1、 Managerial Managerial EconomicsEconomics Liu Houjun April, 2004Introductionn Core Problems to Deal Withn Objectn Basic Research Approachn Tools一.Core Problems for ME to Dear WithqCore Problems of Economics ME is the study of how producers and consumers use scarce resources to produce valuable commo
2、dities and distribute them among different groups. Core of Economics Limited goods Unlimited wantsGoods are scarce because there are not enough resources to produce all the goods that people want to consume.qThe Law of Scarcity How to choose?What How For whom 二.ME and Microeconomics Managerial Econo
3、mics： Economics Decision Making Statistics 管理经济学为工商管理的其他课程提供了基本的思维方法和分析工具。qMicroeconomics Most content of ME come from MicroeconomicsMicroeconomics analyzes the behavior of individual components like industries, firms, and households. Individual Components Individual consumers Firms Owner of factors
4、 三. Basic Research Approach of ME q Four Types： Individual vs total approach Static vs dynamic approach Qualitative vs quantitative approach Positive vs normative approach个量与总量分析法个量与总量分析法qMicroeconomics Individual approach. Analysis dealing with the behavior of individual elements in an economy, suc
5、h as the determin- ation of the price of a single product or the behavior of a single consumer or business firm 个量与总量分析法个量与总量分析法q Macroeconomics Total approach. Studies economic aggregates ( total national product, total employment, inflation, money supply, etc. )q Connection and differences between
6、 microecon- omics and macroeconomicsq There are no priority and relative importance between microeconomics and macroeconomicsqThe aggregate of microeconomics is not equal to the macroeconomics The whole is not always the sum of the parts The fallacy of composition静态与动态分析法静态与动态分析法qStatic approach “Ot
7、her things are held equal” ceteris paribusq Dynamic approach Affected by other factors Such as income, the prices of other commodities, taste, prediction, the change of factors etc.定性与定量分析法定性与定量分析法qQualitative approach The nature of the matter. qQuantitative approach Statistical data. Positive Econo
8、mics vs Normative Economicsq Positive Economics What is The analysis of facts and data, “the way things are” q Normative Economics What ought to be Value judgments, or goals, of public policy.实证与规范分析法实证与规范分析法四四.Tools of Analysis qLiterary Economics qMathematical Economics qGraphs Pictures at Exhibit
9、ion Demand n Individual Demand and Market Demandn Arc Elasticity and Point Elasticityn Price Elasticity of Demandn Income Elasticity of Demandn Cross Elasticity of Demand一. Individual Demand and Market Demand Demand ScheduleqDemand （ P7 9 ） Shows the amount of a commodity that the individual is will
10、ing and able to purchase in a given time period at various alternative commodity price. PX（Price of goods X in） 1 2 3 4 5 6 7 QX（Quantity demanded ) 9 8 7 6 5 4 3The demand schedule 0 1 2 3 4 5 6 7 8 9 QX (pounds per month)7654321PX($)需求曲线需求曲线注意：注意： 把需求表作成需求把需求表作成需求曲线时，人们假定商曲线时，人们假定商品的价格和数量都是品的价格和数量
