管理经济学MBA（英文版）

1、 Managerial Economics Liu Houjun April, 20041Introduction Core Problems to Deal With Object Basic Research Approach Tools12一.Core Problems for ME to Dear WithCore Problems of Economics ME is the study of how producers and consumers use scarce resources to produce valuable commodities and distribute

2、them among different groups. Core of Economics Limited goods Unlimited wants3Goods are scarce because there are not enough resources to produce all the goods that people want to consume.The Law of Scarcity How to choose?What How For whom 4 二.ME and Microeconomics Managerial Economics： Economics Deci

3、sion 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。5Microeconomics 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 6三. Basic Research

4、Approach of ME Four Types： Individual vs total approach Static vs dynamic approach Qualitative vs quantitative approach Positive vs normative approach7个量与总量分析法Microeconomics Individual approach. Analysis dealing with the behavior of individual elements in an economy, such as the determin- ation of t

5、he price of a single product or the behavior of a single consumer or business firm 8个量与总量分析法 Macroeconomics Total approach. Studies economic aggregates ( total national product, total employment, inflation, money supply, etc. ) Connection and differences between microecon- omics and macroeconomics T

6、here are no priority and relative importance between microeconomics and macroeconomicsThe aggregate of microeconomics is not equal to the macroeconomics The whole is not always the sum of the parts The fallacy of composition9静态与动态分析法Static approach “Other things are held equal” ceteris paribus Dynam

7、ic approach Affected by other factors Such as income, the prices of other commodities, taste, prediction, the change of factors etc.10定性与定量分析法Qualitative approach The nature of the matter. Quantitative approach Statistical data. 11 Positive Economics vs Normative Economics Positive Economics What is

8、 The analysis of facts and data, “the way things are” Normative Economics What ought to be Value judgments, or goals, of public policy.实证与规范分析法12四.Tools of Analysis Literary Economics Mathematical Economics Graphs Pictures at Exhibition 13 Demand Individual Demand and Market Demand Arc Elasticity an

9、d Point Elasticity Price Elasticity of Demand Income Elasticity of Demand Cross Elasticity of Demand214一. Individual Demand and Market Demand Demand ScheduleDemand （ P7 9 ） Shows the amount of a commodity that the individual is willing and able to purchase in a given time period at various alternati

10、ve commodity price. PX（Price of goods X in） 1 2 3 4 5 6 7 QX（Quantity demanded ) 9 8 7 6 5 4 315The demand schedule 0 1 2 3 4 5 6 7 8 9 QX (pounds per month)7654321PX($)需求曲线注意： 把需求表作成需求曲线时，人们假定商品的价格和数量都是无限可分的。d16 The market demand curve is the sum of all individual demand curves of the market.D市场PX(

11、$)P2P1d1d20Q3Q1Q4Q2(Q3+ Q4)(Q1+ Q2) Q (pounds per month)(d1+d2)17需求曲线的基本特征 Downward sloping demand curve Two reasons for negative slope： Lower price will cause more buyers.价格降低等于收入增加 Income effect ( 收入效应 ): Substitution effect ( 替代效应 ):商品的替代作用 Lower price will cause the same consumer to buy more. 18

12、 需求曲线负斜率的理论基础： The value of marginal utility 边际效用价值论19需求的变化与需求量的变化 A change in the quantity demanded ( 需求量的变化 ) Negative movements along the same demand curve. A change in demand ( 需求的变化 ) Caused by other reasons except prices.Demand curve shift. 20 “ 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。”

13、这两句话是否矛盾？21 Other reasons of the change in demand：Income Tastes Prediction for prices or income Prices of other goods substitute goods complement goods 22需求曲线的特殊形状 Exception: Some conspicuous goods Some valuable or rare goodsP($)Q0d23需求曲线的特殊形状 Exception: Abnormal change P($)Q0d24需求曲线的特殊形状 Exception:

14、 OthersP($)0ddQ25二. Price Elasticity of Demand 弹性理论最早是由数理经济学派的奠基者法国数学家、经济学家古尔诺 （A. Cournot，18011877）提出来的，后来由马歇尔完善了弹性公式，并将其发展成为完整的理论。 Elasticity( 弹性 ) The ratio of the percentage change of the dependent variable to the independent variable Coefficient of elasticity26Elasticity of demand Price elastic

