In this paper we take up a model of Okada (1996) to describe the possibility of collective cooperation in a n …

norms. In recent years, there has been substantial progress, however, on how cooperation norms are enforced. Here we review … insights into the proximate and ultimate forces behind human cooperation. …

outcomes, (ii) laws governing cooperation and collective action, (iii) effects and the determinants of material incentives, (iv …