第10章市場(chǎng)勢(shì)力：壟斷與買(mǎi)方壟斷-課件

1、第10章市場(chǎng)勢(shì)力:壟斷與買(mǎi)方壟斷1Chapter 1本章要討論的問(wèn)題壟斷壟斷勢(shì)力壟斷形成原因壟斷的社會(huì)成本2Chapter 1本章要討論的問(wèn)題買(mǎi)方壟斷買(mǎi)方壟斷勢(shì)力限制市場(chǎng)勢(shì)力: 反壟斷法3Chapter 1完全競(jìng)爭(zhēng)完全競(jìng)爭(zhēng)回顧P = LMC = LRAC長(zhǎng)期內(nèi)只存在正常利潤(rùn)或經(jīng)濟(jì)利潤(rùn)為零大量生產(chǎn)者和消費(fèi)者同質(zhì)化產(chǎn)品充分信息企業(yè)是價(jià)格的接受者4Chapter 1完全競(jìng)爭(zhēng)QQPP市場(chǎng)單個(gè)企業(yè)DSQ0P0P0D = MR = Pq0LRACLMC5Chapter 1完全壟斷完全壟斷1) 一個(gè)生產(chǎn)者 許多消費(fèi)者2)一種產(chǎn)品 (沒(méi)有替代品)3)市場(chǎng)進(jìn)入壁壘6Chapter 1完全壟斷完全壟斷企業(yè)是市場(chǎng)供

2、給方，對(duì)其產(chǎn)品的銷(xiāo)售能夠絕對(duì)控制。當(dāng)邊際收入等于邊際成本時(shí)，利潤(rùn)達(dá)到最大。7Chapter 1完全壟斷確定邊際收入作為唯一的生產(chǎn)者, 壟斷企業(yè)面對(duì)整個(gè)市場(chǎng)假定企業(yè)的需求為:P = 6 - Q8Chapter 1總收入、邊際收入及平均收入$60$0-515$5$54283433913248-12155-31價(jià)格 數(shù)量 總收入 邊際收入 平均收入PQTRMRAR9Chapter 1平均收入和邊際收入Q0123P12345674567平均收入 (需求)邊際收入10Chapter 1完全壟斷觀察1)只有降價(jià)才能增加銷(xiāo)售量2)MR MC).當(dāng)產(chǎn)量高于 MR = MC 時(shí)，收入的增加小于成本的增加(MR

3、MC完全競(jìng)爭(zhēng)P = MC21Chapter 1完全壟斷完全壟斷與完全競(jìng)爭(zhēng)的價(jià)格比較:需求價(jià)格彈性越大，價(jià)格越接近于邊際成本22Chapter 1完全壟斷需求變化在完全競(jìng)爭(zhēng)市場(chǎng)中, 市場(chǎng)供給曲線(xiàn)由邊際成本決定；對(duì)于完全壟斷企業(yè), 產(chǎn)量由邊際成本和需求曲線(xiàn)共同決定；23Chapter 1D2MR2D1MR1需求變動(dòng)導(dǎo)致價(jià)格變動(dòng)但產(chǎn)量不變QMCPP2P1Q1= Q224Chapter 1D1MR1需求變動(dòng)導(dǎo)致產(chǎn)量變動(dòng)但價(jià)格不變MCPMR2D2P1 = P2Q1Q2Q25Chapter 1完全壟斷觀察需求變化通常導(dǎo)致價(jià)格及需求量都發(fā)生變化；完全壟斷市場(chǎng)沒(méi)有供給曲線(xiàn)；26Chapter 1完全壟斷觀察在

4、相同價(jià)格水平下，完全壟斷企業(yè)可能生產(chǎn)不同數(shù)量的產(chǎn)品；在不同價(jià)格水平下，完全壟斷企業(yè)可能生產(chǎn)相同數(shù)量的產(chǎn)品；27Chapter 1MonopolyThe Effect of a TaxUnder monopoly price can sometimes rise by more than the amount of the tax.To determine the impact of a tax:t = specific taxMC = MC + tMR = MC + t : optimal production decision28Chapter 1Effect of Excise Tax o

5、n MonopolistQuantity$/QMCD = ARMRQ0P0MC + taxtQ1P1Increase in P: P0P1 increase in tax29Chapter 1QuestionSuppose: Ed = -2How much would the price change?Effect of Excise Tax on Monopolist30Chapter 1AnswerWhat would happen to profits?Effect of Excise Tax on Monopolist31Chapter 1MonopolyThe Multiplant

