Collusive agreements are often observed in procurement auctions. They are probablymore easily achieved when competitors’ costs are easily estimated. If, however, the individualcosts of bidders are private information, effective ring formation is difficult to realize.We compare experimentally...

The common prior assumption justifies private beliefs as posterior probabilities when updatinga common prior based on individual information. Common priors are pervasive in most economicmodels of incomplete information and oligopoly models with asymmetrically informed firms. Wedispose of the...

Social institutions regulating group conduct have been regarded as necessaryfor human cooperation to transcend family bonds. However, manystudies in economics and biology indicate that reciprocity based on repeatedinteraction suffices to establish cooperation with non-kin. We shedlight on the...