英语翻译产品市场的均衡分析是国内《微观经济学》教材中介绍的知识点之一,其中对垄断竞争厂商长期均衡的条件之一：d需求曲线与平均成本LAC曲线相切的论述过程却语焉不详.[1]笔者疑问

Question

英语翻译
产品市场的均衡分析是国内《微观经济学》教材中介绍的知识点之一,其中对垄断竞争厂商长期均衡的条件之一：d需求曲线与平均成本LAC曲线相切的论述过程却语焉不详.[1]笔者疑问在于当垄断竞争厂商实现长期均衡时,是否只需满足均衡价格P（AR）与平均成本LAC相等,几何意义为d曲线与LAC曲线相交,而无需进一步要求：d曲线与LAC曲线相切.文章专门对此进行了探讨,结果表明：经过数学推算,证明垄断竞争厂商长期均衡时,必定满足d曲线与LAC曲线相切,不存在相交这一情况.
关键词：垄断竞争；需求函数；边际收益函数；均衡条件

Answer 1

The product market equilibrium analysis is one of the knowledge point in domestic microeconomics courses, yet it failed to explain clearly about the process how/why the demand curve and the average cost LAC curve are tangent, which is one of the conditions of monopolistic competition manufacturer's long-term balance. [1] the author's doubt is that when the monopolistic competition manufacturers is under long-term equilibrium, is it enough for just meeting the equality between the equilibrium price P (AR) and average cost LAC, while the geometrical meaning for d curve and LAC curve intersection,but with no further requirements about that d curve and LAC curve have to be tangent. The article specifically discussed about this. As the result shows, after mathematical calculation, when the monopolistic competition manufacturer is under long-term equilibrium, the d curve and LAC will must be tangent, and the situation of intersection curve is not exist .