资源描述
BETWEEN MONOPOLY AND PERFECT COMPETITION 在垄断和完全竞争之间Imperfect competition includes industries in which firms have competitors but do not face so much competition that they are price takers.不完全竞争 产业中的企业有竞争对手，但同时又没有面临使它们成为价格接受者的激烈竞争。第1页/共65页Types of Imperfectly Competitive MarketsuOligopolyuOnly a few sellers,each offering a similar or identical product to the others.uMonopolistic CompetitionuMany firms selling products that are similar but not identical.第2页/共65页不完全竞争市场的类型u寡头u只有少数几个卖者的市场结构，每个卖者都提供与其它企业相似或相同的产品。u垄断竞争u很多企业出售相似但不相同的产品。第3页/共65页Figure 1 The Four Types of Market StructureMonopoly（Chap15）Oligopoly(Chap16)Monopolistic Competition(Chap17)Perfect Competition（Chap14）Tap water Cable TV Tennis balls Crude oil Novels Movies Wheat MilkNumber of Firms?Type of Products?Many firmsOne firmFew firmsDifferentiated productsIdentical products第4页/共65页图1.市场结构的四种类型垄断（15章）寡头（16章）垄断竞争（17章）完全竞争（14章）自来水 有线电视 网球 原油小说 电影 小麦 牛奶企业数量?产品类型？许多企业一家企业几家企业有差别产量相同产品第5页/共65页Markets With Only a Few Sellers只有少数几个卖者的市场Because of the few sellers,the key feature of oligopoly is the tension between cooperation and self-interest.由于寡头市场只有几个卖者，所以寡头的关键特征是合作与利己之间的冲突。第6页/共65页MARKETS WITH ONLY A FEW SELLERS Characteristics of an Oligopoly MarketFew sellers offering similar or identical productsInterdependent firmsBest off cooperating and acting like a monopolist by producing a small quantity of output and charging a price above marginal cost第7页/共65页只有少数几个卖者的市场寡头市场的特征只有少数几个卖者提供相似或相同的产品。企业之间的行为相互影响。寡头集体合作起来并像一个垄断者那样行事生产少量产品并收取高于其边际成本的价格，它们的状况会最好。第8页/共65页A Duopoly Example双头的例子A duopoly is an oligopoly with only two members.It is the simplest type of oligopoly.双头只有两个卖者的寡头，它是最简单的寡头类型。第9页/共65页Table 1 The Demand Schedule for WaterCopyright 2004 South-Western第10页/共65页表1.水的需求曲线第11页/共65页A Duopoly Example:Price andQuantity SupplieduThe price of water in a perfectly competitive market would be driven to where the marginal cost is zero:P=MC=$0Q=120 gallonsuThe price and quantity in a monopoly market would be where total profit is maximized:P=$60Q=60 gallons第12页/共65页双头例子:价格和供给量u在竞争市场上，每个企业的生产决策使得价格等于边际成本。在水的市场上，边际成本是零。因此在竞争之下，水的均衡价格是零，均衡数量是120加仑。P=MC=0 Q=120 加仑u垄断市场的价格和产量是垄断者利润最大化时的价格和产量：P=60美元 Q=60 加仑第13页/共65页A Duopoly Example:Price andQuantity Supplied双头例子:价格和供给量uThe socially efficient quantity of water is 120 gallons,but a monopolist would produce only 60 gallons of water.社会有效率的产量是120加仑水，但是垄断者只生产60加仑水。uSo what outcome then could be expected from duopolists?我们预期双头会是什么结果呢？第14页/共65页Competition,Monopolies,and CartelsuThe duopolists may agree on a monopoly outcome.uCollusionuThe two firms may agree on the quantity to produce and the price to charge.uCarteluThe two firms may join together and act in unison.第15页/共65页竞争、垄断和卡特尔u双头 会在垄断的结果上达成一致。u勾结u两个企业之间就生产的产量或收取的价格达成协议。u卡特尔u两个企业联合起来，采取一致行动。第16页/共65页Competition,Monopolies,and Cartels竞争、垄断和卡特尔Although oligopolists would like to form cartels and earn monopoly profits,often that is not possible.Antitrust laws prohibit explicit agreements among oligopolists as a matter of public policy.