An alternative mechanism through which economic inequality facilitates collective action: Wealth disparities as a sign of cooperativeness

Past models treat economic inequality as an exogenous condition that can provide individuals a dominant incentive to produce collective goods unilaterally. Here we part with that tradition so as to treat economic inequality and collective action as endogenous, and to examine whether economic inequality can foster collective action even when all individuals can gain from free-riding. Using evolutionary game theory and computer simulations, we study whether cooperation can evolve when agents play multiple, one-shot prisoner’s dilemma (PD) games per generation and employ strategies that condition cooperative play on their game partners’ wealth holdings. In this game environment, we find that collective action succeeds via a strategy in which players choose to cooperate when joining a PD with an economic equal and defect when partnered with a player possessing wealth holdings unequal to their own. These results signal an alternative avenue through which economic inequality can influence the viability of collective action.