11、都是无限可分的。无限可分的。d The market demand curve is the sum of all individual demand curves of the market.D市场PX($)P2P1d1d20Q3Q1Q4Q2(Q3+ Q4)(Q1+ Q2) Q (pounds per month)(d1+d2)需求曲线的基本特征需求曲线的基本特征 Downward sloping demand curve Two reasons for negative slope： q Lower price will cause more buyers.价格降低等于收入增加价格降低等于
12、收入增加 Income effect ( 收入效应收入效应 ): Substitution effect ( 替代效应替代效应 ):商品的替代作用商品的替代作用q Lower price will cause the same consumer to buy more. 需求曲线负斜率的理论基础： The value of marginal utility 边际效用价值论边际效用价值论需求的变化与需求量的变化需求的变化与需求量的变化 A change in the quantity demanded ( 需求量的变化需求量的变化 ) Negative movements along the s
13、ame demand curve. A change in demand ( 需求的变化需求的变化 ) Caused by other reasons except prices.Demand curve shift. “ 住房价格的上涨引起了对住房需求量的下降。” “ 住房价格的上涨是由于对住房的需求增加引起的。” 这两句话是否矛盾？q Other reasons of the change in demand：Income Tastes Prediction for prices or income Prices of other goods v substitute goods v co
14、mplement goods 需求曲线的特殊形状需求曲线的特殊形状 Exception: q Some conspicuous goods q Some valuable or rare goodsP($)Q0d需求曲线的特殊形状需求曲线的特殊形状 Exception:q Abnormal change P($)Q0d需求曲线的特殊形状需求曲线的特殊形状 Exception:q OthersP($)0ddQ二二. Price Elasticity of Demand q 弹性理论最早是由数理经济学派的奠基者弹性理论最早是由数理经济学派的奠基者法国法国数学家、经济学家古尔诺数学家、经济学家古尔诺
15、 （A. Cournot，18011877）提出来的，后来由马歇尔完善了弹性公式，并将其发展提出来的，后来由马歇尔完善了弹性公式，并将其发展成为完整的理论。成为完整的理论。 Elasticity( 弹性弹性 ) The ratio of the percentage change of the dependent variable to the independent variable Coefficient of elasticityYXXYXY XYe Elasticity of demand Price elasticity of demand Income elasticity of
16、demand Cross elasticity of demand Price elasticity of demand ( P( P8 58 5 ) ) A concept that measures how much the quantity demanded of a good change when its price changesQPPQPPQQe Negative value 需求价格弹性的计算方法需求价格弹性的计算方法q Arc elasticity 为避免由于起始点基数值的不同而造成计算结果上为避免由于起始点基数值的不同而造成计算结果上的差异，经济学上常采取按的差异，经济学上
17、常采取按两点的平均数值两点的平均数值计算的办法计算的办法 ，按这种方法所求出的弹性称为按这种方法所求出的弹性称为“弧弹性弧弹性” 。Formulation： 2121212122QQPPPQPPPQQQe 需求价格弹性的计算方法需求价格弹性的计算方法qPoint elasticity 指在某一价格水平点上，当价格波动很微小的一指在某一价格水平点上，当价格波动很微小的一点，所引起的需求量变化的敏感程度。点，所引起的需求量变化的敏感程度。 PX($)AFEP1P2Q1Q2Q0DBC112121OQOPPPQQ11112121OPBQAQBQEAEFPPQQ1111112121OQOPOPBQOQO
18、PPPQQeCAABCPOPOQBQ1111121121/OPPPOQQQPPQQe Expression in differential formulation Expression in differential formulation： 0PPPQQ QPPQ = lim0P 用求导数的方法计算点弹性，其优点在于用求导数的方法计算点弹性，其优点在于只要知道一条需求曲线的函数形态，就可以求只要知道一条需求曲线的函数形态，就可以求得弹性系数得弹性系数 e = lim点弹性的计算方法点弹性的计算方法QPdPdQ =PQ260 QPdPdQePP260230PP时，当5P2 .0e2260PQQ
19、PdPdQe22604PPP30222PP10e时，当2P31.0134e时，当0P0e时，当5P点弹性的计算方法举例点弹性的计算方法举例需求价格弹性的几种特殊形态需求价格弹性的几种特殊形态de = 0P ($)0Q Zero elasticity or Perfect inelasticity 需求价格弹性的几种特殊形态需求价格弹性的几种特殊形态de = 0Q Infinite elasticityP ($)需求价格弹性的几种特殊形态需求价格弹性的几种特殊形态de = 1 0QThe elasticity is always 1 P ($)需求价格弹性的几种特殊形态需求价格弹性的几种特殊形态
20、de = 1 0Q 双曲线需求价格双曲线需求价格弹性等于弹性等于-的证明如的证明如下：下： 22PaPadPdQ ，其其导导数数为为：PaQ 12 PQaQPPaQPdPdQeP ($)需求价格弹性和总收益的关系需求价格弹性和总收益的关系Three Three StateStatee，elastic e，inelastic e = ，unit elasticity P ($)e e 1 e = 1 e 60% 贫困贫困 50%60% 温饱温饱 40%50% 小康小康 0 时时为为范围经济范围经济；1e=1e 1时，时，MR 0； 当当e = 1时，时，MR =0； 当当e 1时，时，MR 0；
