ON THE ESSENTIALITY OF BANKS*
在一个去中心化交易和有限监督的搜索模型中，比较了信贷与银行票据（内部货币）支持的资源配置，发现信贷安排优于内部货币，但贸易扩张而监督不足时信贷不可靠，从而解释了银行在贸易密集且监督有限时的必要性，并用于说明中世纪和近代早期欧洲银行的起源。
We compare allocations sustained by credit with allocations sustained by bank notes (inside money) in a search model with decentralized trade and limited monitoring. We demonstrate that there exists a credit arrangement that is superior to inside money. However, in contrast with inside money, this arrangement is not robust to an expansion of trade that is not accompanied by an adequate increase in the degree of monitoring. Therefore, banks are essential when trade is intense and monitoring is limited. As a historical application, we argue that our model helps explain the origins of banking in Medieval and Early Modern Europe.