6、FirmFor many firms, production takes place in two or more different plants whose operating cost can differ.32Chapter 1MonopolyThe Multiplant FirmChoosing total output and the output for each plant:The marginal cost in each plant should be equal.The marginal cost should equal the marginal revenue for

7、 each plant.33Chapter 1MonopolyAlgebraically:The Multiplant Firm34Chapter 1MonopolyAlgebraically:The Multiplant Firm35Chapter 1MonopolyAlgebraically:The Multiplant Firm36Chapter 1MonopolyAlgebraically:37Chapter 1Production with Two PlantsQuantity$/QD = ARMRMC1MC2MCTMR*Q1Q2Q3P*38Chapter 1Production w

8、ith Two PlantsObservations:1)MCT = MC1 + MC22)Profit maximizing output:MCT = MR at QT and P *MR = MR*MR* = MC1 at Q1, MC* = MC2 at Q2MC1 + MC2 = MCT, Q1 + Q2 = QT, and MR = MC1 + MC2 Quantity$/QD = ARMRMC1MC2MCTMR*Q1Q2Q3P*39Chapter 1Monopoly PowerMonopoly is rare.However, a market with several firms

9、, each facing a downward sloping demand curve will produce so that price exceeds marginal cost.40Chapter 1Monopoly PowerScenario:Four firms with equal share (5,000) of a market for 20,000 toothbrushes at a price of $1.50.41Chapter 1Quantity10,0002.00QA$/Q$/Q1.501.0020,00030,0003,0005,0007,0002.001.5

10、01.001.401.60At a market priceof $1.50, elasticity ofdemand is -1.5.Market DemandThe Demand for ToothbrushesThe demand curve for Firm Adepends on how muchtheir product differs, andhow the firms compete.42Chapter 1At a market priceof $1.50, elasticity ofdemand is -1.5.Quantity10,0002.00QA$/Q$/Q1.501.

11、0020,00030,0003,0005,0007,0002.001.501.001.401.60DAMRAMarket DemandFirm A sees a much more elastic demand curve due tocompetition-Ed = -.6. StillFirm A has some monopoly power and charges a pricewhich exceeds MC.MCAThe Demand for Toothbrushes43Chapter 1Monopoly PowerMeasuring Monopoly PowerIn perfec

12、t competition: P = MR = MCMonopoly power: P MC44Chapter 1Monopoly PowerLerners Index of Monopoly PowerL = (P - MC)/PThe larger the value of L (between 0 and 1) the greater the monopoly power.L is expressed in terms of EdL = (P - MC)/P = -1/EdEd is elasticity of demand for a firm, not the market45Cha

13、pter 1Monopoly PowerMonopoly power does not guarantee profits.Profit depends on average cost relative to price.Question:Can you identify any difficulties in using the Lerner Index (L) for public policy?46Chapter 1Monopoly PowerThe Rule of Thumb for PricingPricing for any firm with monopoly power If

14、Ed is large, markup is smallIf Ed is small, markup is large47Chapter 1Elasticity of Demand and Price Markup$/Q$/QQuantityQuantityARMRMRARMCMCQ*Q*P*P*P*-MCThe more elastic isdemand, the less themarkup.48Chapter 1Markup Pricing:Supermarkets to Designer JeansSupermarkets49Chapter 1Convenience StoresMar

15、kup Pricing:Supermarkets to Designer Jeans50Chapter 1Convenience stores have more monopoly power.Question:Do convenience stores have higher profits than supermarkets?Markup Pricing:Supermarkets to Designer JeansConvenience Stores51Chapter 1Designer jeansEd = -3 to -4Price 33 - 50% MCMC = $12 - $18/p

16、airWholesale price = $18 - $27Markup Pricing:Supermarkets to Designer JeansDesigner Jeans52Chapter 1The Pricing ofPrerecorded Videocassettes19851999TitleRetail Price($)TitleRetail Price($)Purple Rain$29.98Austin Powers$10.49Raiders of the Lost Ark24.95A Bugs Life17.99Jane Fonda Workout59.95Theres So

