Setting an example: The effect of unequal endowments on cooperation in sequential public goods games

Combating global crises like climate change requires large-scale cooperation among actors with different amounts of resources. The present investigation examines how signals of cooperativeness from a first-mover influence subsequent cooperation depending on the resources of the first-mover and the followers. In two studies, participants (total N = 1325) took part in a sequential public goods game with one first-mover and four followers. First-movers and followers were either privileged (i.e., endowed with high resources) or underprivileged (i.e., endowed with low resources). Participants decided how much to contribute to the public good given the first-mover cooperated fully, cooperated partially, or defected. Overall, higher first-mover cooperation fostered higher follower cooperation. More importantly, follower cooperation depended on first-movers’ and followers’ resources: Follower cooperation was higher when privileged first-movers cooperated fully compared to when underprivileged first-movers cooperated fully, pointing to an effect of absolute contribution. However, follower cooperation was also higher when underprivileged first-movers cooperated fully compared to when privileged first-movers contributed the same amount as part of their endowment, pointing to an effect of relative contribution. In Study 1, we found an interaction between first-movers’ and followers’ endowments when first-movers cooperated fully: When the first-mover was underprivileged, privileged followers contributed a significantly smaller share of their resources than underprivileged followers. This effect was smaller when first-movers were privileged. Given the first-mover defected, follower contributions did not significantly depend on first-movers’ or followers’ resources. Overall, the findings imply that cooperative signals from privileged actors are particularly effective but cooperative first-movers may foster subsequent cooperation no matter their resources.