Two players choose whether to cooperate on a project. Each of them is endowed with some evidence, and if both possess a sufficient amount then cooperation is profitable. In order to facilitate cooperation the players reveal evidence to one another. However, some players are concerned about...

We investigate the scope for cooperation within a community engaged in repeated reciprocal interactions. Players seek the help of others and approach them sequentially according to some fixed order, that is, a ranking profile. We study the ranking profiles that are most effective in sustaining...