21、 二. Short-Run Equilibrium of the Firm q Total approach ( P437 )As the same as in the perfect competition: TR - TC The monopolist, if unregulated and free to maximize profits , will , of course , choose the price and output at which the difference between total revenue and total cost is largest. ACCB
22、STCTRACBQ1利利 润润 区区总总 利利 润润 线线$QQ00q Marginal approach ( P439 ) Also as the same as in the perfect competition market: MR = MC Under monopoly, the firm will maximize profit if it sets its output rate at the point at which marginal cost equals marginal revenue. This is generally a necessary condition
23、for profit maximization which was proved in the perfect competition model.SACSMCDMRCA0QP($)完全垄断厂商的短期利润完全垄断厂商的短期利润 In this case, the monopolist earns a profit, but this need not always be the case. It does not follow that a firm that holds a monopoly over the production of a particular product must m
24、ake a profit. There are three possibilities: making profit, break even and losing. P ($)0QP ($)0QSAC1SAC2SAC3SMCSMCP1P1DDMRMR完全垄断厂商没有一条短期供给曲线完全垄断厂商没有一条短期供给曲线 In perfect competition , one can define a unique relationship between the price of the product and the amount supplied. But in monopoly, there
25、 is no such kind of relationship 在完全垄断情况下，在完全垄断情况下，垄断厂商是价格的设立者垄断厂商是价格的设立者。可是市场价格。可是市场价格和边际收益并不相等。对于某一种市场需求曲线以及其相应的边际和边际收益并不相等。对于某一种市场需求曲线以及其相应的边际收益曲线，只能根据该厂商的收益曲线，只能根据该厂商的边际成本曲线与边际收益曲线的交点边际成本曲线与边际收益曲线的交点来来确定供给量确定供给量，其他任何点都不起作用。当整个市场需求状况发生，其他任何点都不起作用。当整个市场需求状况发生变化时，边际收益曲线也发生变化，厂商又按边际成本等于新的边变化时，边际收益曲线
26、也发生变化，厂商又按边际成本等于新的边际收益曲线的交点来确定产量，而原来的交点则失去效力。因此，际收益曲线的交点来确定产量，而原来的交点则失去效力。因此，完全垄断的厂商不能够仅由边际成本曲线的变化来确定供给量。完全垄断的厂商不能够仅由边际成本曲线的变化来确定供给量。 三. Long-Run Equilibrium of the Firm In contract to perfect competition, the long-run equilibrium of a monopolistic industry is not marked by the absence of economic p
27、rofits or losses. If a monopolist earns a short-run economic profit, it will not be confronted in the long run with competitors, unless the industry is no longer a monopoly. Thus the long-run equilibrium of an industry under monopoly may be characterized by econo- mic profits. The condition of a lon
28、g-run equilibrium of monopoly:： LMCSMCMR，and SACLAC LACLMCSAC1SMCLMCMRD0CP1QQ1P ($)In the long-run equilibrium of a firm，SMC1LMCMR ， P = P1 ， SAC1C，average profit is P1C，total profit is P1COQ1 完全垄断的效率分析及垄断势力的测定完全垄断的效率分析及垄断势力的测定BPEPEP($)CDAEFMCdMRQ0QEQEDead-weight loss of monopoly ( 无谓垄断损失无谓垄断损失) )勒纳
29、的垄断势力度勒纳的垄断势力度PMCPL q Comparison of monopoly with perfect competition First, under perfect competition, each firm operates at the point at which both long-run and short-run average costs are a minimum. However, under monopoly, although the plant that is used will produce the monopolists long-run equ
30、ilibrium output at minimum average cost, it is not the plant that will produce the product at the lowest possible average cost. Second, the output of a perfectly competitive industry tends to be greater and price tends to be lower than under monopoly.四四. Public Regulation of Monopoly Public regulati
