In this paper, we introduce a perfect competition test which checks the incentives of arbitrarily small coalitions to behave strategically in endowments and preferences. We apply this coalitional incentive compatibility test to atomless economies with a continuum of differentiated commodities....

We introduce a two-period economy with asymmetric information about the state of nature that occurs in the second period. Each agent is endowed with an information structure that describes her (incomplete) ability to prove whether or not a state has occurred. We show that if the number of states...