(中文版)平狄克《微观经济学》全部课后答案教学内容
平狄克《微观经济学》课后答案 18
CHAPTER 18EXTERNALITIES AND PUBLIC GOODSThis chapter extends the discussion of market failure begun in Chapter 17. To avoid over-emphasis on definitions, stress the main theme of the chapter: the characteristics of some goods lead to situations where price is not equal to marginal cost. Rely on the discussion of market power (Chapter 10) as an example of market failure. Also, point out with each case that government intervention might not be required if property rights can be defined and transaction costs are small (Section 18.3). The first four sections present positive and negative externalities and solutions to market failure. The last two sections discuss public goods and public choice.The consumption of many goods involves the creation of externalities. Stress the divergence between social and private costs. Exercise (5) presents the classic beekeeper/apple-orchard problem, originally popularized in Meade, “External Economies and Diseconomies in a Competitive Situation,” Economic Journal (March 1952). Empirical research on this example has shown that beekeepers and orchard owners have solved many of their problems: see Cheung, “The Fable of the Bees: An Economic Investigation,” Journal of Law and Economics (April 1973).Solutions to the problems of externalities are presented in Sections 18.2 and 18.3. Section 18.2, in particular, discusses emission standards, fees, and transferable permits. Example 18.1 and Exercise (3) are simple applications of these concepts.One of the main themes of the law and economics literature since 1969 is the application of Coase’s insight on the assignment of property rights. The original article is clear and can be understood by students. Stress the problems posed by transactions costs. For a lively debate, ask students whether non-smokers should be granted the right to smokeless air in public places (see Exercise (4)). For an extended discussion of the Coase Theorem at the undergraduate level, see Polinsky, Chapters 3-6, An Introduction to Law & Economics (Little, Brown & Co., 1983).The section on common property resources emphasizes the distinction between private and social marginal costs. Example 18.5 calculates the social cost of unlimited access to common property, and the information provided is used in Exercise (7). Exercise (8) provides an extended example of managing common property.The last two sections focus on public goods and private choice. Point out the similarities and differences between public goods and other activities with externalities. Since students confuse nonrival and nonexclusive goods, create a table similar to the following and give examples to fill in the cells:The next stumbling block for students is achieving an understanding of why we add individual demand curves vertically rather than horizontally. Exercise (6) compares vertical and horizontal summation of individual demand.The presentation of public choice is a limited introduction to the subject, but you can easily expand on this material. A logical extension of this chapter is an introduction to cost-benefit analysis. For applications of this analysis, see Part III, “Empirical Analysis of Policies and Programs,” in Haveman and Margolis (eds.), Public Expenditure and Policy Analysis (Houghton Mifflin, 1983).1. Which of the following describes an externality and which does not? Explain the difference.a. A policy of restricted coffee exports in Brazil causes the U.S. price of coffee to rise,which in turn also causes the price of tea to increase.Externalities cause market inefficiencies by preventing prices from conveying accurateinformation. A policy of restricting coffee exports in Brazil causes the U.S. price ofcoffee to rise, because supply is reduced. As the price of coffee rises, consumers switchto tea, thereby increasing the demand for tea, and hence, increasing the price of tea.These are market effects, not externalities.b. An advertising blimp distracts a motorist who then hits a telephone pole.An advertising blimp is producing information by announcing the availability of somegood or service. However, its method of supplying this information can be distractingfor some consumers, especially those consumers who happen to be driving neartelephone poles. The blimp is creating a negative externality that influences thedrivers’ safety. Since the price charged by the advertising firm does not incorporate theexternality of distracting drivers, too much of this type of advertising is produced fromthe point of view of society as a whole.2. Compare and contrast the following three mechanisms for treating pollution externalities when the costs and benefits of abatement are uncertain: (a) an emissions fee, (b) an emissions standard, and (c) a system of transferable emissions permits.Since pollution is not reflected in the marginal cost of production, its emission createsan externality. Three policy tools can be used to reduce pollution: an emissions fee, anemissions standard, and a system of transferable permits. The choice between a feeand a standard will depend on the marginal cost and marginal benefit of reducingpollution. If small changes in abatement yield large benefits while adding little to cost,the cost of not reducing emissions is high. Thus, standards should be used. However, ifsmall changes in abatement yield little benefit while adding greatly to cost, the cost ofreducing emissions is high. Thus, fees should be used.A system of transferable emissions permits combines the features of fees and standardsto reduce pollution. Under this system, a standard is set and fees are used to transferpermits to the firm that values them the most (i.e., a firm with high abatement costs).However, the total number of permits can be incorrectly chosen. Too few permits willcreate excess demand, increasing price and inefficiently diverting resources to ownersof the permits. Typically, pollution control agencies implement one of threemechanisms, measure the results, reassess the success of their choice, then reset newlevels of fees or standards or select a new policy tool.3. When do externalities require government intervention, and when is such intervention unlikely to be necessary?Economic efficiency can be achieved without government intervention when theexternality affects a small number of people and when property rights are wellspecified. When the number of parties is small, the cost of negotiating an agreementamong the parties is small. Further, the amount of required information (i.e., the costsof and benefits to each party) is small. When property rights are not well specified,uncertainty regarding costs and benefits increases and efficient choices might not bemade. The costs of coming to an agreement, including the cost of delaying such anagreement, could be greater than the cost of government intervention, including theexpected cost of choosing the wrong policy instrument.4. An emissions fee is paid to the government, whereas an injurer who is sued and is held liable pays damages directly to the party harmed by an externality. What differences in the behavior of victims might you expect to arise under these two arrangements?When the price of an activity that generates an externality reflects social costs, anefficient level of the activity is maintained. The producer of the externality reduces (fornegative externalities) or increases (for positive externalities) activity away from(towards) efficient levels. If those who suffer from the externality are not compensated,they find that their marginal cost is higher (for negative externalities) or lower (forpositive externalities), in contrast to the situation in which they would be compensated.5. Why does free access to a common property resource generate an inefficient outcome?Free access to a resource means that the marginal cost to the user is less than the socialcost. The use of a common property resource by a person or firm excludes others fromusing it. For example, the use of water by one consumer restricts its use by another.Because private marginal cost is below social marginal cost, too much of the resource isconsumed by the individual user, creating an inefficient outcome.6. Public goods are both nonrival and nonexclusive. Explain each of these terms and state clearly how they differ from each other.A good is nonrival if, for any level of production, the marginal cost of providing the goodto an additional consumer is zero (although the production cost of an additional unitcould be greater than zero). A good is nonexclusive if it is impossible or very expensiveto exclude individuals from consuming it. Public goods are nonrival and nonexclusive.Commodities can be (1) exclusive and rival, (2) exclusive and nonrival, (3) nonexclusiveand rival, or (4) nonexclusive and nonrival. Most of the commodities discussed in thetext to this point have been of the first type. In this chapter, we focus on commodities ofthe last type.Nonrival refers to the production of a good or service for one more customer. It usuallyinvolves a production process with high fixed costs, such as the cost of building ahighway or lighthouse. (Remember that fixed cost depends on the period underconsideration: the cost of lighting the lamp at the lighthouse can vary over time, butdoes not vary with the number of consumers.) Nonexclusive refers to exchange, wherethe cost of charging consumers is prohibitive. Incurring the cost of identifyingconsumers and collecting from them would result in losses. Some economists focus onthe nonexclusion property of public goods because it is this characteristic that poses themost significant problems for efficient provision.7. Public television is funded in part by private donations, even though anyone with a television set can watch for free. Can you explain this phenomenon in light of the free rider problem?The free-rider problem refers to the difficulty of excluding persons from consuming anonexclusive commodity. Non-paying consumers can “free-ride” on commoditiesprovided by paying customers. Public television is funded in part by contributions.Some viewers contribute, but most watch without paying, hoping that someone else willpay so they will not. To combat this problem these stations (1) ask consumers to assesstheir true willingness to pay, then (2) ask consumers to contribute up to this amount,and (3) attempt to make everyone else feel guilty for free-riding.8. Explain why the median voter outcome need not be efficient when majority rule voting determines the level of public spending.The median voter is the citizen with the middle preference: half the voting population ismore strongly in favor of the issue and half is more strongly opposed to the issue.Under majority-rule voting, where each citizen’s vote is weighted equally, the preferredspending level on public-goods provision of the median voter will win an electionagainst any other alternative.However, majority rule is not necessarily efficient, because it weights each citizen’spreferences equally. For an efficient outcome, we would need a system that measuresand aggregates the willingness to pay of those citizens consuming the public good.Majority rule is not this system. However, as we have seen in previous chapters,majority rule is equitable in the sense that all citizens are treated equally. Thus, weagain find a trade-off between equity and efficiency.1. A number of firms located in the western portion of a town after single-family residences took up the eastern portion. Each firm produces the same product and, in the process, emits noxious fumes that adversely affect the residents of the community.a. Why is there an externality created by the firms?Noxious fumes created by firms enter the utility function of residents. We can assumethat the fumes decrease the utility of the residents (i.e., they are a negative externality)and lower property values.b. Do you think that private bargaining can resolve the problem with the externality?Explain.If the residents anticipated the location of the firms, housing prices should reflect thedisutility of the fumes; the externality would have been internalized by the housingmarket in housing prices. If the noxious fumes were not anticipated, privatebargaining could resolve the problem of the externality only if there are a relativelysmall number of parties (both firms and families) and property rights are well specified.Private bargaining would rely on each family’s willingness to pay for air quality, buttruthful revelation might not be possible. All this will be complicated by theadaptability of the production technology known to the firms and the employmentrelations between the firms and families. It is unlikely that private bargaining willresolve the problem.c. How might the community determine the efficient level of air quality?The community could determine the economically efficient level of air quality byaggregating the families’ willingne ss to pay and equating it with the marginal cost ofpollution reduction. Both steps involve the acquisition of truthful information.2. A computer programmer lobbies against copyrighting software. He argues that everyone should benefit from innovative programs written for personal computers and that exposure to a wide variety