We consider a general framework of optimal mechanism design under adverse selection and ambiguity about the type distribution of agents. We prove the existence of optimal mechanisms under minimal assumptions on the contract space and prove that centralized contracting implemented via mechanisms is equivalent to delegated contracting implemented via a contract menu under these assumptions. Our abstract existence results are applied to a series of applications that include models of optimal risk sharing and of optimal portfolio delegation.

中文翻译：

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一般合同空间中的稳健合同

我们考虑了逆向选择和关于代理类型分布的歧义下的最佳机制设计的一般框架。我们在合同空间的最小假设下证明了最优机制的存在，并证明了在这些假设下，通过机制实施的集中式合同等同于通过合同菜单实施的委托式合同。我们的抽象存在结果被应用于一系列应用程序，其中包括最佳风险分担模型和最佳投资组合委派模型。