多层市场模型：用交易费用解释商人和商业的作用

以往的市场分析往往借助于单层市场模型说明价格机制，但它无法解释商人和商业的存在，无法说明市场交易为何经常要以商人为中介。本文通过建立多(双)层市场模型，以交易费用、交易效率概念为基础，说明商人产生的原因及其功能，并分析了多层市场的均衡机制，表明经济人追求交易费用最小化是导致商人的出现及各种交易方式形成的根本原因，说明商人起着降低交易费用(尤其是其中的空间费用和储管费用)、增加社会财富的重要功能，否定了以往关于商人是非生产阶级的论点。文章最后还简单探讨了网络经济中商人的地位问题。

A Model of Multiple Market:to Explain the Function of Merchant and Commerce by Cost of Transaction

By setting up a model of multiple market on the basis of cost and efficiency of transaction,the present article explains the reason and function of merchant, and studies the equilibium of multiple market.It makes known that economic man minimizing the cost of tcansaction is the reason of causing the merchant and commerce,and merchant's function in cutting down the cost of transaction.It also makes an inquiry into the merchant's role in network economy.