15、ity of demand Income elasticity of demand Cross elasticity of demand27 Price elasticity of demand ( P8 5 ) A concept that measures how much the quantity demanded of a good change when its price changes Negative value 28需求价格弹性的计算方法 Arc elasticity 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，经济学上常采取按两点的平均数值计算的办法 ，按这种方法所

16、求出的弹性称为“弧弹性” 。Formulation： 29需求价格弹性的计算方法Point elasticity 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。 30PX($)AFEP1P2Q1Q2Q0DBC31 Expression in differential formulation： = lim 用求导数的方法计算点弹性，其优点在于只要知道一条需求曲线的函数形态，就可以求得弹性系数 e = lim点弹性的计算方法=32点弹性的计算方法举例33需求价格弹性的几种特殊形态de = 0P ($)0Q Zero elasticity or Perfect inel

17、asticity34需求价格弹性的几种特殊形态de = 0Q Infinite elasticityP ($)35需求价格弹性的几种特殊形态de = 1 0QThe elasticity is always 1 P ($)36需求价格弹性的几种特殊形态de = 1 0Q 双曲线需求价格弹性等于-的证明如下： P ($)37需求价格弹性和总收益的关系Three Statee，elastic e，inelastic e = ，unit elasticity 38P ($)e e 1 e = 1 e 60% 贫困 50%60% 温饱 40%50% 小康 0 时为范围经济；1e=1e 1时，MR 0；

18、 当e = 1时，MR =0； 当e 1时，MR 0； 187二. Short-Run Equilibrium of the Firm 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

19、 total cost is largest. 188ACCBSTCTRACBQ1利 润 区总 利 润 线$QQ00189 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 genera

20、lly a necessary condition for profit maximization which was proved in the perfect competition model.190SACSMCDMRCA0QP($)191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 part

21、icular product must make a profit. There are three possibilities: making profit, break even and losing. 192P ($)0QP ($)0QSAC1SAC2SAC3SMCSMCP1P1DDMRMR193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 mono

22、poly, there is no such kind of relationship 在完全垄断情况下，垄断厂商是价格的设立者。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来确定供给量，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。 194三. Long-Run Equilibrium of the Firm In contract to p

23、erfect competition, the long-run equilibrium of a monopolistic industry is not marked by the absence of economic profits 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 lon

24、g-run equilibrium of an industry under monopoly may be characterized by econo- mic profits. The condition of a long-run equilibrium of monopoly:： LMCSMCMR，and SACLAC 195LACLMCSAC1SMCLMCMRD0CP1QQ1P ($)In the long-run equilibrium of a firm，SMC1LMCMR ， P = P1 ， SAC1C，average profit is P1C，total profit

25、is P1COQ1 196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)勒纳的垄断势力度197 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

26、monopoly, although the plant that is used will produce the monopolists long-run equilibrium 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 tend

27、s to be lower than under monopoly.198四. Public Regulation of Monopoly Public regulation by government Price control ( 价格管制 )Lump sum tax ( 征收定额税)Per unit tax ( 征收定率税)199价格管制Price control The government regulatory commissions can set the price or ceiling price (最高限价) at the lever at which it equals a

28、verage total cost, including a “fair” rate of return 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,

29、the telephone companies, and so forth. 200SACSMCDMRCEB0QP ($)KL201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

30、firms monopolistic profit will be decreased.202SACSMCDMRA0QP($)SAC203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) Levied to the price of products (从价税) When regulatory commission levy per unit tax to a monopolistic firm，some bu

31、rden will be transferred to consumers. The degree 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. 204SACSMCDMR0QP($)SACSMCEE205五. Price Discrimination Price discrimination ( 价格差别 ) Price discr

32、imination occurs when the same commodity is sold 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 p

33、roduct, and that these classes can be identified 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. 206 The differences between classes

34、of buyers in the price elasticity of demand may be 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 t

35、han for the poor.207 First-degree price discrimination ( 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. 第一级价格差别假定完全垄断厂商能够做到根据每一个产品对每一个消费者所产生的效用大小来取价Q0P($)208 Second-degree price discrimination (

36、第二级价格差别 ) The monopolist take part, but not all, of the buyers consumers surplus.AEBFCDQP1P2P3Q1Q2Q30P($)采取分批取价的方法，能够在相当程度上提高其总收益和总利润。209 Third-degree price discrimination ( 第三级价格差别 ) The monopolist will maximize its profits by allocating the total output between the two classes ( or markets ) in su