of computer programs will inspire young programmers to create even more innovative programs. Considering the marginal social benefits possibly gained by his proposal, do you agree with the programmer’s position?Computer software as information is a classic example of a public good. Since it can becostlessly copied, the marginal cost of providing software to an additional user is nearzero. Therefore, software is nonrival. (The fixed costs of creating software are high, butthe variable costs are low.) Furthermore, it is expensive to exclude consumers fromcopying and using software because copy protection schemes are available only at highcost or high inconvenience to users. Therefore, software is also nonexclusive. As bothnonrival and nonexclusive, computer software suffers the problems of public goodsprovision: the presence of free-riders makes it difficult or impossible for markets toprovide the efficient level of software. Rather than regulating this market directly, thelegal system guarantees property rights to the creators of software. If copyrightprotection were not enforced, it is likely that the software market would collapse.Therefore, we do not agree with the computer programmer.3. Four firms located at different points on a river dump various quantities of effluent into it. The effluent adversely affects the quality of swimming for homeowners who live downstream. These people can build swimming pools to avoid swimming in the river, and firms can purchase filters that eliminate harmful chemicals in the material that is dumped in the river. As a policy advisor for a regional planning organization, how would you compare and contrast the following options for dealing with the harmful effect of the effluent:a. An equal-rate effluent fee on firms located on the river.First, one needs to know the value to homeowners of swimming in the river. Thisinformation can be difficult to obtain, because homeowners will have an incentive tooverstate this value. As an upper boundary, if there are no considerations other thanswimming, one could use the cost of building swimming pools, either a pool for eachhomeowner or a public pool for all homeowners. Next, one needs to know the marginalcost of abatement. If the abatement technology is well understood, this informationshould be readily obtainable. If the abatement technology is not understood, anestimate based on the firms’ knowledge must be used.The choice of a policy tool will depend on the marginal benefits and costs of abatement.If firms are charged an equal-rate effluent fee, the firms will reduce effluents to thepoint where the marginal cost of abatement is equal to the fee. If this reduction is nothigh enough to permit swimming, the fee could be increased. Alternatively, revenuefrom the fees could be to provide swimming facilities, reducing the need for effluentreduction.b. An equal standard per firm on the level of effluent each firm can dump.Standards will be efficient only if the policy maker has complete information regardingthe marginal costs and benefits of abatement. Moreover, the standard will notencourage firms to reduce effluents further when new filtering technologies becomeavailable.c. A transferable effluent permit system, in which the aggregate level of effluent isfixed and all firms receive identical permits.A transferable effluent permit system requires the policy maker to determine theefficient effluent standard. Once the permits are distributed and a market develops,firms with a higher cost of abatement will purchase permits from firms with lowerabatement costs. However, unless permits are sold initially, rather than merelydistributed, no revenue will be generated for the regional organization.4. Recent social trends point to growing intolerance of smoking in public areas. Many people point out the negative effects of “second hand” smoke. If you are a smoker and you wish to continue smoking despite tougher anti smoking laws, describe the effect of the following legislative proposals on your behavior. As a result of these programs, do you, the individual smoker, benefit? Does society benefit as a whole?Since smoking in public areas is similar to polluting the air, the programs proposedhere are similar to those examined for air pollution. A bill to lower tar and nicotinelevels is similar to an emissions standard, and a tax on cigarettes is similar to anemissions fee. Requiring a smoking permit is similar to a system of emissions permits,assuming that the permits would not be transferable. The individual smoker in all ofthese programs is being forced to internalize the externality of “second-hand” smokeand will be worse off. Society will be better off if the benefits of a particular proposaloutweigh the cost of implementing that proposal. Unfortunately, the benefits ofreducing second-hand smoke are uncertain, and assessing those benefits is costly.a. A bill is proposed that would lower tar and nicotine levels in all cigarettes.The smoker will most likely try to maintain a constant level of consumption of nicotine,and will increase his or her consumption of cigarettes. Society may not benefit fromthis plan if the total amount of tar and nicotine released into the air is the same.b. A tax is levied on each pack of cigarettes sold.Smokers might turn to cigars, pipes, or might start rolling their own cigarettes. Theextent of the effect of a tax on cigarette consumption depends on the elasticity ofdemand for cigarettes. Again, it is questionable whether society will benefit.c. Smokers would be required to carry smoking permits at all times. These permitswould be sold by the government.Smoking permits would effectively transfer property rights to clean air from smokers tonon-smokers. The main obstacle to society benefiting from such a proposal would bethe high cost of enforcing a smoking permits system.5. A beekeeper lives adjacent to an apple orchard. The orchard owner benefits from thebees because each hive pollinates about one acre of apple trees. The orchard owner pays nothing for this service, however, because the bees come to the orchard without his having to do anything. There are not enough bees to pollinate the entire orchard, and the orchard owner must complete the pollination by artificial means, at a cost of $10 per acre of trees.Beekeeping has a marginal cost of MC = 10 + 2Q, where Q is the number of beehives.Each hive yields $20 worth of honey.a. How many beehives will the beekeeper maintain?The beekeeper maintains the number of hives that maximizes profits, when marginalrevenue is equal to marginal cost. With a constant marginal revenue of $20 (there is noinformation that would lead us to believe that the beekeeper has any market power)and a marginal cost of 10 + 2Q:20 = 10 + 2Q, or Q = 5.b. Is this the economically efficient number of hives?If there are too few bees to pollinate the orchard, the farmer must pay $10 per acre forartificial pollination. Thus, the farmer would be willing to pay up to $10 to thebeekeeper to maintain each additional hive. So, the marginal social benefit, MSB, ofeach additional hive is $30, which is greater than the marginal private benefit of $20.Assuming that the private marginal cost is equal to the social marginal cost, we setMSB = MC to determine the efficient number of hives:30 = 10 + 2Q, or Q = 10.Therefore, the beekeeper’s private choice of Q = 5 is not the socially efficient number ofhives.c. What changes would lead to the more efficient operation?The most radical change that would lead to more efficient operations would be themerger of the farmer’s business with the beekeeper’s business. This merger wouldinternalize the positive externality of bee pollination. Short of a merger, the farmerand beekeeper should enter into a contract for pollination services.7. Reconsider the common resource problem as given by Example 18.5. Suppose that crawfish popularity continues to increase, and that the demand curve shifts from C = 0.401 - 0.0064F to C = 0.50 - 0.0064F. How does this shift in demand affect the actual crawfish catch, the efficient catch, and the social cost of common access? (Hint: Use the marginal social cost and private cost curves given in the example.)The relevant information is now the following:Demand: C = 0.50 - 0.0064FMSC: C = -5.645 + 0.6509F.With an increase in demand, the demand curve for crawfish shifts upward, intersectingthe price axis at $0.50. The private cost curve has a positive slope, so additional effortmust be made to increase the catch. Since the social cost curve has a positive slope, thesocially efficient catch also increases. We may determine the socially efficient catch bysolving the following two equations simultaneously:0.50 - 0.0064F = -5.645 + 0.6509F, or F* = 9.35.To determine the price that consumers are willing to pay for this quantity, substituteF* into the equation for marginal social cost and solve for C:C = -5.645 + (0.6509)(9.35), or C = $0.44.Next, find the actual level of production by solving these equations simultaneously:Demand: C = 0.50 - 0.0064FMPC: C = -0.357 + 0.0573F0.50 - 0.0064F = -0.357 + 0.0573F, or F** = 13.45.To determine the price that consumers are willing to pay for this quantity, substituteF** into the equation for marginal private cost and solve for C:C = -0.357 + (0.0573)(13.45), or C = $0.41.Notice that the marginal social cost of producing 13.45 units isMSC = -5.645 +(0.6509)(13.45) = $3.11.With the increase in demand, the social cost is the area of a triangle with a base of 4.1million pounds (13.45 - 9.35) and a height of $2.70 ($3.11 - 0.41), or $5,535,000 morethan the social cost of the original demand.8. The Georges Bank, a highly productive fishing area off New England, can be divided into two zones in terms of fish population. Zone 1 has the higher population per square mile but is subject to severe diminishing returns to fishing effort. The daily fish catch (in tons) in Zone 1 isF 1 = 200(X1) - 2(X1) 2where X1is the number of boats fishing there. Zone 2 has fewer fish per mile but is larger, and diminishing returns are less of a problem. Its daily fish catch isF 2 = 100(X2) - (X2) 2where X2is the number of boats fishing in Zone 2. The marginal fish catch MFC in each zone can be represented asMFC1 = 200 - 4(X1) MFC2= 100 - 2(X2).There are 100 boats now licensed by the U.S. government to fish in these two zones. The fish are sold at $100 per ton. The total cost (capital and operating) per boat is constant at $1,000 per day. Answer the following questions about this situation.a. If the boats are allowed to fish where they want, with no government restriction,how many will fish in each zone? What will be the gross value of the catch?Without restrictions, the boats will divide themselves so that the average catch (AF 1and AF 2) for each boat is equal in each zone. (If the average catch in one zone is greaterthan in the other, boats will leave the zone with the lower catch for the zone with thehigher catch.) We solve the following set of equations:AF 1 = AF 2 and X 1 + X 2 = 100 where 11121120022002AF X X X X =-=- and 222222100100AF X X X X =-=-. Therefore, AF 1 = AF 2 implies200 - 2X 1 = 100 - X 2,200 - 2(100 - X 2) = 100 - X 2, or X 21003= and 320031001001=⎪⎭⎫ ⎝⎛-=X . Find the gross catch by substituting the value of X 1 and X 2 into the catch equations:()(),,,,F 444488983331332002320020021=-=⎪⎭⎫ ⎝⎛-⎪⎭⎫ ⎝⎛= and ().,,,F 2222111133333100310010022=-=⎪⎭⎫ ⎝⎛-⎪⎭⎫ ⎝⎛= The total catch is F 1 + F 2 = 6,666. At the price of $100 per ton, the value of the catch is$666,600. The average catch for each of the 100 boats in the fishing fleet is 66.66 tons.To determine the profit per boat, subtract total cost from total revenue:π = (100)(66.66) - 1,000, or π = $5,666.Total profit for the fleet is $566,000.b. If the U.S. government can restrict the boats, how many should be allocated to eachzone? What will the gross value of the catch be? Assume the total number of boats remains at 100.Assume that the government wishes to maximize the net social value of the fish catch,i.e., the difference between the total social benefit and the total social cost. Thegovernment equates the marginal fish catch in both zones, subject to the restrictionthat the number of boats equals 100:MFC 1 = MFC 2 and X 1 + X 2 = 100,MFC 1 = 200 - 4X 1 and MFC 2 = 100 - 2X 2.Setting MFC 1 = MFC 2 implies:200 - 4X 1 = 100 - 2X 2, or 200 - 4(100 - X 2) = 100 - 2X 2, or X 2 = 50 andX 1 = 100 - 50 = 50.Find the gross catch by substituting X 1 and X 2 into the catch equations:F 1 = (200)(50) - (2)(502) = 10,000 - 5,000 = 5,000 andChapter 18: Externalities and Public Goods242 F 2 = (100)(50) - 502 = 5,000 - 2,500 = 2,500.The total catch is equal to F 1 + F 2 = 7,500. At the market price of $100 per ton, thevalue of the catch is $750,000. Total profit is $650,000. Notice that the profits are notevenly divided between boats in the two zones. The average catch in Zone A is 100 tonsper boat, while the average catch in Zone B is 50 tons per boat. Therefore, fishing inZone A yields a higher profit for the individual owner of the boat.c. If additional fishermen want to buy boats and join the fishing fleet, should agovernment wishing to maximize the net value of the fish catch grant them licenses to do so? Why or why not?To answer this question, first determine the profit-maximizing number of boats in eachzone. Profits in Zone A areππA A X X X X X =--=-1002002100019000200112112b g e j,,, or . To determine the change in profit with a change in X 1 take the first derivative of theprofit function with respect to X 1:d dX X A π1119000400=-,. To determine the profit-maximizing level of output, setd dX A π1equal to zero and solve for X 1:19,000 - 400X 1 = 0, or X 1 = 47.5.Substituting X 1 into the profit equation for Zone A gives: ()()()()()()()()250,451$5.47000,15.4725.472001002=--=A π.For Zone B follow a similar procedure. Profits in Zone B areππB B X X X X X =--=-100100100090002002222222b g e j,,, or . Taking the derivative of the profit function with respect to X 2 givesd X B π229000200=-,. Setting d B π2equal to zero to find the profit-maximizing level of output gives 9,000 - 200X 2 = 0, or X 2 = 45.Substituting X 2 into the profit equation for Zone B gives:πB = (100)((100)(45) - 452) - (1,000)(45) = $202,500.Total profit from both zones is $653,750, with 47.5 boats in Zone A and 45 boats in ZoneB. Because each additional boat above 92.5 decreases total profit, the governmentshould not grant any more licenses.。