虽然寡头希望形成卡特尔并赚到垄断利润，但这往往是不可能的，反托拉斯法把禁止寡头之间的公开协议作为公共政策的重点。第17页/共65页The Equilibrium for an Oligopoly寡头的均衡A Nash equilibrium is a situation in which economic actors interacting with one another each choose their best strategy given the strategies that all the others have chosen.纳什均衡相互作用的经济主体在假定所有其他主体所选战略为既定的情况下选择自己最优战略的状态。第18页/共65页The Equilibrium for an Oligopoly寡头的均衡When firms in an oligopoly individually choose production to maximize profit,they produce quantity of output greater than the level produced by monopoly and less than the level produced by competition.当寡头企业个别地选择利润最大化的产量时，它们生产的产量大于垄断的产量水平，但小于竞争的产量水平。第19页/共65页The Equilibrium for an Oligopoly寡头的均衡The oligopoly price is less than the monopoly price but greater than the competitive price(which equals marginal cost).寡头价格低于垄断价格，但高于竞争价格（竞争价格等于边际成本）。第20页/共65页Summary of Equilibrium for an OligopolyuPossible outcome if oligopoly firms pursue their own self-interests:uJoint output is greater than the monopoly quantity but less than the competitive industry quantity.uMarket prices are lower than monopoly price but greater than competitive price.uTotal profits are less than the monopoly profit.第21页/共65页寡头均衡的总结u如果寡头追求它们的利益最大化，可能以下结果：u它们生产的产量之和大于垄断的产量，但小于竞争产业的产量。u市场价格低于垄断价格，但高于竞争价格。u它们的利润之和小于垄断利润。第22页/共65页Table 1 The Demand Schedule for WaterCopyright 2004 South-Western第23页/共65页表1.水的需求曲线第24页/共65页How the Size of an Oligopoly Affects the Market OutcomeuHow increasing the number of sellers affects the price and quantity:uThe output effect:Because price is above marginal cost,selling more at the going price raises profits.uThe price effect:Raising production lowers the price and the profit per unit on all units sold.第25页/共65页寡头数量如何影响市场结果u卖者数量增加如何影响价格和产量：u产量效应:由于价格高于边际成本，在现行价格下多销售将增加利润。u价格效益:提高生产将增加总销售量，这就会降低价格并减少销售的每个单位产品带来的利润。第26页/共65页How the Size of an Oligopoly Affects the Market OutcomeuAs the number of sellers in an oligopoly grows larger,an oligopolistic market looks more and more like a competitive market.uThe price approaches marginal cost,and the quantity produced approaches the socially efficient level.第27页/共65页寡头数量如何影响市场结果u随着寡头市场上卖者数量增加，寡头市场就越来越像竞争市场。u市场价格接近于边际成本，生产量接近于社会有效率的水平。第28页/共65页Game Theory and the Economics of CooperationuGame theory is the study of how people behave in strategic situations.uStrategic decisions are those in which each person,in deciding what actions to take,must consider how others might respond to that action.第29页/共65页博弈论与合作经济学u博弈论 研究人们在各种战略情况下如何行事。u战略决策 是指每个人在决定采取什么行动时，必须如何考虑其他人对这种行动会作出什么反应的决策。第30页/共65页Game Theory and the Economics of CooperationuBecause the number of firms in an oligopolistic market is small,each firm must act strategically.uEach firm knows that its profit depends not only on how much it produced but also on how much the other firms produce.第31页/共65页博弈论与合作经济学u因为寡头市场上企业数量很少，每家企业都必须按战略行事。u每个企业都知道，它的利润不仅取决于它生产多少，还取决于其它企业生产多少。