We provide an example where establishing competitive coordination service platforms is so lucrative that they end up reducing welfare. We consider a canonical directed search model in which buyers have unit demands and sellers' capacity constraint leads to a coordination problem: in a symmetric equilibrium without intermediation some sellers receive too many and some too few buyers. We compare this equilibrium to one where sellers and buyers can choose to become intermediaries who coordinate the meetings. In this setup, roughly one‐fifth of agents become intermediaries. As a result, a large part of the supply and demand in the economy vanishes. Moreover, the large amount of intermediaries actually reduces the meeting efficiency. Jointly, these effects imply that the gains from trade are lower than that in the economy without intermediation.

中文翻译：

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定向搜索模型中的中介

我们提供了一个示例，其中建立竞争性协调服务平台非常有利可图，以至最终导致减少福利。我们考虑一种规范的定向搜索模型，其中买方具有单位需求，卖方的能力约束导致协调问题：在没有中介的对称均衡中，一些卖方收到太多或更少的买方。我们将这种均衡与买卖双方可以选择成为协调会议的中介机构进行比较。在这种设置中，大约五分之一的代理成为中介。结果，经济中的很大一部分供求关系消失了。而且，大量的中介实际上降低了会议效率。这些影响共同表明，贸易收益要比没有中介的经济收益要低。