Voting sustains intergenerational cooperation, even when the tipping point threshold is ambiguous

This is the author accepted manuscriptSustaining future generations requires cooperation today. While individuals’ selfish interests threaten to undermine cooperation, social institutions can foster cooperation in intergenerational situations without ambiguity. However, in numerous settings, from climate change to the biodiversity crisis, there exists considerable ambiguity in the degree of cooperation required. Such ambiguity limits the extent to which people typically cooperate. We present the results of an intergenerational public goods game, which show that a democratic institution can promote cooperation, even in the face of ambiguity. While ambiguity in previous work has proved a challenge to cooperation, we find sometimes only small and non-significant effects of ambiguity; more importantly, however, voting is consistently able to maintain sustainable group-level outcomes in both certain and ambiguous settings. Additional analyses demonstrate that this form of democracy has an effect over and above the impact on beliefs alone, and over and above the structural effects of the voting institution. Our results provide evidence that social institutions,such as democracy, can buffer against selfishness and sustain cooperation to provide time-delayed benefits to the future