平狄克微观经济学第九本课后习题答案笔记
平狄克微观经济学第九版课后习题答案与笔记内容简介本书遵循平狄克《微观经济学》（第9版）教材的章⽬目编排，共分4篇19章，每章由三部分组成：第⼀一部分为复习笔记，总结本章的重难点内容；第⼆二部分为课（章）后复习题详解，对第9版的所有课（章）后复习题都进⾏行行了了详细的分析和解答；第三部分为课（章）后练习题详解，对第9版的所有课（章）后练习题都进⾏行行了了详细的分析和解答。
作为该教材的学习辅导书，本书具有以下⼏几个⽅方⾯面的特点：（1）整理理名校笔记，浓缩内容精华。
每章的复习笔记以平狄克所著的《微观经济学》（第9版）为主，并结合国内外其他微观经济学经典教材对各章的重难点进⾏行行了了整理理，因此，本书的内容⼏几乎浓缩了了经典教材的知识精华。
（2）解析课后习题，提供详尽答案。
本书参考⼤大量量经济学相关资料料对平狄克所著的《微观经济学》（第9版）的课（章）后习题进⾏行行了了详细的分析和解答，并对相关重要知识点进⾏行行了了延伸和归纳。
（3）补充相关要点，强化专业知识。
⼀一般来说，国外英⽂文教材的中译本不不太符合中国学⽣生的思维习惯，有些语⾔言的表述不不清或条理理性不不强⽽而给学习带来了了不不便便，因此，对每章复习笔记的⼀一些重要知识点和⼀一些习题的解答，我们在不不违背原书原意的基础上结合其他相关经典教材进⾏行行了了必要的整理理和分析。
⽬目录第1篇 导论：市场与价格 第1章 绪 论 1.1 复习笔记 1.2 课后复习题详解 1.3 课后练习题详解 第2章 供给与需求的基本原理 2.1 复习笔记 2.2 课后复习题详解 2.3 课后练习题详解第2篇 ⽣产者、消费者与竞争性市场 第3章 消费者⾏为 3.1 复习笔记 3.2 课后复习题详解 3.3 课后练习题详解 第4章 个⼈需求与市场需求 4.1 复习笔记 4.2 课后复习题详解 4.3 课后练习题详解 第4章附录 需求理论：⼀种数学的处理⽅法 第5章 不确定性与消费者⾏为 5.1 复习笔记 5.2 课后复习题详解 5.3 课后练习题详解 第6章 ⽣ 产 6.1 复习笔记 6.2 课后复习题详解 6.3 课后练习题详解 第7章 ⽣产成本 7.1 复习笔记 7.2 课后复习题详解 7.3 课后练习题详解 第7章附录 ⽣产与成本理论：⼀种数学的处理⽅法 第8章 利润最⼤化与竞争性供给 8.1 复习笔记 8.2 课后复习题详解 第9章 竞争性市场分析 9.1 复习笔记 9.2 课后复习题详解 9.3 课后练习题详解第3篇 市场结构与竞争策略 第10章 市场势⼒：垄断与买⽅垄断 10.1 复习笔记 10.2 课后复习题详解 10.3 课后练习题详解 第11章 有市场势⼒的定价 11.1 复习笔记 11.2 课后复习题详解 11.3 课后练习题详解 第11章附录 纵向联合⼚商 第12章 垄断竞争与寡头垄断 12.1 复习笔记 12.2 课后复习题详解 12.3 课后练习题详解 第13章 博弈论与竞争策略 13.1 复习笔记 13.2 课后复习题详解 13.3 课后练习题详解 第14章 投⼊要素市场 14.1 复习笔记 14.2 课后复习题详解 14.3 课后练习题详解 第15章 投资、时间与资本市场 15.1 复习笔记 15.2 课后复习题详解第4篇 信息、市场失灵与政府的⾓⾊ 第16章 ⼀般均衡与经济效率 16.1 复习笔记 16.2 课后复习题详解 16.3 课后练习题详解 第17章 信息不对称的市场 17.1 复习笔记 17.2 课后复习题详解 17.3 课后练习题详解 第18章 外部性与公共物品 18.1 复习笔记 18.2 课后复习题详解 18.3 课后练习题详解 第19章 ⾏为经济学 19.1 复习笔记 19.2 课后复习题详解 19.3 课后练习题详解附录 指定平狄克《微观经济学》教材为考研参考书⽬目的院校列列表1.2. 课后习题详解1 ⼈人们常说，⼀一个好的理理论是可以⽤用实证的、数据导向的研究来加以证伪的。
平狄克《微观经济学》(第8版)笔记和课后习题详解
第1篇导论：市场和价格第1章绪论1.1复习笔记1．微观经济学的主题（1）微观经济学的研究对象微观经济学研究的是个体经济单位（如消费者、工人、投资者、土地所有者和企业）的行为，也研究构成市场与行业的消费者和厂商的相互影响。
微观经济学的核心内容是论证亚当·斯密的“看不见的手”原理。
（2）经济模型经济模型是现代经济理论的一种主要分析方法，也称为经济数学模型，指用数学形式所表述的经济过程或经济理论结构。
现实世界的情况是由各种主要变量和次要变量构成的，因而非常复杂，只有把次要因素排除在外，才能对经济运行进行严格的分析。
运用经济模型，事先做出某些假设，可以排除掉许多次要因素，从而建立起一定的模型，然后通过运用这一模型，可以对错综复杂的现实世界做出简单的描述。
（3）经济理论的局限性在经济学、物理学或者其他学科中，没有一个理论是绝对正确的。
理论的有用性和合理性取决于它是否对其试图解释和预测的一系列现象成功地做出了解释和预测。
比如说，厂商并不总是追求其利润的最大化的，因此，厂商理论只在解释厂商某些行为（如资本投资决策的时机）时才获得了有限的成功。
尽管如此，这一理论确实解释了有关厂商和行业的行为、成长和演变方面的大量现象，所以它已经成为决策者手中一个重要的工具。
2．实证分析和规范分析（1）微观经济学的分析方法微观经济学既研究实证问题，也研究规范问题。
实证问题主要是解释和预测，规范问题则研究“应该如何”。
实证分析和规范分析都是重要的经济学分析方法。
（2）实证分析和规范分析的含义实证分析是进行经济分析的一种重要方法，特点是它对有关命题的逻辑分析，旨在理解经济过程实际是什么、将会是什么、为什么，而不涉及对结果好坏和是否公平的评价，其中不包含任何价值判断。
实证分析既有定性分析，也有定量分析。
规范分析也是经济学分析经济问题的一种方法，它以一定的价值判断作为出发点，提出行为的标准，并研究如何才能符合这些标准。
它力求说明“应该是什么”的问题，或者说，它回答这样的问题：为什么要做出这种选择，而不做出另一种选择？（3）实证分析和规范分析的关系实证分析和规范分析既有联系又有区别。
平狄克《微观经济学》(第9版)笔记和课后习题详解
平狄克《微观经济学》（第9版）笔记和课后习题详解
来自公众号精研学习网
第1篇导论：市场与价格
第1章绪论
1.1复习笔记
【知识框架】
【考点难点归纳】
考点一：微观经济学的主题（见表1-1）★
表1-1微观经济学的主题
考点二：微观经济学的分析方法——实证分析和规范分析（见表1-2）★★
表1-2微观经济学的分析方法——实证分析和规范分析
考点三：市场★
市场是指买者和卖者的集合，以及由此确定的潜在的买卖。
微观经济学中的市场不仅有买方和卖方都不会影响市场的竞争性市场，还有卖方影响市场的非竞争市场，如寡头市场、垄断竞争市场等。
市场是有范围的，不仅要考虑地理边界，还要考虑包含产品范围的大小。
如住房市场是高度当地化的，而黄金市场却是世界性的。
市场的价格是在买卖双方互动的基础上形成的。
一般而言，微观经济学考察市场均衡的价格，即一个市场上的供给等于需求时的价格。
考点四：名义价格与实际价格★★
1名义价格与实际价格的含义
名义价格是指以某些货币表示的，未经过通货膨胀的调整的价格。
实际价格则是指名义价格剔除通货膨胀因素之后的价格。
2名义价格与实际价格的关系
名义价格与实际价格的关系需要引入消费价格指数（CPI）。
居民消费价格指数是一个反映居民家庭一般所购买的消费品和服务项目价格水平变动情况的宏观经济指标，它是衡量通货膨胀的主要指标之一。
某年商品的实际价格与名义价格之间的关系为：
某年商品的实际价格＝基准年消费物价指数/计算年消费物价指数×计算年的名义价格。
平狄克《微观经济学》(第8版)笔记和课后习题详解复习答案
平狄克《微观经济学》（第8版）笔记和课后习题详解完整版>精研学习䋞>无偿试用20％资料全国547所院校视频及题库全收集考研全套>视频资料>课后答案>往年真题>职称考试第1篇导论：市场和价格第1章绪论1.1复习笔记1.2课后复习题详解1.3课后练习题详解第2章供给和需求的基本原理2.1复习笔记2.2课后复习题详解2.3课后练习题详解第2篇生产者、消费者与竞争性市场第3章消费者行为3.1复习笔记3.2课后复习题详解3.3课后练习题详解第4章个人需求和市场需求4.1复习笔记4.2课后复习题详解4.3课后练习题详解第4章附录需求理论——一种数学的处理方法第5章不确定性与消费者行为5.1复习笔记5.2课后复习题详解5.3课后练习题详解第6章生产6.1复习笔记6.2课后复习题详解6.3课后练习题详解第7章生产成本7.1复习笔记7.2课后复习题详解7.3课后练习题详解第7章附录生产与成本理论——一种数学的处理方法第8章利润最大化与竞争性供给8.1复习笔记8.3课后练习题详解第9章竞争性市场分析9.1复习笔记9.2课后复习题详解9.3课后练习题详解第3篇市场结构与竞争策略第10章市场势力：垄断和买方垄断10.1复习笔记10.2课后复习题详解10.3课后练习题详解第11章有市场势力的定价11.1复习笔记11.2课后复习题详解11.3课后练习题详解第11章附录纵向联合厂商第12章垄断竞争和寡头垄断12.1复习笔记12.2课后复习题详解12.3课后练习题详解第13章博弈论与竞争策略13.1复习笔记13.2课后复习题详解13.3课后练习题详解第14章投入要素市场14.1复习笔记14.2课后复习题详解14.3课后练习题详解第15章投资、时间与资本市场15.1复习笔记15.2课后复习题详解15.3课后练习题详解第4篇信息、市场失灵与政府的角色第16章一般均衡与经济效率16.1复习笔记16.2课后复习题详解16.3课后练习题详解第17章信息不对称的市场17.1复习笔记17.2课后复习题详解17.3课后练习题详解第18章外部性和公共物品18.1复习笔记18.2课后复习题详解附录指定平狄克《微观经济学》教材为考研参考书目的院校列表。
平狄克《微观经济学》第七版·课后习题答案中文word资料68页
第一章复习题1．市场是通过相互作用决定一种或一系列产品价格的买卖双方的集合，因此可以把市场看作决定价格的场所。
行业是出售相同的或紧密相关的产品的厂商的集合，一个市场可以包括许多行业。
2．评价一个理论有两个步骤：首先，需要检验这个理论假设的合理性；第二，把该理论的预测和事实相比较以此来验证它。
如果一个理论无法被检验的话，它将不会被接受。
因此，它对我们理解现实情况没有任何帮助。
3．实证分析解释“是什么”的问题，而规范分析解释的是“应该是什么”的问题。
对供给的限制将改变市场的均衡。
A中包括两种分析，批评这是一种“失败的政策”——是规范分析，批评其破坏了市场的竞争性——是实证分析。
B向我们说明在燃油的配给制下总社会福利的被损坏——是实证分析。
4．由于两个市场在空间上是分离的，商品在两地间的运输是套利实现的条件。
如果运输成本为零，则可以在Oklahoma购买汽油，到New Jersey出售，赚取差价；如果这个差价无法弥补运输成本则不存在套利机会。
5．商品和服务的数量与价格由供求关系决定。
鸡蛋的实际价格从1970年至1985年的下降，一方面是由于人们健康意识的提高而导致鸡蛋需求的减少，同时也因为生产成本的降低。
在这两种因素下，鸡蛋的价格下降了。
大学教育的实际价格的升高，是由于越来越多的人倾向于获得大学教育而导致需求提高，同时教育的成本也在升高。
在这两方面因素作用下，大学教育费用提高了。
6．日圆相对美圆来说，价值升高，升值前相比，兑换同样数量的日圆需要付出更多的美圆。
由汇率的变化引起购买力的变化，在日本市场出售的美国汽车，由于美圆贬值日圆升值，持有日圆的消费者将较以前支付较底的价格；而在美国市场出售的日本汽车，由于日圆升值美圆贬值，持有美圆的消费者将面对较以前提高的价格。
第二章复习题1.假设供给曲线固定，炎热天气通常会引起需求曲线右移，在当前价格上造成短期需求过剩。
消费者为获得冰激凌，愿意为每一单位冰激凌出价更高。
平狄克《微观经济学》课后答案 2
CHAPTER 2THE BASICS OF SUPPLY AND DEMANDThis chapter departs from the standard treatment of supply and demand basics found in most other intermediate microeconomics textbooks by discussing some of the world’s most important markets (wheat, gasoline, and automobiles) and teaching students how to analyze these markets with the tools of supply and demand.Although most of the discussion of economic theory in this chapter serves as a review, the real-world applications of this theory will be enlightening for students, particularly the material covered in Section 2.5 and Examples 2.5 and 2.6.Some problems plague the understanding of supply and demand analysis. One of the most common sources of confusion is between movements along the demand curve and shifts in demand. Through a discussion of the ceteris paribus assumption, stress that when representing a demand function (either with a graph or an equation), all other variables are held constant. Movements along the demand curve occur only with changes in price. As the omitted factors change, the entire demand function shifts. Students may also find a review of how to solve two equations with two unknowns helpful.To stress the quantitative aspects of the demand curve to students, make the distinction between quantity demanded as a function of price, Q = D(P), and the inverse demand function, where price is a function of the quantity demanded, P = D-1(Q). This may clarify the positioning of price on the Y-axis and quantity on the X-axis.Students may also question how the market adjusts to a new equilibrium. One simple mechanism is the partial-adjustment cobweb model. A discussion of the cobweb model (based on traditional corn-hog cycle or any other example) adds a certain realism to the discussion and is much appreciated by students.Although this chapter introduces demand, income, and cross-price elasticities, you may find it more appropriate to return to income and cross-price elasticity after demand elasticity is reintroduced in Chapter 4. If you wait, you should postpone Exercise (7) until income and cross-price elasticities are discussed.1. Suppose that unusually hot weather causes the demand curve for ice cream to shift to the right. Why will the price of ice cream rise to a new market-clearing level?Assume the supply curve is fixed. The unusually hot weather will cause a rightwardshift in the demand curve, creating short-run excess demand at the current price.Consumers will begin to bid against each other for the ice cream, putting upwardpressure on the price. The price of ice cream will rise until the quantity demanded andthe quantity supplied are equal.4. Why do long-run elasticities of demand differ from short-run elasticities? Consider two goods: paper towels and televisions. Which is a durable good? Would you expect the price elasticity of demand for paper towels to be larger in the short-run or in the long-run? Why? What about the price elasticity of demand for televisions?Long-run and short-run elasticities differ based on how rapidly consumers respond toprice changes and how many substitutes are available. If the price of paper towels, anon-durable good, were to increase, consumers might react only minimally in the shortrun. In the long run, however, demand for paper towels would be more elastic as newsubstitutes entered the market (such as sponges or kitchen towels). In contrast, thequantity demanded of durable goods, such as televisions, might change dramatically inthe short run following a price change. For example, the initial influence of a priceincrease for televisions would cause consumers to delay purchases because durablegoods are built to last longer. Eventually consumers must replace their televisions asthey wear out or become obsolete; therefore, we expect the demand for durables to bemore elastic in the long run.5. Explain why, for many goods, the long-run price elasticity of supply is larger than the short-run elasticity.The elasticity of supply is the percentage change in the quantity supplied divided by thepercentage change in price. An increase in price induces an increase in the quantitysupplied by firms. Some firms in some markets may respond quickly and cheaply toprice changes. However, other firms may be constrained by their production capacity inthe short run. The firms with short-run capacity constraints will have a short-runsupply elasticity that is less elastic. However, in the long run all firms can increasetheir scale of production and thus have a larger long-run price elasticity.6. Suppose the government regulates the prices of beef and chicken and sets them below their market-clearing levels. Explain why shortages of these goods will develop and what factors will determine the sizes of the shortages. What will happen to the price of pork? Explain briefly.If the price of a commodity is set below its market-clearing level, the quantity that firmsare willing to supply is less than the quantity that consumers wish to purchase. Theextent of the excess demand implied by this response will depend on the relativeelasticities of demand and supply. For instance, if both supply and demand are elastic,the shortage is larger than if both are inelastic. Factors such as the willingness ofconsumers to eat less meat and the ability of farmers to change the size of their herdsand produce less determine these elasticities and influence the size of excess demand.Rationing will result in situations of excess demand when some consumers are unableto purchase the quantities desired. Customers whose demands are not met willattempt to purchase substitutes, thus increasing the demand for substitutes and raisingtheir prices. If the prices of beef and chicken are set below market-clearing levels, theprice of pork will rise.7. In a discussion of tuition rates, a university official argues that the demand for admission is completely price inelastic. As evidence she notes that while the university has doubled its tuition (in real terms) over the past 15 years, neither the number nor quality of students applying has decreased. Would you accept this argument? Explain briefly. (Hint: The official makes an assertion about the demand for admission, but does she actually observe a demand curve? What else could be going on?)If demand is fixed, the individual firm (a university) may determine the shape of thedemand curve it faces by raising the price and observing the change in quantity sold.The university official is not observing the entire demand curve, but rather only theequilibrium price and quantity over the last 15 years. If demand is shifting upward, assupply shifts upward, demand could have any elasticity. (See Figure 2.7, for example.)Demand could be shifting upward because the value of a college education hasincreased and students are willing to pay a high price for each opening. More marketc. A drought shrinks the apple crop to one-third its normal size.The supply curve would shift in, causing the equilibrium price to rise and theequilibrium quantity to fall.d. Thousands