案例：伯爾克造紙公司

1、Uni案例：伯爾克造紙公司南方造紙公司北方子公司湯姆森子公司伯爾克造紙公司西方造紙公司埃里造紙有限公司4804304322801202800.6=1685230Unit 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

2、 Equilibrium of Perfect CompetitionMarket 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 Mark

3、et Structure Perfect Competition Monopolistic Competition Oligopoly Monopoly Imperfect CompetitionDegree of CompetitionPerfect 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

4、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 im

5、possible.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 ind

6、ustry 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 MarketOne Firmq(unit)Q(104unit)p=constantFirms behaviors under perfect competition Max = TR TC, the first order condition: d dQ=d(TR)dQd(TC)dQ= 0 ; orMR=MC

7、 ; since TR = p Q so, MR = p and p = MCconstantShort-Run supply curve of a firm under perfect competition P = MCi Si = Si(p) = MC-1(p); Si(p) = P ATC; 0, Si(p) 0P ATC; AVC, Si(p) 0P -TFC停產(chǎn): pQTFCTVC MC 當(dāng)P AC時經(jīng)濟利潤存在 會吸引其它廠商進入些行業(yè)ACMCDMRPMQM 短期狀況短期狀況壟斷競爭的長期均衡壟斷競爭的長期均衡 新廠商的進入爭奪消費者 需求曲線向內(nèi)移動需求曲線向內(nèi)移動 結(jié)果 MR

8、 = MC (與壟斷相同) P = AC (與完全競爭相同) 長期利潤為零長期利潤為零 (與完全競爭相同) 達不到平均成本曲線的最低達不到平均成本曲線的最低點點 (與壟斷相同)ACDDPQMCMR壟斷競爭廠商的 短期與長期均衡壟斷競爭的性質(zhì) 社會凈損失社會凈損失繼續(xù)存在 低效率的生產(chǎn) 過剩的生產(chǎn)能力過剩的生產(chǎn)能力 不能位于AC曲線的最低點上 通過相同工廠的聯(lián)合生產(chǎn)可以消除過剩的生產(chǎn)能力 地點地點 - 難以聯(lián)合生產(chǎn) 利潤下降是否會抑制革革新新? 產(chǎn)品差異是否過份過份?Effects of Advertising in Monopolistic CompetitionARMRMRARMCACACp1p0Q0Q110A Rule of Expenditure of Advertising = pQ(p,A) C(Q) A