This paper studies the existence of equilibrium solution concepts in a large class of economic models with discontinuous payoff functions. The issue is well understood for Nash equilibria, thanks to Reny’s better-reply security con- dition ( Reny 1999) and its recent improvements (Barelli and...

We consider the set-up of a Japanese-English auction with exogenously fixed discrete bid levels for the wallet game with two bidders. We prove that bidding twice the signal - the equilibrium strategy with continuous bid levels - is never an equilibrium in this set up. We show that partition...

The paper studies when efficient allocations are implementable via coalition-proof mechanisms. When ambiguous mechanisms are allowed and agents are maxmin expected utility maximizers, we prove that all efficient allocations are implementable via interim coalition incentive compatible mechanisms...