of college students abandon the academic life to become apple pickers.The increased supply of apple pickers will lead to a decrease in the cost of bringingapples to market. The decreased cost of bringing apples to market results in anoutward shift of the supply curve of apples and causes the equilibrium price to fall andthe equilibrium quantity to increase.e. Thousands of college students abandon the academic life to become apple growers.This would result in an outward shift of the supply curve for apples, causing theequilibrium price to fall and the equilibrium quantity to increase.1. Consider a competitive market for which the quantities demanded and supplied (per year) at various prices are given as follows:Price($)Demand (millions) Supply (millions) 6022 14 8020 16 10018 18 12016 20 a. Calculate the price elasticity of demand when the price is $80. When the price is$100.We know that the price elasticity of demand may be calculated using equation 2.1 fromthe text:E Q Q P PP Q Q PD D D D D ==∆∆∆∆. With each price increase of $20, the quantity demanded decreases by 2. Therefore,∆∆Q P DF HG I K J =-=-22001.. At P = 80, quantity demanded equals 20 andE D =F HG I KJ -=-802001040...b g Similarly, at P = 100, quantity demanded equals 18 andE D =F HG I K J -=-1001801056...b g b. Calculate the price elasticity of supply when the price is $80. When the price is $100.The elasticity of supply is given by:E Q Q P P Q Q PS S S S S ==∆∆∆∆. With each price increase of $20, quantity supplied increases by 2. Therefore,∆∆Q SF HG I K J ==22001.. At P = 80, quantity supplied equals 16 andE S =F HG I KJ =80160105..bg .Similarly, at P = 100, quantity supplied equals 18 andE S=FH GIK J= 1001801056...bgc. What are the equilibrium price and quantity?The equilibrium price and quantity are found where the quantity supplied equals thequantity demanded at the same price. As we see from the table, the equilibrium priceis $100 and the equilibrium quantity is 18 million.d. Suppose the government sets a price ceiling of $80. Will there be a shortage, and, ifso, how large will it be?With a price ceiling of $80, consumers would like to buy 20 million, but producers willsupply only 16 million. This will result in a shortage of 4 million.2. Refer to Example 2.3 on the market for wheat. Suppose that in 1985 the Soviet Union hadbought an additional 200 million bushels of U.S. wheat. What would the free market price of wheat have been and what quantity would have been produced and sold by U.S. farmers?The following equations describe the market for wheat in 1985:QS= 1,800 + 240PandQD= 2,580 - 194P.If the Soviet Union had purchased an additional 200 million bushels of wheat, the newdemand curve 'Q D, would be equal to Q ED + 200, or'Q D= (2,580 - 194P) + 200 = 2,780 - 194PEquating supply and the new demand, we may determine the new equilibrium price,1,800 + 240P = 2,780 - 194P, or434P = 980, or P* = $2.26 per bushel.To find the equilibrium quantity, substitute the price into either the supply or demandequation, e.g.,QS= 1,800 + (240)(2.26) = 2,342andQD= 2,780 - (194)(2.26) = 2,342.3. The rent control agency of New York City has found that aggregate demand is QD= 100 - 5P measured in tens of thousands of apartments, and price, the average monthly rental rate, P, with quantity measured in hundreds of dollars. The agency also noted that the increase in Q at lower P results from more three-person families coming into the city from Long Island and demanding apartments. The city’s board of realtors acknowledges that this is agood demand estimate and has shown that supply is QS= 50 + 5P.a. If both the agency and the board are right about demand and supply, what is the freemarket price? What is the change in city population if the agency sets a maximum average monthly rental of $100, and all those who cannot find an apartment leave the city?To find the free market price for apartments, set supply equal to demand:100 - 5P = 50 + 5P, or P = $500.Substituting the equilibrium price into either the demand or supply equation todetermine the equilibrium quantity:QD= 100 - (5)(5) = 75andQ S = 50 + (5)(5) = 75.We find that at the rental rate of $500, 750,000 apartments are rented.If the rent control agency sets the rental rate at $100, the quantity supplied would thenbe 550,000 (Q S = 50 + (5)(100) = 550), a decrease of 200,000 apartments from the freemarket equilibrium. (Assuming three people per family per apartment, this wouldimply a loss of 600,000 people.) At the $100 rental rate, the demand for apartments is950,000 units, and the resultant shortage is 400,000 units.b. Suppose the agency bows to the wishes of the board and sets a rental of $900 permonth on all apartments to allow landlords a “fair” rate of return. If 50 percent of any long-run increases in apartment offerings comes from new construction, how many apartments are constructed?At a rental rate of $900, the supply of apartments would be 50 + 5(9) = 95, or 950,000units, which is an increase of 200,000 units over the free market equilibrium.Therefore, (0.5)(200,000) = 100,000 units would be constructed. Note, however, thatsince demand is only 550,000 units, 400,000 units would go unrented.4. Much of the demand for U.S. agricultural output has come from other countries. From Example 2.3, total demand is Q = 3,550 - 266P . In addition, we are told that domestic demand is Q d = 1,000 - 46P . Domestic supply is Q S = 1,800 + 240P . Suppose the export demand for wheat falls by 40 percent.a. U.S. farmers are concerned about this drop in export demand. What happens to thefree market price of wheat in the United States? Do the farmers have much reason to worry?Given total demand, Q = 3,550 - 266P , and domestic demand, Q d = 1,000 - 46P , we maysubtract and determine export demand, Q e = 2,550 - 220P .The initial market equilibrium price is found by setting total demand equal to supply:3,550 - 266P - 1,800 + 240P , orP = $3.46.There are two different ways to handle the 40 percent drop in demand. One way is toassume that the demand curve shifts down so that at all prices demand decreases by 40percent. The second way is to rotate the demand curve in a clockwise manner aroundthe vertical intercept (i.e. in the current case the demand curve would becomeQ = 3,550 - 159.6P ). We apply the former approach in the solution to exercises here.Regardless of the two approaches, the effect on prices and quantity will be qualitativelythe same, but will differ quantitatively.Therefore, if export demand decreases by 40 percent, total demand becomesQ D = Q d + 0.6Q e = 1,000 - 46P + (0.6)(2,550 - 220P ) = 2,530 - 178P .Equating total supply and total demand,1,800 + 240P = 2,530 - 178P , orP = $1.75,which is a significant drop from the market-clearing price of $3.46 per bushel. At thisprice, the market-clearing quantity is 2,219 million bushels. Total revenue hasdecreased from $9.1 billion to $3.9 billion. Most farmers would worry.b. Now suppose the U.S. government wants to buy enough wheat each year to raise theprice to $3.00 per bushel. Without export demand, how much wheat would the government have to buy each year? How much would this cost the government?With a price of $3, the market is not in equilibrium. Demand = 1000 - 46(3) = 862.Supply = 1800 + 240(3) = 2,520, and excess supply is therefore 2,520 - 862 = 1,658. Thegovernment must purchase this amount to support a price of $3, and will spend $3(1.66million) = $5.0 billion per year.5. In Example 2.6 we examined the effect of a 20 percent decline in copper demand on the price of copper, using the linear supply and demand curves developed in Section 2.5. Suppose the long-run price elasticity of copper demand were -0.4 instead of -0.8.a. Assuming, as before, that the equilibrium price and quantity are P* = 75 cents perpound and Q* = 7.5 million metric tons per year, derive the linear demand curve consistent with the smaller elasticity.Following the method outlined in Section 2.5, we solve for a and b in the demandequation Q D = a - bP . First, we know that for a linear demand function E b P D =-F H G I KJ *. Here E D = -0.4 (the long-run price elasticity), P* = 0.75 (the equilibrium price), and Q* =7.5 (the equilibrium quantity). Solving for b , -=-F H I K0407575...b , or b = 4. To find the intercept, we substitute for b , Q D (= Q *), and P (= P *) in the demandequation:7.5 = a - (4)(0.75), or a = 10.5.The linear demand equation consistent with a long-run price elasticity of -0.4 isthereforeQ D = 10.5 - 4P .b. Using this demand curve, recalculate the effect of a 20 percent decline in copperdemand on the price of copper.The new demand is 20 percent below the original (using our convention that the wholedemand curve is shifted down by 20 percent):'Q D =-=-0810548432....a f a fP P . Equating this to supply,8.4 - 3.2P = -4.5 + 16P , orP = 0.672.With the 20 percent decline in the demand, the price of copper falls to 67.2 cents perpound.6. Example 2.7 analyzes the world oil market. Using the data given in that example,a. Show that the short-run demand and competitive supply curves are indeed given byD = 24.08 - 0.06PS C = 11.74 + 0.07P .First, considering non-OPEC supply:S c = Q * = 13.With E S = 0.10 and P * = $18, E S = d (P */Q *) implies d = 0.07.Substituting for d , S c , and P in the supply equation, c = 11.74 and S c = 11.74 + 0.07P .Similarly, since Q D = 23, E D = -b (P */Q *) = -0.05, and b = 0.06. Substituting for b , Q D = 23, and P = 18 in the demand equation gives 23 = a - 0.06(18), so that a = 24.08.Hence Q D = 24.08 - 0.06P .b. Show that the long-run demand and competitive supply curves are indeed given byD = 32.18 - 0.51PS C = 7.78 + 0.29P .As above, E S = 0.4 and E D = -0.4: E S = d (P */Q *) and E D = -b(P*/Q*), implying 0.4 = d (18/13)and -0.4 = -b (18/23). So d = 0.29 and b = 0.51.Next solve for c and a :S c = c + dP and Q D = a - bP , implying 13 = c + (0.29)(18) and 23 = a - (0.51)(18).So c = 7.78 and a = 32.18.c. Use this model to calculate what would happen to the price of oil in the short-runand the long-run if OPEC were to cut its production by 6 billion barrels per year.With OPEC’s supply reduced from 10 bb/yr to 4 bb/yr, add this lower supply of 4 bb/yr to the short-run and long-run supply equations:S c ' = 4 + S c = 11.74 + 4 + 0.07P = 15.74 + 0.07P and S " = 4 + S c = 11.78 + 0.29P .These are equated with short-run and long-run demand, so that:15.74 + 0.07P = 24.08 - 0.06P ,implying that P = $64.15 in the short run; and11.78 + 0.29P = 32.18 - 0.51P ,implying that P = $24.29 in the long run.7.Refer to Example 2.8, which analyzes the effects of price controls on natural gas. a. Using the data in the example, show that the following supply and demand curvesdid indeed describe the market in 1975:Supply: Q = 14 + 2P G + 0.25P ODemand: Q = -5P G + 3.75P Owhere P G and P O are the prices of natural gas and oil, respectively. Also, verify that if the price of oil is $8.00, these curves imply a free market price of $2.00 for natural gas.To solve this problem, we apply the analysis of Section 2.5 to the definition of cross-price elasticity of demand given in Section 2.3. For example, the cross-price-elasticity of demand for natural gas with respect to the price of oil is:E Q P P Q GO G O G G=F HG I K J FH GI KJ ∆∆. ∆∆Q P G O F H G IK J is the change in the quantity of natural gas demanded, because of a small change in the price of oil. For linear demand equations,∆∆Q P G O F H G I K J is constant. If we represent demand as:Q G = a - bP G + eP O(notice that income is held constant), then∆∆Q P G OF HG I K J = e . Substituting this into the cross-price elasticity, E e P Q PO O G=F H G I K J **, where P O * and Q G * are the equilibrium price and quantity. We know that P O * = $8 and Q G* = 20 trillion cubic feet (Tcf). Solving for e , 15820.=F H G I KJ e , or e = 3.75. Similarly, if the general form of the supply equation is represented as:Q G = c + dP G + gP O , the cross-price elasticity of supply is g P Q OG**F H G I K J , which we know to be 0.1. Solving for g , ⎪⎭⎫ ⎝⎛=2081.0g , or g = 0.25. The values for d and b may be found with equations 2.5a and 2.5b in Section 2.5. Weknow that E S = 0.2, P* = 2, and Q* = 20. Therefore,⎪⎭⎫ ⎝⎛=2022.0d , or d = 2.Also, E D = -0.5, so⎪⎭⎫ ⎝⎛=-2025.0b , or b = -5. By substituting these values for d, g, b , and e into our linear supply and demandequations, we may solve for c and a :20 = c + (2)(2) + (0.25)(8), or c = 14,and20 = a - (5)(2) + (3.75)(8), or a = 0.If the price of oil is $8.00, these curves imply a free market price of $2.00 for naturalgas. Substitute the price of oil in the supply and demand curves to verify theseequations. Then set the curves equal to each other and solve for the price of gas.14 + 2P G + (0.25)(8) = -5P G + (3.75)(8), 7P G = 14, orP G = $2.00.b. Suppose the regulated price of gas in 1975 had been $1.50 per million cubic feet,instead of $1.00. How much excess demand would there have been?With a regulated price of $1.50 for natural gas and a price of oil equal to $8.00 perbarrel,Demand: Q D = (-5)(1.50) + (3.75)(8) = 22.5, andSupply: Q S = 14 + (2)(1.5) + (0.25)(8) = 19.With a supply of 19 Tcf and a demand of 22.5 Tcf, there would be an excess demand of3.5 Tcf.c. Suppose that the market for natural gas had not been regulated. If the price of oilhad increased from $8 to $16, what would have happened to the free market price of natural gas?If the price of natural gas had not been regulated and the price of oil had increasedfrom $8 to $16, thenDemand: Q D = -5P G + (3.75)(16) = 60 - 5P G , andSupply: Q S = 14 + 2P G + (0.25)(16) = 18 + 2P G .Equating supply and demand and solving for the equilibrium price,18 + 2P G = 60 - 5P G , or P G = $6.The price of natural gas would have tripled from $2 to $6.。
