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1、Chapter 9 Monopoly,黄新飞 International Business School SunYat Sen University,2,A Definition Of Competition,“Competition is when everyone tries to get a monopoly.”Were going to learn about monopoly as well as one other form of imperfect competition called monopolistic competition.We shall see that pric
2、es are generally higher and outputs are lower under imperfect competition than under perfect competition.,3,The Definition of Imperfect Competition,Imperfect competition prevails in an industry whenever individual sellers have some measure of control over the price of their output.If a firm can appr
3、eciably affect the market price of its output,the firm is classified as an“imperfect competitor”.,4,Acid Test for Imperfect Competition Is Downward Tilt of Firms,d,d,d,d,Quantity,Quantity,Price,Price,Firm Demand under Perfect Competition,Firm Demand under Imperfect Competition,5,Firm Demand under Im
4、perfect Competition,d,d,Quantity,Price,An increase in its rivals prices will appreciably shift its own demand curve left to dd,d,d,6,Type of Industry Structure,7,Monopoly,Market,One Seller,Many Buyers,There is only one seller in the market selling a product for which there are no close substitutes.,
5、8,Monopoly,Exists when there is only one seller in the market selling a product for which there are no close substitutes.,The monopolist is not a price taker as was our perfectly competitive firm.Rather,it is a price maker,meaning that it exerts considerable control over what the market price will b
6、e.The monopolist has this power because it also controls quantity supplied in the market.,9,中国案例分析1：中国互联网垄断调查报告发布,互联网实验室在京发布中国互联网行业垄断状况调查及对策研究报告指出腾讯、百度、阿里巴巴均涉及垄断，其中腾讯垄断程度最大。QQ占据即时通讯市场份额的76.56%。轰动一时的3Q（360与QQ）大战就是最明显的表现。腾讯联合百度等五家公司抵制360是典型的缔结垄断协议行为。而腾讯QQ捆绑搭售的现象恰恰是最具代表性的互联网垄断手段之一。,10,Oligopoly,Market,
7、Few Sellers,Many Buyers,Few sellers;little or no difference in product;or products are differentiated.,Some of the most vigorous rivalries in the economy are in markets where there are but a few rival firms.,11,Monopoly Competition,Market,Many Seller,Many Buyers,A large number of sellers produce dif
8、ferentiated(差异化的)products.,Goods differ in their location,quality,characteristics as well as their prices.,12,Most Industries,Monopoly,Pure Competition,Market Structures,13,Market Structure,How many firms are in the industry.Whether the firms are big or small.What the firms cost structures look like
9、.How market share is divided among the firms.,14,Type of Market Structures,15,Sources of Market Imperfections,First,there are significant economies of large-scale production and decreasing costs.,Second,there are“barriers to entry”that make it difficult for new competitors to enter an industry.,16,I
10、ndustrial Competition Is Based on Cost Conditions,17,18,AC,MC,D,D,P,Q,AC,MC,P,The market allows viable(能养活的)coexistence of numerous perfect competitors.,Perfect Competition,19,AC,MC,D,D,P,Q,AC,MC,P,Only few firms can coexist in an industry.,Oligopoly,20,AC,MC,D,D,P,Q,AC,MC,P,One firm can expand to m
11、onopolize the industry.,Natural Monopoly,21,Natural Monopoly,22,Recall that with monopoly,average costs decrease throughout the relevant range of production so that one firm is able to eventually drive out all other firms by producing at lowest cost.With oligopoly,it is a few firms-not just one that
12、 drive every one else out.,#1:Scale-Economy Barriers to Entry,23,The Entry Dilemma,Assume three big firms in this industry all producing an output of AC at their MES with an equal share of the market.Can you see the dilemma for a new firm trying to enter this industry?,24,#2:Large Capital Requiremen
13、ts,It simply requires a lot of capital investment to set up the elaborate plant and equipment necessary to produce.The broader problem is that established firms with a track record may have better access to lower cost capital than new entrants.,25,AC,Output,New Firm,Old firm,#3、Absolute Cost Advanta
