This paper presents a new reason why countries may want to keep separate currencies rather than form a currency union. In a search model of a two-country world, keeping multiple currencies with trade restrictions that favor the use of the domestic currency in domestic goods markets is socially beneficial relative to forming a currency union or letting multiple currencies circulate in all countries without restrictions. Multiple currencies improve the allocation of liquidity in the presence of trading frictions that make the use of currencies necessary to exchange commodities.

中文翻译：

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多种货币的社会效益

本文提出了一个新的原因，为什么各国可能希望保持单独的货币而不是形成货币联盟。在两国世界的搜索模型中，相对于形成货币联盟或让多种货币在所有国家不受限制地流通，保持多种货币有利于在国内商品市场上使用本国货币的贸易限制在社会上是有益的。在存在交易摩擦的情况下，多种货币改善了流动性的分配，这使得必须使用货币来交换商品。