平狄克《微观经济学》版习题详解 供给和需求的基本原理
平狄克《微观经济学》（第7版）第2章供给和需求的基本原理课后复习题详解跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是宝贵的财富，这或许能帮你少走弯路，躲开一些陷阱。
以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。
1．假定异常炎热的天气会使冰淇淋的需求曲线向右移动，解释为什么冰淇淋价格会上升到一个新的市场出清水平。
答：如图2-3所示，假设短期内供给完全无弹性，则供给曲线是垂直的。
供给曲线S与初始的需求曲线D相交，确定均衡价格为1P，均衡数量为1Q。
异常炎热的天气1会使冰淇淋的需求曲线向右移动，在当前价格P上造成短期需求过剩，消费者为获1得冰淇淋，愿意为每一单位冰淇淋出价更高。
在需求压力下，冰淇淋价格将上升，直到供给与需求达到均衡。
图2-3 冰淇淋的供求分析2．请运用供给曲线和需求曲线来说明以下各事件会怎样影响黄油的价格、销售量及购买量：（1）人造黄油价格上升；（2）牛奶价格上升；（3）平均收入水平下降。
答：（1）人造黄油和黄油是一对替代品。
人造黄油价格上升将导致黄油消费量的上升，因此黄油的需求曲线将从D向右移动至2D，均衡价格将从1P上升至2P，均衡1数量将从Q增加至2Q，如图2-4所示。
1图2-4 人造黄油价格上升的影响（2）牛奶是黄油的主要原料。
牛奶价格上升将增加黄油制造成本。
黄油的供给曲线将从S向左移动至2S，在更高的价格2P实现均衡，同时供给量减少到2Q，如图12-5所示。
图2-5 牛奶价格上升的影响（3）假设黄油是正常商品。
平均收入水平下降将导致需求曲线从D向左移动至1D，结果价格降至2P，需求量也下降至2Q，如图2-6所示。
2图2-6 平均收入下降的影响3．如果玉米片价格上升3%而使其需求量下降6%，那么玉米片的需求价格弹性是多少？解：需求价格弹性指某种商品需求量变化的百分率与价格变化的百分率之比，它用来测度商品需求量变动对于商品自身价格变动反应的敏感性程度。
平狄克微观经济学课后习题答案(中文)第九版
平狄克微观经济学课后习题答案(中文)第九版第一章经济学的研究对象和方法习题1-1答案：经济学的研究对象是人类的经济活动，包括生产、交换、分配和消费等方面。
经济学的研究方法主要包括观察、实证分析和理论分析等。
习题1-2答案：观察是经济学研究的基础，通过观察可以获得经济现象的真实情况。
实证分析是基于观察数据进行的定量分析，通过统计分析等方法来验证经济理论的有效性。
理论分析是通过构建模型和假设来研究和解释经济现象的原因和机制。
习题1-3答案：经济学的分类有宏观经济学和微观经济学两个主要方向。
宏观经济学研究整个经济体系的总体运行规律，涉及国民经济的总量问题；微观经济学研究个体经济单位（如个人、家庭、企业）的经济行为和决策，涉及资源配置和效率问题。
习题1-4答案：正式的经济学的定义是一个关于个体与群体选择的社会科学。
它研究人们如何利用有限的资源，以满足无限的欲望。
经济学通过分析经济行为的原理和规律，帮助人们做出更好的经济决策，实现资源的高效配置和社会福利的最大化。
第二章需求、供给与市场均衡习题2-1答案：需求是指个人或市场上愿意购买某种商品或服务的能力和意愿。
供给是指个人或企业愿意出售某种商品或服务的能力和意愿。
习题2-2答案：需求曲线是描述消费者对某种商品或服务需求量与价格之间关系的曲线。
供给曲线是描述生产者或企业对某种商品或服务供给量与价格之间关系的曲线。
习题2-3答案：当市场需求量大于市场供给量时，市场处于短缺状态，价格将上涨；当市场供给量大于市场需求量时，市场处于过剩状态，价格将下降。
只有当市场需求量等于市场供给量时，市场达到均衡状态，价格稳定。
习题2-4答案：市场需求量变化的因素包括消费者收入、商品价格、相关商品价格和个人偏好等。
市场供给量变化的因素包括生产成本、生产技术、生产要素价格和政府政策等。
第三章边际分析及其应用习题3-1答案：边际分析是指在某一决策过程中，考察增加或减少一单元该决策的收益或成本的变化量。
微观经济学课后答案(全)
微观经济学课后答案（全）第二章需求、供给和均衡价格1. 已知某一时期内某商品的需求函数为Qd＝50－5P，供给函数为Qs＝－10＋5P。
(1)求均衡价格Pe和均衡数量Qe，并作出几何图形。
(2)假定供给函数不变，由于消费者收入水平提高，使需求函数变为Qd＝60－5P。
求出相应的均衡价格Pe和均衡数量Qe，并作出几何图形。
(3)假定需求函数不变，由于生产技术水平提高，使供给函数变为Qs＝－5＋5P。
求出相应的均衡价格Pe和均衡数量Qe，并作出几何图形。
(4)利用(1)、(2)和(3)，说明静态分析和比较静态分析的联系和区别。
(5)利用(1)、(2)和(3)，说明需求变动和供给变动对均衡价格和均衡数量的影响。
解答：(1)将需求函数Qd＝50－5P和供给函数Qs＝－10＋5P 代入均衡条件Qd＝Qs，有50－5P＝－10＋5P得 Pe＝6将均衡价格Pe＝6代入需求函数Qd＝50－5P，得Qe＝50－5×6＝20或者，将均衡价格Pe＝6代入供给函数Qs＝－10＋5P，得Qe＝－10＋5×6＝20所以，均衡价格和均衡数量分别为Pe＝6，Qe＝20。
如图2—1所示。
图2—1(2)将由于消费者收入水平提高而产生的需求函数Qd＝60－5P 和原供给函数Qs＝－10＋5P代入均衡条件Qd＝Qs，有60－5P＝－10＋5P得 Pe＝7将均衡价格Pe＝7代入Qd＝60－5P，得Qe＝60－5×7＝25或者，将均衡价格Pe＝7代入Qs＝－10＋5P，得Qe＝－10＋5×7＝25所以，均衡价格和均衡数量分别为Pe＝7，Qe＝25。
如图2—2所示。
图2—2(3)将原需求函数Qd＝50－5P和由于技术水平提高而产生的供给函数Qs＝－5＋5P代入均衡条件Qd＝Qs，有50－5P＝－5＋5P得 Pe＝5.5将均衡价格Pe＝5.5代入Qd＝50－5P，得Qe＝50－5×5.5＝22.5或者，将均衡价格Pe＝5.5代入Qs＝－5＋5P，得Qe＝－5＋5×5.5＝22.5所以，均衡价格和均衡数量分别为Pe＝5.5，Qe＝22.5。
平狄克《微观经济学》课后答案 10
CHAPTER 10MARKET POWER: MONOPOLY AND MONOPSONYIn most textbooks, the title of this chapter would be “Monopoly,” and monopsony would be found in a section of the chapter on factor markets. This text, however, gives monopoly and monopsony parallel treatment. There is an initial discussion of monopoly (Sections 1-4), a briefer discussion of monopsony (Section 5), and a joint consideration of the two (Section 6). Exercises (1) through (5) focus on the monopolist’s determination of a profit-maximizing output. Exercises (6) and (7) explore the multiplant firm. Exercise (8) examines the decision in the U.S. antitrust case against Alcoa. Exercises (10) and (12) examine monopsony power. Exercises (9), (13),(14), and (15) focus on price regulation.Although previous chapters have presented the rule for profit maximization, you should briefly review marginal revenue and price elasticity of demand through a careful derivation of Equation 10.1. A discussion of the derivation of Equation 10.1 will elucidate the geometry of Figure 10.3: illustrate that because the monopolist chooses a quantity such that marginal revenue is positive, demand at that quantity is elastic. Equation 10.1 also leads directly to the Lerner Index in Section 10.2. This pro vides fruitful ground for a discussion of a monopolist’s market power. For example, if E d is large (e.g., because of close substitutes), then (1) the demand curve is flat, (2) the marginal revenue curve is flat (although steeper than the demand curve), and (3) the monopolist has little power to raise price above marginal cost. To reinforce these points, introduce a non-linear demand curve by, for example, showing the location of the marginal revenue curve for a unit-elastic demand curve. Once this concept has been clearly presented, the discussion of the effect of an excise tax on a monopolist with non-linear demand (Figure 10.5) will not seem out of place.The social response to market power provides a good topic for class discussion, and this topic can be introduced by comparing the deadweight loss with the analysis of market intervention given in Chapter 9. For example, compare Figure 10.9 with Figure 9.6. Because Exercises (9), (13), and (15) involve “kinked marginal revenue curves,” you should pres ent Figure 10.10 if you plan to assign those problems. Although Figure 10.10 is complicated, exposure to it here will help when it reappears in Chapter 12.1. When marginal cost is greater than marginal revenue, the incremental cost of the last unit produced is greater than incremental revenue. The firm would increase its profit by not producing the last unit. It should continue to reduce production, thereby decreasing marginal cost and increasing marginal revenue, until marginal cost is equal to marginal revenue.2. We can show that this measure of market power is equal to the negative inverse of the price elasticity of demand.P MC P E D-=-1 The equation implies that, as the elasticity increases (demand becomes more elastic), the inverse of elasticity decreases and the measure of market power decreases. Therefore, as elasticity increases (decreases), the firm has less (more) power to increase price above marginal cost.3. The monopolist’s output decision depends not only on mar ginal cost, but also on the demand curve. Shifts in demand do not trace out a series of prices and quantities that we can identify as the supply curve for the firm. Instead, shifts in demand lead to changes in price, output, or both. Thus, there is no one-to-one correspondence between the price and the seller’s quantity; therefore, a monopolized market lacks a supply curve.4. The degree of monopoly power or market power enjoyed by a firm depends on the elasticity of the demand curve that it faces. As the elasticity of demand increases, i.e., as the demand curve becomes flatter, the inverse of the elasticity approaches zero and the monopoly power of the firm decreases. Thus, if the firm’s demand curve has any elasticity less than infinity, the firm has some monopoly power.5. The firm’s exploitation of its monopoly power depends on how easy it is for other firms to enter the industry. There are several barriers to entry, including exclusive rights (e.g., patents, copyrights, and licenses) and economies of scale. These two barriers to entry are the most common. Exclusive rights are legally granted property rights to produce or distribute a good or service. Positive economies of scale lead to “natural monopolies” because the largest producer can charge a lower price, driving competition from the market. For example, in the production of aluminum, there is evidence to suggest that there are scale economies in the conversion of bauxite to alumina. (See U.S. v. Aluminum Company of America , 148 F.2d 416 [1945], discussed in Exercise 7, below.)6. Three factors determine the firm’s elasticity of demand: (1) the elasticity of market demand, (2) the number of firms in the market, and (3) interaction among the firms in the market. The elasticity of market demand dependson the uniqueness of the product, i.e., how easy it is for consumers to substitute away from the product. As the number of firms in the market increases, the demand elasticity facing each firm increases because customers may shift to the fir m’s competitors. The number of firms in the market is determined by how easy it is to enter the industry (the height of barriers to entry). Finally, the ability to raise the price above marginal cost depends on how other firms react to the firm’s price c hanges. If other firms match price changes, customers will have little incentive to switch to another supplier.7. When the firm exploits its monopoly power to raise the price above marginal cost, consumers buy less at the higher price. Consumers enjoy less surplus, the difference between the price they are willing to pay and the market price on each unit consumed. Some of the lost consumer surplus is not captured by the seller and is a deadweight loss to society. Therefore, if the gains to producers were redistributed to consumers, society would still suffer the deadweight loss.8. By restricting price below the monopolist’s profit-maximizing price, the government can change the shape of the firm’s marginal revenue, MR, curve. When a price ceiling is imposed, MR is equal to the price ceiling for all quantities lower than the quantity demanded at the price ceiling. If the government wants to maximize output, it should set a price equal to marginal cost. Prices below this level induce the firm to decrease production, assuming the marginal cost curve is upward sloping. The regulator’s problem is to determine the shape of the monopolist’s marginal cost curve. This task is difficult given the monopolist’s incentive to hide or distort this information.9. The marginal expenditure is the change in the total expenditure as the purchased quantity changes. For a firm competing with many firms for inputs, the marginal expenditure is equal to the average expenditure (price). For a monopsonist, the marginal expenditure curve lies above the average expenditure curve because the decision to buy an extra unit raises the price that must be paid for all units, including the last unit. All firms should buy inputs so that the marginal value of the last unit is equal to the marginal expenditure on that unit. This is true for both the competitive buyer and the monopsonist. However, because the monopsonist’s marginal expenditure curve lies above the average expenditure curve and because the marginal value curve is downward sloping, the monopsonist buys less than a firm would buy in a competitive market.10. Monopsony power is the power in the factor market held by the buyer. A buyer facing an upward-sloping factor supply curve has some monopsony power. In a competitive market, the seller faces a perfectly-elastic market curve and the buyer faces a perfectly-elastic supply curve. Thus, any characteristic of the market (e.g., when there is a small number of buyers or if buyers engage in collusive behavior) that leads to a less-than-perfectly-elastic supply curve gives the buyer some monopsony power.11. The individual firm’s monopsony power depends on the characteristics of the “buying-side” of the market. There are three characteristics that enhance monopsony power: (1) the elasticity of market supply, (2) the number of buyers, and (3) how the buyers interact. The elasticity of market supply depends on how responsive producers are to changes in price. If, in the short run, supply is relatively fixed, then supply is relatively inelastic. For example, since tobacco farmers can sell their crop to only a handful of tobacco product producers, the power to buy at a price below marginal value is increased.12. With monopsony power, the price is lower and the quantity is less than under competitive buying conditions. Because of the lower price and reduced sales, sellers lose revenue. Only part of this lost revenue is transferred to the buyer as consumer surplus, and the net loss in total surplus is deadweight loss. Even if the consumer surplus could be redistributed to sellers, the deadweight loss persists. This inefficiency will remain because quantity is reduced below a level where price is equal to marginal cost.13. Antitrust laws, which are subject to interpretation by the courts, limit market power by proscribing a firm’s behavior in attempting to maximize profit. Section 1 of the Sherman Act prohibits every restraint of trade, including any attempt to fix prices by buyers or sellers. Section 2 of the Sherman Act prohibits behavior that leads to monopolization. The Clayton Act, with the Robinson-Patman Act, prohibits price discrimination and exclusive dealing (sellers prohibiting buyers from buying goods from other sellers). The Clayton Act also limits mergers when they could substantially lessen competition. The Federal Trade Commission Act makes it illegal to use unfair or deceptive practices.14. Antitrust laws are enforced in three ways: (1) through the Antitrust Division of the Justice Department, whenever firms violate federal statutes, (2) through the Federal Trade Commission, whenever firms violate the Federal Trade Commission Act, and (3) through civil suits. The Justice Department can seek to impose fines or jail terms on managers or owners involved or seek to reorganize the firm, as it did in its case against A.T.