案例：伯尔克造纸公司

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Uni,案例：,伯尔克造纸公司,西方造纸公司,西方造纸公司,埃里造纸有限公司,480,430,432,280,120,280,0.6,=168,5,230,Unit 6:Market Structure and Perfect Competition,Market Structure and Degree of Competition,Perfect Competition,Short-Run Analysis of a Perfectly Competitive Firm,Long-Run Analysis of a Perfectly Competitive Firm,General Equilibrium of Perfect Competition,Market Structure and Degree of Competition,A,Market,consists of all the actual and potential buyers and sellers of a particular product.,Market Structure,refers to the competitive environment in which the buyers and sellers of the product operate.,Four Types of Market Structure,Perfect Competition,Monopolistic Competition,Oligopoly,Monopoly,Imperfect,Competition,Degree of Competition,Perfect Competition,is the form of market organization in which,(1)there are many buyers and sellers of a product,each too small to affect the price of the product;,(2)the product is homogeneous;,(3)there is perfect mobility of resources;and,(4)economic agents have perfect knowledge of market condition.,Monopoly,is the form of market organization in which:,a single firm sells a product for which there are no close substitutes.,Entry into the industry is very difficult or impossible.,Monopolistic Competition,refers to the case where,There are many sellers of a differentiated product and,Entry into or exit from the industry is rather easy in the long run.,Oligopoly,is the case where,There are few sellers of a homogeneous or differentiated product;,While entry into the industry is possibly,it is not easy(as evidenced by the small number of firm in the industry).,Under perfect competition,the firm is a price taker,Market,One Firm,q,(unit),Q(10,4,unit),p=constant,Firms behaviors under perfect competition,Max,=TR TC,the first order condition:,d,dQ,=,d(TR),dQ,d(TC),dQ,=0;or,MR=MC;since TR=p,Q,so,MR=p and,p=MC,constant,Short-Run supply curve of a firm under perfect competition,P=MCi,Si=Si(p)=MC,-1,(p);,Si(p)=,P ATC;,0,Si(p)0,P ATC;,AVC,Si(p)0,P -TFC,停产:,pQ,TFC,TVC MC,当P AC时经济利润存在,会吸引其它厂商进入些行业,AC,MC,D,MR,P,M,Q,M,短期状况,垄断竞争的长期均衡,新厂商的进入争夺消费者,需求曲线向内移动,结果,MR=MC,(与垄断相同),P=AC,(与完全竞争相同),长期利润为零,(与完全竞争相同),达不到平均成本曲线的最低点,(与垄断相同),AC,D,D,P,Q,MC,MR,垄断竞争厂商的 短期与长期均衡,垄断竞争的性质,社会净损失,继续存在,低效率的生产,过剩的生产能力,不能位于AC曲线的最低点上,通过相同工厂的联合生产可以消除过剩的生产能力,地点,-难以联合生产,利润下降是否会抑制,革新,?,产品差异是否,过份,?,Effects of Advertising in Monopolistic Competition,AR,MR,MR,AR,MC,AC,AC,p,1,p,0,Q,0,Q,1,1,0,A Rule of Expenditure of Advertising,=pQ(p,A)C(Q)A;,the optimum expenditure should satisfied:,/,A,=p(,!Q,/,A)MC,(,Q,/,A)1=0;(p MC)(Q/A)=1;,(p MC)(Q/A),p,Q/A,=,A,pQ,E,A,/E,p,