14、ge,AC,AC,26,课堂测试,在下列情况下政府采取什么政策？解释原因？网络服务由有限公司提供。顾客感到他们被收取的费用过高，但有限公司声称它必须收取能弥补铺设电缆的成本价格。目前飞往拉萨的两家航空公司需要政府的支持才能合并。其他想到达的航空公司却需要政府分配的着陆机位才能进行这一业务。,27,Trade Secrets,One source of such barriers is that established firms may possess valuable know-how(诀窍)in production or so-called trade secrets(商业秘密).One
15、 of the best kept secrets in the industrial world is the secret ingredient(成分)in Coca Cola.,28,Legal Restrictions,Patents(专利),Entry restrictions(准入),Foreign-trade tariffs and quotas(外贸关税和配额).,29,#4:Product DifferentiationBarriers to Entry,Any new firm entering the market would have to incur substant
16、ial advertising costs just to enjoy the same size and inelasticity of demand for its product.,30,Price、Quantity and Total Revenue,total revenue=price quantity,orTR=Pq andP=AR=TR/q,31,中国案例分析2：钻石的克拉数是中国爱情的象征,2011年英国金融时报的一篇文章写道，“这纯属营销作祟，钻石除了观念中的价值外，毫无用处。中国人被戴比尔斯说服以为钻石是女孩最好的朋友，这其实毫无逻辑。”全世界大多数的钻石都被一家戴比尔斯
17、的公司垄断着，它控制着全球60%的钻石矿。其余那40%的生产商也必须将自己家的原石以指定价格卖给戴比尔斯，否则戴比尔斯可以通过释放库存来压低市场价，令你血本无归。,32,A Quiz,Under our assumption that the monopolist wants to maximize profits,where do you think the monopolist will set the market price?Hint:Do you remember the profit maximizing rule from the last lesson?The Monopoli
18、st will maximize profits when:a)P=MCb)P is as high as possible.c)MR=MC,33,Marginal revenue,Marginal revenue(MR)is the change in revenue that is generated by an additional unit of sales.MR can be either positive or negative.,34,Total and Marginal Revenue(p162),+180,+140,+100,+60,+20,-20,-60,-100,-140
19、,-180,20,420,35,5,0,100,200,-100,10,d=AR,d=AR,MR,Even thouth MR is negative,AR,or price is still positive.Scrutinize MR lie below the dd curve of AR.MR turns negative when AR is halfway down toward zero,36,The Relation of MR and P,With demand sloping downward,P MR,37,Elasticity and MR,38,(1)(2)(3)(4
20、)(5)(6)(7)TotalTotalTotalMarginalMarginalPricerevenue costprofit revenue costQuantity P TR TC TP MR MC q($)($)($)($)($)($),0200 0146-145+200 34+180 301180180175+5+160 27?252160320200+120+120 22+100 203140420220+200+80 21+60 304120480250+230+40?+20 505100500300+200 0 60-20 706 80480370?-40 80-60 907
21、60420460-40-80100-1001108 40320570-250,39,0200 0146-145+200 34+180 30 1180180175+5+160 27+140 252160320200+120+120 22+100 203140420220+200+80 21+60 304120480250+230+40 40+20 505100500300+200 0 60-20 706 80480370+110-40 80-60 907 60420460-40-80100-100110 8 40320570-250,(1)(2)(3)(4)(5)(6)(7)TotalTotal
22、TotalMarginalMarginalPricerevenue costprofit revenue costQuantity P TR TC TP MR MC q($)($)($)($)($)($),课堂测试,某垄断者的短期成本函数为STC=0.1Q3-6Q2+140Q+3000，Q是产量，为使利润最大化，他每月生产40单位，此时的利润为1000。（1）计算满足上述条件的边际收益，销售价格和总收益。（2）若需求曲线为一条向右下方倾斜的直线，计算需求曲线均衡点的点弹性系数之值。（3）假设需求曲线是一次线性，求MR曲线以及需求函数的形式。（4）若价格为90时，该厂商是否继续生产？停业的价格降
23、到多少以下？,41,Profit-Maximizing Condition,Total Profit=Total Revenue Total Cost,orTP=TR TCBy differential calculus,the profit-maximizing conditions aredTP/dq=0 or,MR=MC,42,课堂测试,假设垄断者错误地认为他的边际收益总是等于市场价格。假定边际成本不变且没有固定成本。画图比较这个被误导的垄断者和一个聪明的垄断者的利润、消费者剩余、总剩余和无谓损失。,43,200100 0-150,2 4 6 8 10,$/q,MC,MR=MC,E,MR
24、,F,G,q,AC,44,Total Cost,Revenue and Profit,Q,P,C,TC,TR,45,课堂测试,下列各项中哪些是价格歧视的情况，哪些不是?A、降低被损坏的商品价格B、餐馆对老年公民打折C、食品生产商在报纸中放置它们产品的折扣优惠券D、飞机票在夏天飞行高峰价格更高,46,Let by gones be bygones,Let bygones(过去的)be bygones.Dont look backward.Dont cry over split milk or moan(抱怨)about yesterdays losses.Make a hard-headed(冷
25、静的)calculation of the extra costs youll incur(引起)by any decision,and weigh(权衡)these against its extra advantages.Make a decision based on marginal costs and marginal benefits.,47,The Gilded Age of America,Between 1870 and 1914 monopolists pretty much ran amuck(疯狂地).Indeed,legendary(传奇的)and often unscrupulous(肆无忌惮的)figures like John D.Rockefeller,Jay Gould,Cornelius Vanderbilt,Andrew Carnegie,and J.P.Morgan were able to corner(垄断)the markets in everything from oil and steel and the railroads to kerosene,sugar,and salt.,