& T. The FTC can seek a voluntary understanding to comply with the law or a formal Commission order. Individuals or companies can sue in federal court for awards equal to three times the damage arising from the anti-competitive behavior.1. As illustrated in Figure 10.4b in the textbook, an increase in demand need not always result in a higher price. Under the conditions portrayed in Figure 10.4b, the monopolist supplies different quantities at the same price. Similarly, an increase in supply facing the monopsonist need not always result in a higher price. Suppose theaverage expenditure curve shifts from AE 1 to AE 2, as illustrated in Figure 10.1. With the shift in the average expenditure curve, the marginal expenditure curve shifts from ME 1 to ME 2. The ME 1 curve intersects the marginal value curve (demand curve) at Q 1, resulting in a price of P . When the AE curve shifts, the ME 2 curve intersects the marginal value curve at Q 2 resulting in the same price at P .Figure 10.12. As a large producer of farm equipment, Caterpillar Tractor has market power and should consider the entire demand curve when choosing prices for its products. As their advisor, you should focus on the determination of the elasticity of demand for each product. There are three important factors to be considered. First, how similar are the products offered by Caterpillar’s competitors? If they are close substitutes, a small incr ease in price could induce customers to switch to the competition. Secondly, what is the age of the existing stock of tractors? With an older population of tractors, a 5 percent price increase induces a smaller drop in demand. Finally, because farm tractors are a capital input in agricultural production, what is the expected profitability of the agricultural sector? If farm incomes are expected to fall, an increase in tractor prices induces a greater decline in demand than one would estimate with information on only past sales and prices.3. Yes. The monopolist’s pricing rule as a function of the elasticity of demand for its product is:(P -MC)P = - 1E dor alternatively,d E 1 + 1MC= P ⎪⎪⎪⎭⎫ ⎝⎛⎪⎪⎪⎭⎫ ⎝⎛In this example E d = -2.0, so 1/E d = -1/2; price should then be set so that:2MC = 21MC = P ⎪⎪⎭⎫ ⎝⎛ Therefore, if MC rises by 25 percent price, then price will also rise by 25 percent. When MC = $20, P = $40. When MC rises to $20(1.25) = $25, the price rises to $50, a 25% increase.4. a. The profit-maximizing output is found by setting marginal revenue equal to marginal cost. Given a linear demand curve in inverse form, P = 100 - 0.01Q , we know that the marginal revenue curve will have twice the slope of the demand curve. Thus, the marginal revenue curve for the firm is MR = 100 - 0.02Q . Marginal cost is simply the slope of the total cost curve. The slope of TC = 30,000 + 50Q is 50. So MC equals 50. Setting MR = MC to determine the profit-maximizing quantity:100 - 0.02Q = 50, orQ = 2,500.Substituting the profit-maximizing quantity into the inverse demand function to determine theprice:P = 100 - (0.01)(2,500) = 75 cents.Profit equals total revenue minus total cost:π = (75)(2,500) - (30,000 + (50)(2,500)), orπ = $325 per week.b.Suppose initially that the consumers must pay the tax to the government. Since the total price (including the tax) consumers would be willing to pay remains unchanged, we know that the demand function isP* + T = 100 - 0.01Q, orP* = 100 - 0.01Q - T,where P* is the price received by the suppliers. Because the tax increases the price of each unit, total revenue for the monopolist decreases by TQ, and marginal revenue, the revenue on each additional unit, decreases by T:MR = 100 - 0.02Q - Twhere T = 10 cents. To determine the profit-maximizing level of output with the tax, equate marginal revenue with marginal cost:100 - 0.02Q - 10 = 50, orQ = 2,000 units.Substituting Q into the demand function to determine price:P* = 100 - (0.01)(2,000) - 10 = 70 cents.Profit is total revenue minus total cost:()()()()()000,100000,30000,250000,270=+-=πcents, or$100 per week.Note: The price facing the consumer after the imposition of the tax is 80 cents. The monopolist receives 70 cents. Therefore, the consumer and the monopolist each pay 5 cents of the tax.If the monopolist had to pay the tax instead of the consumer, we would arrive at the same result. The monopolist’s cost function would then beTC = 50Q + 30,000 + TQ = (50 + T)Q + 30,000.The slope of the cost function is (50 + T), so MC = 50 + T. We set this MC to the marginal revenue function from part (a):100 - 0.02Q = 50 +10, orQ = 2,000.Thus, it does not matter who sends the tax payment to the government. The burden of the tax is reflected in the price of the good.5. a.To find the marginal revenue curve, we first derive the inverse demand curve. The intercept of the inverse demand curve on the price axis is 27. The slope of the inverse demand curve is the change in price divided by the change in quantity. For example, a decrease in price from 27 to 24 yields an increase in quantity from 0 to 2.Therefore, the slope is -32and the demand curve isP Q=-2715..The marginal revenue curve corresponding to a linear demand curve is a line with the same intercept as the inverse demand curve and a slope that is twice as steep. Therefore, the marginal revenue curve isMR = 27 - 3Q.b.The monopolist’s maximizing output occurs where marginal revenue equals marginal cost. Marginal cost is a constant $10. Setting MR equal to MC to determine the profit-maximizing quantity:27 - 3Q = 10, or Q=567..To find the profit-maximizing price, substitute this quantity into the demand equation:()().5.18$67.55.127=-=PTotal revenue is price times quantity:()().83.104$67.55.18==TRThe profit of the firm is total revenue minus total cost, and total cost is equal to average cost times the level of output produced. Since marginal cost is constant, average variable cost is equal to marginal cost. Ignoring any fixed costs, total cost is 10Q or 56.67, and profit is10483566717..$48..-=c.For a competitive industry, price would equal marginal cost at equilibrium. Setting the expression for priceequal to a marginal cost of 10:271510-=.Q , or Q =1133..Note the increase in the equilibrium quantity compared to the monopoly solution.d.The social gain arises from the elimination of deadweight loss. Since deadweight loss under monopoly is equal to the difference between the price under monopoly minus the price under competition (18.5 - 10 = 8.5) times the difference between the quantity under competition minus the quantity under monopoly (11.3 - 5.67 = 5.67) times one-half, the deadweight loss is a triangle under the demand curve:(0.5)(8.5)(5.67) = $24.10.Furthermore, consumers gain this deadweight loss plus the monopolist’s profit of $48. The monopolist’s profits are reduced to zero, and the consumer surplus increases by $72.6. a. The average revenue curve is the demand curve,P = 700 - 5Q .For a linear demand curve, the marginal revenue curve has the same intercept as the demand curve and a slope that is twice as steep:MR = 700 - 10Q .Next, determine the marginal cost of producing Q . To find the marginal cost of production in Factory 1, take the first derivative of the cost function with respect to Q :().20111Q dQQ dC = Similarly, the marginal cost in Factory 2 is().40222Q dQQ dC = Rearranging the marginal cost equations in inverse form and horizontally summing them, we obtain total marginal cost, MC T :Q Q Q MC MC MC T =+=+=12122040340, orMC Q T =403. Profit maximization occurs where MC T = MR . See the Figure 10.6.a for the profit-maximizing output for each factory, total output, and price.Figure 10.6.ab.Calculate the total output that maximizes profit, i.e., Q such that MC T = MR :40370010Q Q =-, or Q = 30. Next, observe the relationship between MC and MR for multiplant monopolies:MR = MC T = MC 1 = MC 2.We know that at Q = 30, MR = 700 - (10)(30) = 400.Therefore,MC 1 = 400 = 20Q 1, or Q 1 = 20 andMC 2 = 400 = 40Q 2, or Q 2 = 10.To find the monopoly price, P M , substitute for Q in the demand equation:This means that the demand curve becomes P = 20 - 3Q 2. With an inverse linear demand curve, we know that the marginal revenue curve has the same vertical intercept but twice the slope, or MR = 20 - 6Q 2. To determine the profit-maximizing level of output, equate MR and MC 2:20 - 6Q 2 = 10 + 5Q 2, orQ Q ==2091..Price is determined by substituting the profit-maximizing quantity into the demand equation:()3.1791.0320=-=P .8. a. Although Alcoa controlled about 90 percent of primary aluminum production in the United States, secondary aluminum production by recyclers accounted for 30 percent of the total aluminum supply. Therefore, with a higher price, a much larger proportion of aluminum supply could come from secondary sources. This assertion is true because there is a large stock of potential supply in the economy. Therefore, the price elasticity of demand for Alcoa’s primary aluminum is much higher than we would expect, given Alcoa’s domi nant position in primary aluminum production. In many applications, other metals such as copper and steel are feasible substitutes for aluminum. Again, the demand elasticity Alcoa faces might be lower than we would otherwise expect.b.While Alcoa could not raise its price by very much at any one time, the stock of potential aluminum supply is limited. Therefore, by keeping a stable high price, Alcoa could reap monopoly profits. Also, since Alcoa had originally produced the metal reappearing as recycled scrap, it would have considered the effect of scrap reclamation on future prices. Therefore, it exerted effective monopolistic control over the secondary metal supply.c.Judge Hand ruled against Alcoa but did not order it to divest itself of any of its United States production facilities. The two remedies imposed by the court were (1) that Alcoa was barred from bidding for two primary aluminum plants constructed by the government during World War II (they were sold to Reynolds and Kaiser) and (2) that it divest itself of its Canadian subsidiary, which became Alcan.9. a. Because demand (average revenue) may be described as P = 11 - Q , we know that the marginal revenue function is MR = 11 - 2Q . We also know that if average cost is constant, then marginal cost is constant and equal to average cost: MC = 6.To find the profit-maximizing level of output, set marginal revenue equal to marginal cost:11 - 2Q = 6, or Q = 2.5.That is, the profit-maximizing quantity equals 2,500 units. Substitute the profit-maximizingquantity into the demand equation to determine the price:P = 11 - 2.5 = $8.50.Profits are equal to total revenue minus total cost,π = TR - TC = (AR )(Q ) - (AC )(Q ), orπ = (8.5)(2.5) - (6)(2.5) = 6.25, or $6,250. The degree of monopoly power is given by the Lerner Index:P MC-=-=8560294... b.To determine the effect of the price ceiling on the quantity produced, substitute the ceiling price into the demandequation.7 = 11 - Q , orQ = 4,000.This quantity is the profit-maximizing level of output for the monopolist because, at that level,MR = MC .Profits are equal to total revenue minus total cost:π = (7)(4,000) - (6)(4,000) = $4,000. The degree of monopoly power is:P MC -=-=760143.. c.If the regulatory authority sets a price below $6, the monopolist would prefer to go out of business instead of produce because it cannot cover its average costs. At any price above $6, the monopolist would produce less than the 5,000 units that would be produced in a competitive industry. Therefore, the regulatory agency should set a price ceiling of $6, thus making the monopolist face a horizontal effective demand curve up to Q = 5,000. To ensure a positive output (so that the monopolist is not indifferent between producing 5,000 units and shutting down), the price ceiling should be set at $6 + δ, where δ is small.Thus, 5,000 is the maximum output that the regulatory agency can extract from the monopolistby using a price ceiling. The degree of monopoly power isP MC P -=+-=→66660δδ as δ → 0. 10.a. M MMT should offer enough t-shirts such that MR = MC . In the short run, marginal cost is the change in SRTC as the result of the production of another t-shirt, i.e.,SRMC = 5, the slope of the SRTC curve. Demand is:Q P =100002,, or, in inverse form,P = 100Q-1/2. Total revenue (PQ ) is 100Q 1/2. Taking the derivative of TR with respect to Q , MR = 50Q -1/2. Equating MR and MC to determine the profit-maximizing quantity:5 = 50Q -1/2, or Q = 100.Substituting Q = 100 into the demand function to determine price:P = (100)(100-1/2 ) = 10.The profit at this price and quantity is equal to total revenue minus total cost:π = (10)(100) - (2000 + (5)(100)) = -$1,500.Although profit is negative, price is above the average variable cost of 5 and therefore, the firm should not shut down in the short run. Since most of the firm’s costs are fixed, the firm loses $2,000 if nothing is produced. If the profit-maximizing quantity is produced, the firm loses only $1,500.b.In the long run, marginal cost is equal to the slope of the LRTC curve, which is 6.Equating marginal revenue and long run marginal cost to determine the profit-maximizing quantity:50Q -1/2 = 6 or Q = 69.44Substituting Q = 69.44 into the demand equation to determine price:P = (100)[(50/6)2] -1/2 = (100)(6/50) = 12Therefore, total revenue is $833.33 and total cost is $416.67. Profit is $416.67. The firm should remain in business.c.In the long run, MMMT must replace all fixed factors. Therefore, we can expect LRMC to be higher than SRMC .11. No, production should not shift to the Massachusetts plant, although production in the Connecticut plant should be reduced. In order to maximize profits, a mulitplant firm will schedule production at all plants so that the following two conditions are met:- Marginal costs of production at each plant are equal.