第32页/共65页The Prisoners DilemmaThe prisoners dilemma provides insight into the difficulty in maintaining cooperation.Often people(firms)fail to cooperate with one another even when cooperation would make them better off.第33页/共65页囚徒困境囚徒困境说明了维持合作的困难即使在合作使所有人状况变好时，人们在生活中也往往不能相互合作。第34页/共65页The Prisoners Dilemma 囚徒困境The prisoners dilemma is a particular“game”between two captured prisoners that illustrates why cooperation is difficult to maintain even when it is mutually beneficial.囚徒困境两个被捕获的囚犯之间的一种特殊“博弈”，说明为什么甚至在合作对双方都有利时，保持合作也是困难的。第35页/共65页Figure 2 The Prisoners DilemmaBonnies DecisionConfessRemain SilentConfessRemain SilentClydes DecisionClyde gets 8 yearsBonnie gets 8 yearsBonnie gets 20 yearsBonnie gets 1 yearBonnie goes freeClyde gets20 yearsClyde gets 1 yearClyde goes free第36页/共65页图2.囚徒困境波宁的决策坦白保持沉默坦白保持沉默克鲁得的决策克鲁得8年波宁8年波宁20年波宁1年波宁自由克鲁得20年克鲁得1年克鲁得自由第37页/共65页The Prisoners Dilemma囚徒困境The dominant strategy is the best strategy for a player to follow regardless of the strategies pursued by other players.优势战略无论其他参与者选择什么战略，对一个参与者都为最优的战略。第38页/共65页The Prisoners Dilemma囚徒困境Cooperation is difficult to maintain,because cooperation is not in the best interest of the individual player.合作是难以维持的，因为合作不符合各自的最大利益。第39页/共65页Figure 3 An Oligopoly GameIraqs DecisionHigh ProductionHigh ProductionIraq gets$40 billionIran gets$40 billionIraq gets$30 billionIran gets$60 billionIraq gets$60 billionIran gets$30 billionIraq gets$50 billionIran gets$50 billionLow ProductionLowProductionIransDecision第40页/共65页图3.寡头博弈伊拉克的决策高产量低产量高产量低产量伊朗的决策伊朗得到400亿美元伊拉克得到400亿美元伊拉克得到300亿美元伊拉克得到500亿美元伊拉克得到600亿美元伊朗得到300亿美元伊朗得到500亿美元伊朗得到600亿美元第41页/共65页Oligopolies as a Prisoners Dilemma作为囚徒困境的寡头Self-interest makes it difficult for the oligopoly to maintain a cooperative outcome with low production,high prices,and monopoly profits.自利使寡头难以维持低产量、高价格和垄断利润的合作结果。第42页/共65页Figure 4 An Arms-Race GameDecision of the United States(U.S.)ArmArmU.S.at riskUSSR at riskU.S.at risk and weakUSSR safe and powerfulU.S.safe and powerfulUSSR at risk and weakU.S.safeUSSR safeDisarmDisarmDecision of the Soviet Union(USSR)第43页/共65页图4.军备竞赛博弈美国的决策(U.S.)军备裁军军备裁军 苏联的决策(USSR)苏联在危险中美国在危险中美国在危险中并软弱美国安全美国安全而强大苏联在危险中并软弱苏联安全苏联安全并强大第44页/共65页Figure 5 An Advertising GameMarlboro s Decision AdvertiseAdvertiseMarlboro gets$3billion profitCamel gets$3billion profitCamel gets$5billion profitMarlboro gets$2billion profitCamel gets$2billion profitMarlboro gets$5billion profitCamel gets$4billion profitMarlboro gets$4billion profitDont AdvertiseDontAdvertiseCamelsDecision第45页/共65页图5.广告博弈 万宝路的决策广告不作广告广告不作广告骆驼的决策骆驼得到30亿美元利润万宝路得到30亿美元利润万宝路得到20亿美元利润万宝路得到40亿美元利润万宝路得到50亿美元利润骆驼得到20亿美元利润骆驼得到40亿美元利润骆驼得到50亿美元利润第46页/共65页Figure 6 A Common-Resource GameExxons Decision Drill TwoWellsDrill Two WellsExxon gets$4million profitTexaco gets$4million profitTexaco gets$6million profitExxon gets$3million profitTexaco gets$3million profitExxon gets$6million profitTexaco gets$5million profitExxon gets$5million profitDrill One WellDrill OneWellTexacosDecision第47页/共65页图6.