We test an assortative mechanism whereby groups are formed endogenously, through the use of voting. Once formed, groups play a public-goods game, where the social value of an incremental contribution to the group account increases with the size of the group. Societies of nine people are...

We test a mechanism whereby groups are formed voluntarily, through the use of voting. These groups play a public-goods game, where efficiency increases with group size (up to a limit, in one treatment). It is feasible to exclude group members, to exit one's group, or to form larger groups...

We perform an experimental test of Maskin's canonical mechanism for Nash implementation, using 3 subjects in non-repeated groups, as well as 3 outcomes, states of nature, and integer choices. We find that this mechanism succesfully implements the desired outcome a large majority of the time and...

Costless and non-binding pre-play communication (cheap talk) has been found to often be effective in achieving efficient outcomes in experimental games. However, in previous two-player experimental games each player was informed about both his payoff and the action of the other player in the...

The effectiveness of pre-play communication in achieving efficient outcomes has long been a subject of controversy. In some environments, cheap talk may help to achieve coordination. However, Aumann conjectures that, in a variant of the Stag Hunt game, a signal for efficient play is not...

We study experimentally a two-stage compensation mechanism for promoting cooperation in prisoner's dilemma games. In stage 1, players simultaneously choose binding non-negative amounts to pay their counterparts for cooperating in a given prisoner's dilemma game, and then play the prisoner's...