- Marginal revenue of the total amount produced is equal to the marginal cost at each plant.These two rules can be summarized as MR = MC1 = MC2= MC3, where the subscript indicates the plant.The firm in this example has two plants and is in a perfectly competitive market. In a perfectly competitive market P = MR. To maximize profits, production among the plants should be allocated such that:(10,000)(n), and marginal expenditure is 10,000. Equating marginal value and marginal expenditure:30,000 - 125n = 10,000, orn = 160.13. a. To maximize profits, DD should equate marginal revenue and marginal cost. Given a demand of P = 55 - 2Q, we know that total revenue, PQ, is 55Q - 2Q2. Marginal revenue is found by taking the first derivative of total revenue with respect to Q or:MRdTRdQQ ==-554.Similarly, marginal cost is determined by taking the first derivative of the total cost function with respect to Q or:MCdTCdQQ==-2 5.Equating MC and MR to determine the profit-maximizing quantity,55 - 4Q = 2Q - 5, orQ = 10.Substituting Q = 10 into the demand equation to determine the profit-maximizing price:P = 55 - (2)(10) = $35.Profits are equal to total revenue minus total cost:π = (35)(10) - (100 - (5)(10) + 102) = $200.Consumer surplus is equal to one-half times the profit-maximizing quantity, 10, times thedifference between the demand intercept (the maximum price anyone is willing to pay) and themonopoly price:CS = (0.5)(10)(55 - 35) = $100.b.In competition, profits are maximized at the point where price equals marginal cost, where price is givenby the demand curve:55 - 2Q = -5 + 2Q, orQ = 15.Consumer surplus isCS = (0.5)(55 - 27)(14) = $196.Profits areπ = (27)(14) - (100 - (5)(14) + 142) = $152.The deadweight loss is $2.00 This is equivalent to a triangle of(0.5)(15 - 14)(27 - 23) = $2e.With a ceiling price set below the competitive price, DD will decrease its output. Equate marginal revenue and marginal cost to determine the profit-maximizing level of output:23 = - 5 + 2Q, or Q = 14.With the government-imposed maximum price of $23, profits areπ = (23)(14) - (100 - (5)(14) + 142) = $96.Consumer surplus is realized on only 14 doorsteps. Therefore, it is equal to the consumersurplus in part d., i.e. $196, plus the savings on each doorstep, i.e.,CS = (27 - 23)(14) = $56.Therefore, consumer surplus is $252. Deadweight loss is the same as before, $2.00.f.With a maximum price of only $12, output decreases even further:12 = -5 + 2Q, or Q = 8.5.Profits areπ = (12)(8.5) - (100 - (5)(8.5) + 8.52) = -$27.75.Consumer surplus is realized on only 8.5 units, which is equivalent to the consumer surplusassociated with a price of $38 (38 = 55 - 2(8.5)), i.e.,(0.5)(55 - 38)(8.5) = $72.25plus the savings on each doorstep, i.e.,(38 - 12)(8.5) = $221.Therefore, consumer surplus is $293.25. Total surplus is $265.50, and deadweight loss is $84.50.11。
平狄克微观经济学答案——第10章卖方垄断与买方垄断
第三部分 企业结构 第十章 市场势力：卖方垄断与买方垄断
教学注解 这一章同时涵盖了卖方垄断与买方垄断两部分，旨在揭示两种类型市场势 力的相似性。本章开始的 1－4 节讨论的是卖方垄断。第 5 节首先讨论买方垄断， 然后提出卖方垄断与买方垄断的指导性比较。第 6 节讨论买方势力的来源及其 社会成本。第 7 节以对反垄断法的讨论终结本章。如果时间较紧，你可以只讲 述有关卖方垄断的前 4 节而略去本章其余部分。你可以讲述第 7 节即便略去了 5、6 节。第 1 节最后有关复合企业的部分同样可以略去。 尽管第 8 章讲述了利润最大化的一般规则，你应当通过对方程 10.1 的推导 复习边际收入及供给的价格弹性。对方程 10.1 推导的讨论有助于说明图形 10.3 的几何意义。指出对于买方垄断者而言，由于利润最大化处的价格及产量所对 应的边际收入为正，该产量处的弹性较大。同时，方程 10.1 直接引出了 10.2 节 的勒纳指数。这为卖方垄断市场势力的讨论奠定了坚实的基础。比如说，如果 Ed 较大（如由于高度替代品），那么，（1）需求曲线相对平坦，（2）边际收入 曲线相对平坦（尽管比需求曲线陡峭），（3）卖方垄断者难以使价格超出边际成 本很多。为了强调这一点，可以引入非线性需求曲线，比如，展示单位弹性需 求曲线的边际收入曲线的位置。一旦这些概念讲清楚了，对于面对非线性需求 曲线的卖方垄断厂商征税效果的讨论就不是那么困难了。 市场势力的社会成本是课堂讨论的较好话题。对于卖方垄断造成的无谓损 失可以与第 9 章的市场干预分析加以比较引出。比如将图 10.10 与图 9.5 进行比 较。考虑到练习（9），（13），（15）涉及了“拐折的边际收入曲线”，如果你要 布置这些作业，你应当讲解图 10.11。尽管图 10.11 很复杂，在这里涉及有助于 12 章重现时的理解。
平狄克《微观经济学》(第9版)笔记和课后习题详解
平狄克《微观经济学》（第9版）笔记和课后习题详解第1篇导论：市场与价格
第1章绪论
1.1 复习笔记
【知识框架】
【考点难点归纳】
考点一：微观经济学的主题（见表1-1）★
表1-1 微观经济学的主题
考点二：微观经济学的分析方法——实证分析和规范分析（见表1-2）★★
表1-2 微观经济学的分析方法——实证分析和规范分析
考点三：市场★
市场是指买者和卖者的集合，以及由此确定的潜在的买卖。
微观经济学中的市场不仅有买方和卖方都不会影响市场的竞争性市场，还有卖方影响市场的非竞争市场，如寡头市场、垄断竞争市场等。
市场是有范围的，不仅要考虑地理边界，还要考虑包含产品范围的大小。
如住房市场是高度当地化的，而黄金市场却是世界性的。
市场的价格是在买卖双方互动的基础上形成的。
一般而言，微观经济学考察市场均衡的价格，即一个市场上的供给等于需求时的价格。
考点四：名义价格与实际价格★★
1名义价格与实际价格的含义
名义价格是指以某些货币表示的，未经过通货膨胀的调整的价格。
实际价格则是指名义价格剔除通货膨胀因素之后的价格。
2名义价格与实际价格的关系
名义价格与实际价格的关系需要引入消费价格指数（CPI）。
居民消费价格指数是一个反映居民家庭一般所购买的消费品和服务项目价格水平变动情况的宏观经济指标，它是衡量通货膨胀的主要指标之一。
某年商品的实际价格与名义价格之间的关系为：
某年商品的实际价格＝基准年消费物价指数/计算年消费物价指数×计算年的名义价格。
平狄克《微观经济学》课后答案 3-4
CHAPTER 3CONSUMER BEHAVIORChapter 3 builds the foundation to derive the demand curve in Chapter 4. In order to understand demand theory, students must have a firm grasp of indifference curves, the marginal rate of substitution, the budget line, and optimal consumer choice. Utility theory may be discussed independently from consumer choice. Many students find utility functions to be a more abstract concept than preference relationships. However, if you plan to discuss uncertainty in Chapter 5, you will need to cover marginal utility. Even if you cover utility theory only briefly, make sure students are comfortable with the term utility because it appears frequently in Chapter 4.When introducing indifference curves, stress that physical quantities are represented on the two axes. After discussing supply and demand, students may think that price should be on the vertical axis. To develop indifference curves, start with any point in the Cartesian plane and ask for points that are more (and less) preferred. This will divide the plane into four quadrants. Then ask between which points they will be indifferent. Once students grasp the concept of preference points, introduce the notion of a “preference hill.” Using the example of a topographical map or a well-drawn three dimensional figure, point out that a three-dimensional figure is being collapsed into two dimensions.The marginal rate of substitution, MRS , is confusing to students. Some confuse the MRS with the ratio of the two quantities. If this is the case, point out that the slope is equal to the ratio of the rise, ∆Y, and the run, ∆X . This ratio is equal to the ratio of the intercepts of a line just tangent to the indifference curve. As we move along a convex indifference curve, these intercepts and the MRS change. Another problem is the terminology “of X for Y .” This is confusing because we are not substituting “X for Y ,” but Y for one unit of X . Exercise (6) discusses this point, but you may want to offer other exercises to stress it.1. What does transitivity of preferences mean?Transitivity of preferences implies that if someone prefers A to B and prefers B to C , then he orshe prefers A to C .satisfaction. This trading continues until the highest level of satisfaction is achieved.6. Explain why consumers are likely to be worse off when a product that they consume is rationed.If the maximum quantity of a good is fixed by decree and desired quantities are not available forpurchase, then there is no guarantee that the highest level of satisfaction can be achieved. Theconsumer will not be able to give up the consumption of other goods in order to obtain more of therationed good. Only if the amount rationed is greater than the desired level of consumption canthe consumer still maximize satisfaction without constraint. (Note: rationing may imply ahigher level of social welfare because of equity or fairness considerations across consumers.)7. Upon merging with West Germany’s economy, East German consumers indicated a preference for Mercedes-Benz automobiles over Volkswagen automobiles. However, when they converted their savings into deutsche marks, they flocked to Volkswagen dealerships. How can you explain this apparent paradox?Three assumptions are required to address this question: 1) that a Mercedes costs more than aVolkswagen; 2) that the East German consumers’ utility function comprises two goods,automobiles and all other goods evaluated in deutsche marks; and 3) that East Germans haveincomes. Based on these assumptions, we can surmise that while once-East German consumersmay prefer a Mercedes to a Volkswagen, they either cannot afford a Mercedes or they prefer abundle of other goods plus a Volkswagen to a Mercedes alone.8. Describe the equal marginal principle. Explain why this principle may not hold if increasing marginal utility is associated with the consumption of one or both goods.The equal marginal principle states that the ratio of the marginal utility to price must be equalacross all goods to obtain maximum satisfaction. This explanation follows from the same logicexamined in Review Question 5. Utility maximization is achieved when the budget is allocatedso that the marginal utility per dollar of expenditure is the same for each good.If marginal utility is increasing, the consumer maximizes satisfaction by consuming ever largeramounts of the good. Thus, the consumer would spend all income on one good, assuming aconstant price, resulting in a corner solution. With a corner solution, the equal marginalprinciple cannot hold.9. What is the difference between ordinal utility and cardinal utility? Explain why the assumption of cardinal utility is not needed in order to rank consumer choices.Ordinal utility implies an ordering among alternatives without regard for intensity of preference.For example, the consumer’s first choice is preferred to their second choice. Cardinal utilityimplies that the intensity of preferences may be quantified. An ordinal ranking is all that isneeded to rank consumer choices. It is not necessary to know how intensely a consumer prefersbasket A over basket B; it is enough to know that A is preferred to B.10. The price of computers has fallen substantially over the past two decades. Use this drop in price to explain why the Consumer Price Index is likely to substantially understate the cost-of-living index for individuals who use computers intensively.The consumer price index measures the changes in the weighted average of the prices of thebundle of goods purchased by consumers. The weights equal the share of consumer's expenditureson all of the goods in the bundle. A base year is chosen, and the weights for that year are used tocompute the CPI in that and subsequent years. When the price of a good falls substantially then aconsumer will substitute towards that good, altering the share of that consumer's income spent oneach good. By using the base year's weights the CPI does not take into account that large pricechanges alter these expenditure shares, and so gives an inaccurate measure of changes in the costof living.For example, assume Fred spends 10% of his income on computers in 1970, and that Fred'sexpenditure shares in 1970 were used as the weights to calculate Fred's CPI in subsequent years.If Fred's demand for computers was inelastic, then reductions in the price of computers (relativeto other goods) would reduce the share of his income spent on computers. After 1970 a CPI thatused Fred's 1970 expenditure shares as weights would give a 10% weight to the falling price ofcomputers, even though Fred spent less that 10% of his income on computers. So long as theprices of other goods rose, or fell less than 10%, then the CPI gives too little weight to the changesin the prices of other goods, and understates the changes in Fred's cost of living.1. In this chapter, consumer preferences for various commodities did not change during the analysis. Yet in some situations, preferences do change as consumption occurs. Discuss why and how preferences might change over time with consumption of these two commodities:a. cigarettesThe assumption that preferences do not change is a reasonable one if choices are independentacross time. It does not hold, however, when “habit-forming” or addictive behavior is involved, asin the case of cigarettes: the consumption of cigarettes in one period influences their consumptionin the next period.b. dinner for the first time at a restaurant with a special cuisineWhile there may not be anything physically addictive in dining at new and different restaurants, one can become better informed about a particular restaurant. One may enjoy choosing more new and different restaurants, or one may be tired of choosing another new and different place to4.a.c. tothis graphically?, the quantity of butter by B, the Let Bill’s income be represented by Y, the price of butter by PB, and the quantity of margarine by M. Then the general form of the price of margarine by PMbudget constraint is:5.the their a.c. If both Smith and Jones pay the same prices for their refreshments, will their marginal rates ofsubstitution of alcoholic for nonalcoholic drinks be the same or different? Explain.In order to maximize utility, the consumer must consume quantities such that the MRS betweenany two commodities is equal to the ratio of prices. If Smith and Jones are rational consumers,their MRS must be equal because they face the same market prices. But because they havedifferent preferences, they will consume different amounts of the two goods, alcoholic andnonalcoholic. At those different levels, however, their MRS are equal.6. Anne is a frequent flyer whose fares are reduced (through coupon giveaways) by 25 percent after she flies 25,000 miles a year, and then by 50 percent after she flies 50,000 miles. Can you graph the budget line that Anne faces in making her flight plans for the year?In Figure 3.6, we plot miles flown, M , against all other goods, G , in dollars. The budgetconstraint is:Y = P M M + P G G , or.