37、ch 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，当产品增加供给数量时，其价格必定下降，因而其边际收益也会下降。这样，完全垄断厂商最终一定会将两个市场的销售量调整到 上。 210 Which price of class ( or market ) larger than another depends on the price elasticity of demand of the

38、se two different classes ( or markets ). The conclusion: If e e，then PP； If e e，then PP； If e e，then PP. 211 The two preconditions of third-degree price discrimination： The classes ( or markets ) 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，差别价格则无法成立。 The

39、 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，差别价格便无法成立。 212Monopolistic Competition and Oligopoly Monopolistic Competition Oligopoly8213一. Monopolistic Competition Monopolistic Competition ( 垄断竞争 ) Monopolistic Competition is a market structure that has

40、elements of both monopoly and perfect competition. Under monopolistic competition, 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. 214 There is a product differentiation ( 产品差别 ) in a monopol

41、istic competition market. ( P 446 ) Each seller tries to make its product a little 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, eac

42、h seller has some amount of monopoly power, but it usually is small, because the product of other firms are very similar.215 Put forward by E. Chamberlin ( 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 e

43、ach firm produce a somewhat different product. Nevertheless, E. Chamberlin believes that it is useful to group together firms producing similar products and call them a product group. Product Group ( 产品集团 )216 张伯伦理论的假定条件有以下几种 ：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 由于生产同类产品的厂商数量很多，因此对每个厂商来说，其竞争力是微不

44、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 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217垄断竞争厂商所面临的市场需求曲线 Demand curves under monopolistic competition 02468101224681012141618202224P($)qABCDd218 在垄断竞争的市场这一概念中，竞争的含义在于个别厂商面对着其他生产同类产品的“不完全竞争”，因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”这一

45、点上，与完全垄断者完全相同，就是短期均衡条件为边际收益等于上升时的边际成本，即上升时的。这一点上的产量对个别厂商的利润最大。 Equilibrium price and output in the short-run 21924681012141618202224P($)20468101224681012141618202224P($)20468101224681012141618202224204681012P($)ACBESMCDmr3d3ACHGFd2SMCmr2DACHJSMCmr1L220Equilibrium price and output in the long-run The

46、 condition of long-run equilibrium is that long-run marginal costs must equal to long-run marginal revenue. 在状态下，既没有新厂商加入市场，也没有原厂商退出市场，这时的垄断厂商处于长期均衡状态。在长期均衡状况下，垄断竞争厂商仍然能够获取已被包括在成本中的正常利润，所消失的只是超额利润。 22124681012141618202224P($)024681012qLACJLMCMNDDmrd222二.Oligopoly ( P 464 )Oligopoly (寡头) Oligopoly is

47、 a market structure characterized by a small number of firms and a great deal of interdependence, actual and perceived, among them. Each oligopolist formul- ates its policies with an eye to their effect on its rivals. Since an oligopoly contains a small number of firms, any change in the firms price

48、 or output influences the sales and profit of competitors. Moreover,since there are only a few of firms, each firm must recognize that changes in its own policies are likely to elicit changes in the policies of its competitors as well. 223 The conditions of oligopoly market 为便于分析起见，假定在一个寡头市场里的产品是同质均

49、一的。 假定寡头厂商是在完全竞争的市场中购买各种生产投入要素。 由于寡头厂商在市场中互为依存，在反托拉斯法的限制下，寡头厂商如果互相串谋，可能获利更大 。224 There are many reasons for oligopoly: One being economies of scale. Some industries want to achieve low costs. In addition, there may be economies of scale in sales promotion as well as in production, and this too may p

50、romote oligopoly. Further, there may be barriers that make it very difficult to enter the industry. Finally, of course, the number of firms in an industry may decrease in response to the desire to weaken competitive pressures. 225Oligopoly Model The Kinked Demand Curve ( 折弯需求曲线 ) This model is to ex

51、plain the rigidity of prices in oligopolistic markets. This model was due to American economist Paul Sweezy ( 保罗 斯威齐 ) who in 1939 advanced， so it is called “ Sweezy Model ” At that time, there was a widespread feeling that price in such markets tended to be rigid. A classic example occurred in the steel industry. From 1901 to 1906, the