31、on by government by government Price control ( 价格管制价格管制 )Lump sum tax ( 征收定额税征收定额税) )Per unit tax ( 征收定率税征收定率税) )价格管制价格管制Price control The government regulatory commissions can set the price or ceiling price (最高限价最高限价) at the lever at which it equals average total cost, including a “fair” rate of re
32、turn on the companys investment. The regulatory commissions also govern the extent to which price discrimination is used by the public utilities. Intricate systems of price discrimination exist in the rate structures of the electric and gas companies, the telephone companies, and so forth. SACSMCDMR
33、CEB0QP ($)KL征收定额税征收定额税Lump Sum Tax A certain amount of tax within a certain time period When the regulatory commission levy a lump sum tax to a monopolistic firm, the firms quantity of production and the price of its products will not be changed. The firms monopolistic profit will be decreased.SACSM
34、CDMRA0QP($)SAC征收定率税征收定率税Per Unit Tax The tax levied to each product or to the price of products Two methods Levied to each product (从量税从量税) Levied to the price of products (从价税从价税) When regulatory commission levy per unit tax to a monopolistic firm，some burden will be transferred to consumers. The d
35、egree of burden depends on the price elasticity of products. The smaller the price elasticity of products is, the more losses the consumers suffered. Vice versa. SACSMCDMR0QP($)SACSMCEE五五. Price Discrimination Price discrimination ( 价格差别价格差别 ) Price discrimination occurs when the same commodity is s
36、old at more than one price. Under what conditions will a monopolist be able and willing to engage in price discrimination? The necessary conditions are that buyers fall into classes with considerable differences in the price elasticity of demand for the product, and that these classes can be identif
37、ied and segregated at moderate cost. Also, it is important that buyers be unable to transfer the com-modity easily from one class to another,thus making it difficult to maintain the price differentials between classes. The differences between classes of buyers in the price elasticity of demand may b
38、e due to differences between classes in income level, differences between classes in tastes , or differences between classes in the availability of substitutes. For example, the price elasticity of demand for a certain good may be lower for the rich than for the poor. First-degree price discriminati
39、on ( 第一级价格差别第一级价格差别 ) The monopolist can charge each consumer a different price so as to extract from each consumer the full value of his or her consumers surplus. 第一级价格差第一级价格差别假定完全垄别假定完全垄断厂商能够做断厂商能够做到根据每一个到根据每一个产品对每一个产品对每一个消费者所产生消费者所产生的效用大小来的效用大小来取价取价Q0P($) Second-degree price discrimination ( 第二级价
40、格差别第二级价格差别 ) The monopolist take part, but not all, of the buyers consumers surplus.AEBFCDQP1P2P3Q1Q2Q30P($)采取分批取价采取分批取价的方法，能够的方法，能够在相当程度上在相当程度上提高其总收益提高其总收益和总利润。和总利润。 Third-degree price discrimination ( 第三级价格差别第三级价格差别 ) The monopolist will maximize its profits by allocating the total output between
