

In snowdrift games, thresholds do not affect extortionate ZD strategies.

Thresholds restrict enforceable extortionate strategies in public goods games for small multipliers.

Abstract

Situations in which immediate self-interest and long-term collective interest conflict often require some form of influence to prevent them from leading to undesirable or unsustainable outcomes. Next to sanctioning, social influence and social structure, it is possible that strategic solutions can exist for these social dilemmas. However, the existence of strategies that enable a player to exert control in the long-run outcomes can be difficult to show and different situations allow for different levels of strategic influence. Here, we investigate the effect of threshold nonlinearities on the possibilities of exerting unilateral control in finitely repeated n-player public goods games and snowdrift games. These models can describe situations in which a collective effort is necessary in order for a benefit to be created. We identify conditions in terms of a cooperator threshold for the existence of generous, extortionate and equalizing zero-determinant (ZD) strategies. Our results show that, for both games, the thresholds prevent equalizing ZD strategies from existing. In the snowdrift game, introducing a cooperator threshold has no effect on the region of feasible extortionate ZD strategies. For extortionate strategies in the public goods game, the threshold only restricts the region of enforceable strategies for small values of the public goods multiplier. Generous ZD strategies exist for both games, but introducing a cooperator threshold forces the slope more towards the value of a fair strategy, where the player has approximately the same payoff as the average payoff of his opponents.