共有资源博弈埃克森的决策钻两口井钻一口井钻两口井钻一口井阿尔科的决策阿尔科得到400亿美元利润埃克森得到400亿美元利润埃克森得到300亿美元利润埃克森得到500亿美元利润埃克森得到600亿美元利润阿尔科得到300亿美元利润阿尔科得到500亿美元利润阿尔科得到600亿美元利润第48页/共65页Why People Sometimes Cooperate为什么人们有时能合作Firms that care about future profits will cooperate in repeated games rather than cheating in a single game to achieve a one-time gain.在重复性博弈中，关心未来利润的参与者就会放弃欺骗的一次性好处，通过合作以达到很好的结果。第49页/共65页Figure 7 Jack and Jill Oligopoly GameJacks Decision Sell 40GallonsSell 40 GallonsJack gets$1,600 profitJill gets$1,600 profitJill gets$2,000 profitJack gets$1,500 profitJill gets$1,500 profitJack gets$2,000 profitJill gets$1,800 profitJack gets$1,800 profitSell 30 GallonsSell 30GallonsJillsDecision第50页/共65页图7.杰克和吉尔的寡头博弈杰克的决策卖40加仑卖30加仑卖40加仑卖30加仑吉尔的决策吉尔得到1600美元利润杰克得到1600美元利润杰克得到1500美元利润杰克得到1800美元利润杰克得到2000美元利润吉尔得到1500美元利润吉尔得到1800美元利润吉尔得到2000美元利润第51页/共65页Public Policy Toward OligopoliesCooperation among oligopolists is undesirable from the standpoint of society as a whole because it leads to production that is too low and prices that are too high.第52页/共65页针对寡头的公共政策从整个社会的角度来看，寡头之间的合作是不合意的，因为它使产量太低而价格太高。第53页/共65页Restraint of Trade and the Antitrust LawsuAntitrust laws make it illegal to restrain trade or attempt to monopolize a market.uSherman Antitrust Act of 1890 uClayton Act of 1914第54页/共65页限制与反托拉斯法u反托拉斯法将试图限制贸易或垄断一个市场的行为视为非法。u1890 的谢而曼反托拉斯法u1914的克莱顿法第55页/共65页Controversies over Antitrust PolicyuAntitrust policies sometimes may not allow business practices that have potentially positive effects:uResale price maintenance uPredatory pricinguTying 第56页/共65页关于反托拉斯法的争论u反托拉斯政策有时禁止有潜在正效果的企业行为:u转售价格控制 u掠夺性定价u搭售第57页/共65页Controversies over Antitrust Policy Resale Price Maintenance(or fair trade)occurs when suppliers(like wholesalers)require retailers to charge a specific amount.Predatory Pricingoccurs when a large firm begins to cut the price of its product(s)with the intent of driving its competitor(s)out of the market.Tyingwhen a firm offers two(or more)of its products together at a single price,rather than separately.第58页/共65页关于反托拉斯法的争论转售价格控制（又称公平贸易）是指供应商（如批发商）要求零售商在向消费者零售时只能收取某一特定价格的行为。掠夺性定价是指一个大企业采取降价措施将其竞争者赶出市场，建立垄断地位后再提高价格以获取垄断利润。搭售是指一个公司以单一价格同时提供两种或更多产品，而不是分开提供。第59页/共65页SummaryuOligopolists maximize their total profits by forming a cartel and acting like a monopolist.uIf oligopolists make decisions about production levels individually,the result is a greater quantity and a lower price than under the monopoly outcome.第60页/共65页小结u寡头通过形成一个卡特尔并像垄断者一样行事来使自己的总利润最大化。u如果寡头各自独立地作出生产决策，结果是产量大于垄断时的产量，价格低于垄断价格。第61页/共65页SummaryuThe prisoners dilemma shows that self-interest can prevent people from maintaining cooperation,even when cooperation is in their mutual self-interest.uThe logic of the prisoners dilemma applies in many situations,including oligopolies.第62页/共65页小结u囚徒困境表明，自利使人们即使在合作符合他们共同利益的时候也无法维持合作。u囚徒困境的逻辑适用于许多情况，包括军备竞赛、作广告、共有资源问题和寡头。第63页/共65页Summary 小结uPolicymakers use the antitrust laws to prevent oligopolies from engaging in behavior that reduces competition.决策者采用反托拉斯法来防止寡头从事减少竞争的行为。第64页/共65页感谢您的欣赏！第65页/共65页
展开阅读全文