A game theoretic fundation of competitive quilibria with adverse selection
构建了一个允许企业提供任意有限合同集并可退出市场的扩展式博弈,证明子博弈完美均衡总是存在,并指出在微小退出成本下,Miyazaki-Wilson合同是唯一的稳健均衡结果。
We construct an extensive form game that captures competitive markets with adverse selection. It allows firms to offer any finite set of contracts, so that cross-subsidization is not ruled out. Moreover, firms can withdraw from the market after initial contract offers have been observed. We show that a subgame perfect equilibrium always exists. In fact, when withdrawal is costless, the set of equilibrium outcomes may correspond to the entire set of feasible contracts. We then focus on robust equilibria that continue to exist for small withdrawal costs. We show that the Miyazaki–Wilson contracts are the unique robust equilibrium outcome.