Competitive Equilibria and the Core of Exchange Economies under Asymmetric Information

I argue in favor of a competitive screening approach for studying the question of coalition formation in exchange economies under asymmetric information. I obtain a new notion of core that refines Wilson (1978)'s coarse core. It is nonempty under the standard regularity conditions. I also justify a notion of competitive equilibrium formerly introduced by Wilson as a technical tool for proving the nonemptiness of the coarse core. Indeed, the core converges to the set of Wilson equilibria when the economy is replicated