17、mething about Mary13.99The Empire Strikes Back79.98Tae-Bo Workout24.47An Officer and a Gentleman24.95Lethal Weapon 416.99Star Trek: The Motion Picture24.95Men in Black12.99Star Wars39.98Armageddon15.8653Chapter 1What Do You Think?Should producers lower the price of videocassettes to increase sales a

18、nd revenue?The Pricing ofPrerecorded Videocassettes54Chapter 1Sources of Monopoly PowerWhy do some firms have considerable monopoly power, and others have little or none?A firms monopoly power is determined by the firms elasticity of demand.55Chapter 1Sources of Monopoly PowerThe firms elasticity of

19、 demand is determined by:1)Elasticity of market demand2)Number of firms3) The interaction among firms56Chapter 1The Social Costs of Monopoly PowerMonopoly power results in higher prices and lower quantities.However, does monopoly power make consumers and producers in the aggregate better or worse of

20、f?57Chapter 1BALost Consumer SurplusDeadweight LossBecause of the higherprice, consumers loseA+B and producer gains A-C.CDeadweight Loss from Monopoly PowerQuantityARMRMCQCPCPmQm$/Q58Chapter 1Rent SeekingFirms may spend to gain monopoly powerLobbyingAdvertisingBuilding excess capacityThe Social Cost

21、s of Monopoly Power59Chapter 1The incentive to engage in monopoly practices is determined by the profit to be gained.The larger the transfer from consumers to the firm, the larger the social cost of monopoly.The Social Costs of Monopoly Power60Chapter 1Example1996 Archer Daniels Midland (ADM) succes

22、sfully lobbied for regulations requiring ethanol be produced from cornQuestionWhy only corn?The Social Costs of Monopoly Power61Chapter 1Price RegulationRecall that in competitive markets, price regulation created a deadweight loss.Question:What about a monopoly?The Social Costs of Monopoly Power62C

23、hapter 1ARMRMCPmQmACP1Q1Marginal revenue curvewhen price is regulatedto be no higher that P1.If left alone, a monopolistproduces Qm and charges Pm.If price is lowered to P3 outputdecreases and a shortage exists. For output levels above Q1 ,the original average andmarginal revenue curves apply.If pri

24、ce is lowered to PC outputincreases to its maximum QC andthere is no deadweight loss.Price Regulation$/QQuantityP2 = PCQcP3Q3Q3Any price below P4 resultsin the firm incurring a loss. P463Chapter 1Natural MonopolyA firm that can produce the entire output of an industry at a cost lower than what it wo

25、uld be if there were several firms.The Social Costs of Monopoly Power64Chapter 1Regulating the Priceof a Natural Monopoly$/QNatural monopolies occurbecause of extensive economies of scaleQuantity65Chapter 1MCACARMR$/QQuantitySetting the price at Pr yields the largest possibleoutput;excess profit is

26、zero.QrPrPCQCIf the price were regulate to be PC,the firm would lose moneyand go out of business.PmQmUnregulated, the monopolistwould produce Qm and charge Pm.Regulating the Priceof a Natural Monopoly66Chapter 1Regulation in PracticeIt is very difficult to estimate the firms cost and demand function

27、s because they change with evolving market conditionsThe Social Costs of Monopoly Power67Chapter 1Regulation in PracticeAn alternative pricing technique-rate-of-return regulation allows the firms to set a maximum price based on the expected rate or return that the firm will earn.P = AVC + (D + T + s

28、K)/Q, whereP = price, AVC = average variable costD = depreciation, T = taxess = allowed rate of return, K = firms capital stockThe Social Costs of Monopoly Power68Chapter 1Regulation in PracticeUsing this technique requires hearings to arrive at the respective figures.The hearing process creates a r

29、egulatory lag that may benefit producers (1950s & 60s) or consumers (1970s & 80s).QuestionWho is benefiting in the 1990s?The Social Costs of Monopoly Power69Chapter 1MonopsonyA monopsony is a market in which there is a single buyer.An oligopsony is a market with only a few buyers.Monopsony power is

30、the ability of the buyer to affect the price of the good and pay less than the price that would exist in a competitive market.70Chapter 1MonopsonyCompetitive BuyerPrice takerP = Marginal expenditure = Average expenditureD = Marginal value71Chapter 1Competitive BuyerCompared to Competitive SellerQuan

