为什么中间商存在?本文提出这一问题。依托西方经济史文献,解释中间商的功能及经济性质,指出这些文献在解释中间商的出现与经济变迁上存在的不足,进而说明需要一种解释经济组织变迁的方法——超边际分析方法。本文厘清了中间商在经济中存在的理由:专业中间商是交易效率充分改进(或单位交易费用不断降低)所导致的分工演进的产物,它们的出现是经济发展的一个标志。本文对于理解经济组织尤其是商业组织的结构变迁具有重要意义。 Why do middlemen exist? This article raises this question. Relying on the western economic history literature, it explains the function and economic nature of the middlemen, and points out the existence of these documents in explaining the existence of the middlemen and the economic deficiencies, and further illustrates the need for an approach to explain the evolution of economic organizations - inframarginal analysis methods. This article clarifies the reasons why middlemen exist in the economy: professional middlemen are the product of evolution of division of labor caused by the full improvement of transaction efficiency (or the continuous reduction of unit transaction costs), and their emergence is a sign of economic development. This article is of great significance for understanding the structural changes of economic organizations, especially business organizations.