41、the two classes ( or markets ) in such a way that marginal revenue in one class is equal to marginal revenue in the other class.P1P2P3Q2Q1Q3QP($)0D2D1 MRMCMR1MR2无论哪个市场，当无论哪个市场，当产品增加供给数量产品增加供给数量时，其价格必定下时，其价格必定下降，因而其边际收降，因而其边际收益也会下降。这样，益也会下降。这样，完全垄断厂商最终完全垄断厂商最终一定会将两个市场一定会将两个市场的销售量调整到的销售量调整到 上。上。 Which
42、 price of class ( or market ) larger than another depends on the price elasticity of demand of these two different classes ( or markets ). 12211111eePP The conclusion: If e e，then PP； If e e，then PP； If e e，then PP. The two preconditions of third-degree price discrimination： q The classes ( or marke
43、ts ) must be separated. 否则甲市场中的购买者获知乙市场中的价格低，便转移否则甲市场中的购买者获知乙市场中的价格低，便转移到乙市场中去购买；或反过来，乙市场中的购买者知道甲到乙市场中去购买；或反过来，乙市场中的购买者知道甲市场中的价格低，而跑到甲市场中去购买，这样，差别价市场中的价格低，而跑到甲市场中去购买，这样，差别价格则无法成立。格则无法成立。q The price elasticity are different between this two classes ( or markets ) 如果需求曲线完全相同，价格也完全一样，差别价格如果需求曲线完全相同，价格也
44、完全一样，差别价格便无法成立。便无法成立。 Monopolistic Competition and Oligopoly n Monopolistic Competitionn Oligopoly一一. Monopolistic Competition Monopolistic Competition ( 垄断竞争垄断竞争 ) Monopolistic Competition is a market structure that has elements of both monopoly and perfect competition. Under monopolistic competiti
45、on, there is a large number of firms producing and selling goods that are close substitutes, but that are not completely homogeneous from one seller to another. There is a product differentiation ( 产品差别产品差别 ) in a monopolistic competition market. ( P 446 ) Each seller tries to make its product a lit
46、tle different , by altering the physical makeup of the product, the services it offers, and other such variables. Other differences are based on brand name, image-making, advertising claims, and so forth. In this way, each seller has some amount of monopoly power, but it usually is small, because th
47、e product of other firms are very similar. Put forward by E. Chamberlin ( 张伯伦张伯伦 ). That is that if there is product differentiation, it is no longer easy to define an industry as in the perfect competition market,since each firm produce a somewhat different product. Nevertheless, E. Chamberlin beli
48、eves that it is useful to group together firms producing similar products and call them a product group. Product Group ( 产品集团产品集团 ) 张伯伦理论的假定条件有以下几种张伯伦理论的假定条件有以下几种 ：q每一种差别产品均是由许多厂商生产出来的，在同一每一种差别产品均是由许多厂商生产出来的，在同一产品类型中，它们是可以互相替换的产品类型中，它们是可以互相替换的 q 由于生产同类产品的厂商数量很多，因此对每个厂由于生产同类产品的厂商数量很多，因此对每个厂商来说，其竞争力是微
49、不足道的，当它采取竞争措施商来说，其竞争力是微不足道的，当它采取竞争措施时，很容易促使其他厂商采取报复性行为时，很容易促使其他厂商采取报复性行为 q 生产同类产品的所有厂商所面临的需求曲线和他们生产同类产品的所有厂商所面临的需求曲线和他们的成本曲线都相同的成本曲线都相同垄断竞争厂商所面临的市场需求曲线垄断竞争厂商所面临的市场需求曲线 Demand curves under monopolistic competition 02468101224681012141618202224P($)qABCDd 在垄断竞争的市场这一概念中，竞争的含义在于在垄断竞争的市场这一概念中，竞争的含义在于个个别厂商
50、面对着其他生产同类产品的别厂商面对着其他生产同类产品的“不完全竞争不完全竞争”，因，因而个别厂商不能随意确定自己产品的价格。它必须既要而个别厂商不能随意确定自己产品的价格。它必须既要考虑到自身个别产品的需求曲线，又同时要考虑到存在考虑到自身个别产品的需求曲线，又同时要考虑到存在类似替代品竞争情况下的需求曲线。类似替代品竞争情况下的需求曲线。 垄断竞争情况下的短期均衡，在垄断竞争情况下的短期均衡，在“垄断垄断”这一点上，这一点上，与完全垄断者完全相同，就是与完全垄断者完全相同，就是短期均衡条件为短期均衡条件为边际收边际收益等于上升时的边际成本益等于上升时的边际成本，即，即上升时的上升时的。这一点