31、tityQuantity$/Q$/QAR = MRD = MVME = AEP*Q*ME = MV at Q*ME = P*P* = MVP*Q*MCMR = MCP* = MRP* = MCBuyerSeller72Chapter 1MES = AEThe market supply curve is the monopsonistsaverage expenditure curveMonopsonist BuyerQuantity$/QMVQ*mP*mMonopsonyME P & above SPCQCCompetitiveP = PCQ = Q+C73Chapter 1Monopoly

32、 and MonopsonyQuantityARMRMC$/QQCPCMonopolyNote: MR = MC; AR MC; P MCP*Q*74Chapter 1Monopoly and MonopsonyQuantity$/QMVMES = AEQ*P*PCQCMonopsonyNote: ME = MV;ME AE; MV P75Chapter 1Monopoly and MonopsonyMonopolyMR MCQm PCMonopsonyME PP MVQm QCPm PC76Chapter 1Monopsony PowerA few buyers can influence

33、price (e.g. automobile industry).Monopsony power gives them the ability to pay a price that is less than marginal value. 77Chapter 1Monopsony PowerThe degree of monopsony power depends on three similar factors.1)Elasticity of market supplyThe less elastic the market supply, the greater the monopsony

34、 power.78Chapter 1Monopsony PowerThe degree of monopsony power depends on three similar factors.2)Number of buyersThe fewer the number of buyers, the less elastic the supply and the greater the monopsony power.79Chapter 1Monopsony PowerThe degree of monopsony power depends on three similar factors.3

35、)Interaction Among BuyersThe less the buyers compete, the greater the monopsony power.80Chapter 1MES = AEMES = AEMonopsony Power:Elastic versus Inelastic SupplyQuantityQuantity$/Q$/QMVMVQ*P*MV - P*P*Q*MV - P*81Chapter 1ADeadweight Loss fromMonopsony PowerDetermining the deadweight loss in monopsonyC

36、hange in sellers surplus = -A-CChange in buyers surplus = A - BChange in welfare = -A - C + A - B = -C - BInefficiency occurs because less is purchasedQuantity$/QMVMES = AEQ*P*PCQCBCDeadweight Loss82Chapter 1Monopsony PowerBilateral MonopolyBilateral monopoly is rare, however, markets with a small n

37、umber of sellers with monopoly power selling to a market with few buyers with monopsony power is more common.The Social Costs of Monopsony Power83Chapter 1Monopsony PowerQuestionIn this case, what is likely to happen to price?The Social Costs of Monopsony Power84Chapter 1Limiting Market Power: The A

38、ntitrust LawsAntitrust Laws:Promote a competitive economyRules and regulations designed to promote a competitive economy by:Prohibiting actions that restrain or are likely to restrain competitionRestricting the forms of market structures that are allowable85Chapter 1Sherman Act (1890)Section 1Prohib

39、its contracts, combinations, or conspiracies in restraint of tradeExplicit agreement to restrict output or fix pricesImplicit collusion through parallel conductLimiting Market Power: The Antitrust Laws86Chapter 11983 Six companies and six executives indicted for price of copper tubing1996Archer Dani

40、els Midland (ADM) pleaded guilty to price fixing for lysine - three sentenced to prison in 1999Limiting Market Power: The Antitrust LawsExamples of Illegal Combinations87Chapter 11999Roche A.G., BASF A.G., Rhone-Poulenc and Takeda pleaded guilty to price fixing of vitamins - fined more than $1 billi

41、on.Limiting Market Power: The Antitrust LawsExamples of Illegal Combinations88Chapter 1Sherman Act (1890)Section 2Makes it illegal to monopolize or attempt to monopolize a market and prohibits conspiracies that result in monopolization. Limiting Market Power: The Antitrust Laws89Chapter 1Clayton Act

42、 (1914)1)Makes it unlawful to require a buyer or lessor not to buy from a competitor2)Prohibits predatory pricingLimiting Market Power: The Antitrust Laws90Chapter 1Clayton Act (1914)3)Prohibits mergers and acquisitions if they “substantially lessen competition” or “tend to create a monopoly”Limitin

43、g Market Power: The Antitrust Laws91Chapter 1Robinson-Patman Act (1936)Prohibits price discrimination if it is likely to injure the competitionLimiting Market Power: The Antitrust Laws92Chapter 1Federal Trade Commission Act (1914, amended 1938, 1973, 1975)1)Created the Federal Trade Commission (FTC)2)Prohibitions against deceptive advertising, labeling, agreements with retailer to exclude competing brandsL