This article aims to clarify the analogy between contingent claims in a complete market and banking contracts in a capitalized financial intermediary that combines both deposit and equity. It brings together insurance theory and financial intermediation theory in a synthetic model by focusing on the risk allocation function rather than on a particular kind of institutional arrangement. The model includes both idiosyncratic liquidity risk and aggregate uncertainty on asset return, and it focuses on risk allocation in a perfect information setting from an insurance perspective. This article then highlights that equity contracts are equivalent to state-contingent claims in the aggregate-risk shifting, that deposit contracts are equivalent to type-contingent claims in the idiosyncratic-risk mutualization, and that banks and markets both implement the optimal allocation by simply using different mechanisms.

本文旨在阐明完整市场中的或有债权与结合了存款和股权的资本化金融中介中的银行合同之间的类比。它将保险理论和金融中介理论结合在一个综合模型中，重点关注风险分配函数而不是特定类型的制度安排。该模型既考虑了异质流动性风险，又考虑了资产回报的总体不确定性，从保险角度关注完美信息环境下的风险分配。然后本文强调，股权合约相当于总风险转移中的状态或有债权，存款合约相当于异质风险共同化中的类型或有债权，