> How can cooperation remain stable when people have unequal wealth? It depends on your explanation for why cooperation can evolve at all. What makes cooperatio

> How can cooperation remain stable when people have unequal wealth? It depends on your explanation for why cooperation can evolve at all. What makes cooperation work, in our paper, is direct reciprocity, which means that we play repeatedly. I can hurt you next round if you hurt me this round, even if you are slightly more wealthy than I am. And, depending on how much I can hurt you next round, this might still be enough to make you cooperate in the present round. It sounds like you want to cooperate just enough to avoid violence but as little as possible to maximize your wealth. Seems pretty on par with history.