⎪⎪⎭⎫ ⎝⎛-=G M G P P M P Y G The slope of the budget line is -P P M G. In this case, the price of miles flown changes as the number of miles flown changes, so the budget curve is kinked at 25,000 and at 50,000 miles. Suppose P M is $1 per mile for less than or equal to 25,000 miles. Then P M = $0.75 for 25,000 < M ≥ 50,000 and P M = $0.50 for M > 50,000. Also, let P G = $1.00. Then the slope of the budget line from A to B is -1, the slope of the budget line from B to C is -0.75, and the slope of the budget line from B to D is -0.5.8. Suppose that Samantha and Jason both spend $24 per week on video and movie entertainment.U = 12 U = 24Food Clothing Food Clothing 1.0 12.0 1.0 24.01.5 8.02.0 12.02.0 6.03.0 8.012 = 1F + 3C , or ⎪⎪⎭⎝-=34.See Figure 3.10.a.c. What is the utility-maximizing choice of food and clothing? (Hint: Solve the problemgraphically.)The highest level of satisfaction occurs where the budget line is tangent to the highestindifference curve. In Figure 3.10.a this is at the point F = 6 and C = 2. To check this answer,note that it exhausts Jane’s income, 12 = 6P F + 2P C . Also, this bundle yields a satisfaction of 12,as (6)(2) = 12. See Figure 3.10.a.d. What is the marginal rate of substitution of food for clothing when utility is maximized?At the utility-maximizing level of consumption, the slope of the indifference curve is equal to theslope of the budget constraint. Since the MRS is equal to the negative slope of the indifferencecurve, the MRS in this problem is equal to one-third. Thus, Jane would be willing to give upone-third of a unit of clothing for one unit of food.e. Suppose that Jane buys 3 units of food and 3 units of clothing with her $12 budget. Would hermarginal rate of substitution of food for clothing be greater or less than 1/3? Explain.If Jane buys 3 units of food for $1.00 per unit and 3 units of clothing for $3.00 per unit, she wouldspend all her income. However, she would obtain a level of satisfaction of only 9, whichrepresents a sub-optimal choice. At this point, the MRS is greater than one-third, and thus, atthe prices she faces, she would welcome the opportunity to give up clothing to get more food. Sheis willing to trade clothing for food until her MRS is equal to the ratio of prices. See Figure3.10.c.Figure 3.10.c11. The utility that Meredith receives by consuming food F and clothing C is given by u(F,C) = FC. Suppose that Meredith’s income in 1990 is $1,200 and the prices of food and clothing are $1 per unit for each. However, by 1995 the price of food has increased to $2 and the price of clothing to $3. Let 100 represent the cost of living index for 1990. Calculate the ideal and the Laspeyres cost-of-living index for Meredith for 1995. (Hint: Meredith will spend equal amounts on food and clothing with these preferences.)Laspeyres IndexThe Laspeyres index represents how much more Meredith would have to spend in 1995 versus 1990 ifshe consumed the same amounts of food and clothing in 1995 as she did in 1990. That is, the Laspeyresindex for 1995 (L) is given by:L = 100 (Y ')/Ywhere Y’ represents the amount Meredith would spend at 1995 prices consuming the same amount offood and clothing as in 1990: Y ' = P 'F F + P 'C C = 2F + 3C, where F and C represent the amounts of foodand clothing consumed in 1990.We thus need to calculate F and C, which make up the bundle of food and clothing which maximizesMeredith’s utility given 1990 prices and her income in 1990. Use the hint to simplify the problem:Since she spends equal amounts on both goods, P F F = P C C. Or, you can derive this same equationmathematically: With this utility function, MU C = ∆U/∆C = F, and MU F = ∆U/∆F = C. To maximizeutility, Meredith chooses a consumption bundle such that MU F /MU C = P F /P C , which again yields P F F =P C C.From the budget constraint, we also know that:P F F +P C C = YCombining these two equations and substituting the values for the 1990 prices and income yields thesystem of equations:C = F and C + F = 1,200Solving these two equations, we find that:C = 600 and F = 600Therefore, the Laspeyres cost-of-living index is:L = 100(2F + 3C)/Y = 100[(2)(600) + (3)(600)]/1200 = 250Ideal IndexThe ideal index represents how much more Meredith would have to spend in 1995 versus 1990 if sheconsumed amounts of food and clothing in 1995 which would give her the same amount of utility as shehad in 1990. That is, the ideal index for 1995 (I) is given by:I = 100(Y'')/Y, where Y'' = P'F F + P'C C' = 2F' + 3C'where F' and C' are the amount of food and clothing which give Meredith the same utility as she had in1990. F' and C' must also be such that Meredith spends the least amount of money at 1995 prices toattain the 1990 utility level.The bundle (F',C') will be on the same indifference curve as (F,C) and the indifference curve at this point will be tangent to a budget line with slope -(P'F /P'C ), where P'F and P'C are the prices of food and clothing in 1995. Since Meredith spends equal amounts on the two goods, we know that 2F' = 3C'. Since this bundle lies on the same indifference curve as the bundle F = 600, C = 600, we also know that F'C' = (600)(600).Cslope 1P slope F C =-H K slope slope F C =-'H KFigure 3.11Solving for F' yields:F'[(2/3)F'] = 360,000 or F' =[(/),)]32360000 = 734.8From this, we obtain C':C' = (2/3)F' = (2/3)734.8 = 489.9We can now calculate the ideal index: I = 100(2F' + 3C')/Y = 100[2(734.8) + (3)(489.9)]/1200 = 244.9CHAPTER 4INDIVIDUAL AND MARKET DEMANDChapter 4 relies on two important ideas from Chapter 3: the influence of price and income changes on the budget line and optimal consumer choice. The chapter focuses on price changes, individual demand, market demand, demand elasticity, and consumer surplus. These concepts are crucial to understanding the application of demand and supply analysis in Chapter 9 as well as the discussion of market failure in Parts III and IV. Chapter 4 also discusses the derivation of the individual’s demand curve with a discussion of substitution and income effects. The analytical tools students learn in this chapter will be important for the discussion of factor supply and demand in Chapter 14.When discussing the derivation of demand, review how the budget curve pivots around an intercept as price changes and how optimal quantities change as the budget line pivots. Once students understand the effect of price changes on consumer choice, they can grasp the derivation of the price consumption path and the individual demand curve. Remind students that the price a consumer is willing to pay is a measure of the marginal benefit of consuming another unit.When covering the aggregation of individual demands, stress that this is equivalent to the summation of individual demand curves horizontally. Students might think that they can add linear demand functions, e.g., add Q P =-1 plus Q P =-23 to arrive at Q P =-35 or 223Q P =-. Students must be reminded, instead, to write the demand curve in inverse form, with price as a function of quantity, and then add. Thus, we add P = 1 - Q to P = 1 - 2Q to obtain P = 2 - 3Q .Price elasticity of demand and consumer surplus are referred to throughout the text, but the mathematics of price elasticity of demand is difficult for many students. Before discussing the algebra, encourage students to develop an intuitive grasp of elasticity as a measure of the sensitivity of the quantity demanded to changes in price.The easiest algebraic representation of elasticity is %%∆∆QP. As you expand on this expression, make sure thatstudents can distinguish between the slope of a line and an elasticity at each point. One effective teaching method is using a linear demand curve to show that while the slope is constant, the elasticity changes throughout the range of prices. The text relies on this relationship in the discussion of the monopolist’s determination of the profit-maximizing quantity in Chapter 10. The exercises given here are progressive in their difficulty, i.e., the last exercise is much harder than the first. Exercises (1) and (7) assume student understanding of demand elasticity, and a grasp of income elasticity is needed for Exercise (9).Although this chapter introduces consumer surplus, it is not extensively discussed until Chapter 9; producer surplus is covered in Chapter 8. If you postpone the discussion of consumer surplus, do not assign Exercise (4). Once students understand consumer surplus, they will find it to be an extremely useful tool. See Example 4.5.Section 4.2 discusses income and substitution effects. An understanding of these effects is aided by the discussion of normal and inferior goods. This is also a good time to reinforce the concept of relative prices, i.e., a decrease in the price of one good increases the relative price of the other good. Giffen goods, while infrequently encountered, provide a way to discuss the importance of income and substitution effects.Finally, there are other special topics in this chapter and its Appendix. An application of network externalities is given in Example 4.5. The first part of Section 4.6, “Empirical Estimation of Demand,” is straightforward, particularly if you have covered the forecasting section of Chapter 2. However, the l ast part, “The Form of the Demand Relationship,” is difficult for students who do not understand logarithms. The Appendix is intended for students with a background in calculus.1.How is an individual demand curve different from a market demand curve? Which curve is likely to be more price elastic? (Hint: Assume that there are no network externalities.)The market demand curve is the horizontal summation of the individual demand curves. Thegraph of market demand shows the relation between each price and the sum of individualquantities. Because price elasticities of demand may vary by individual, the price elasticity ofdemand is likely to be greater than some individual price elasticities and less than others.2.Is the demand for a particular brand of product, such as Head skis, likely to be more price elastic or price inelastic than the demand for the aggregate of all brands, such as downhill skis? Explain.Individual brands compete with other brands. If the two brands are similar, a small change inthe price of one good will encourage many consumers to switch to the other brand. Becausesubstitutes are readily available, the quantity response to a change in one brand’s price is moreelastic than the quantity response for all brands. Thus, the demand for Head skis is more elasticthan the demand for downhill skis.3.Tickets to a rock concert sell for $10. But at that price, the demand is substantially greater than the available number of tickets. Is the value or marginal benefit of an additional ticket greater than, less than, or equal to $10? How might you determine that value?If, at $10, demand exceeds supply, then consumers are willing to bid up the market price to a levelwhere the quantity demanded is equal to the quantity supplied. Since utility-maximizingconsumers must be willing to pay more than $10, then the marginal increase in satisfaction(value) is greater than $10. One way to determine the value of tickets would be to auction off ablock of tickets. The highest bid would determine the value of the tickets.4.Suppose a person allocates a given budget between two goods, food and clothing. If food is an inferior good, can you tell whether clothing is inferior or normal? Explain.If an individual consumes only food and clothing, then any increase in income must be spent oneither food or clothing (Hint: we assume there are no savings). If food is an inferior good, then,as income increases, consumption falls. With constant prices, the extra income not spent on foodmust be spent on clothing. Therefore, as income increases, more is spent on clothing, i.e. clothingis a normal good.5. Which of the following combinations of goods are complements and which are substitutes? Could they be either in different circumstances? Discuss.a. a mathematics class and an economics classIf the math class and the economics class do not conflict in scheduling, then the classes could beeither complements or substitutes. The math class may illuminate economics, and theeconomics class can motivate mathematics. If the classes conflict, they are substitutes.b. tennis balls and a tennis racketTennis balls and a tennis racket are both needed to play a game of tennis, thus they arecomplements.c. steak and lobsterFoods can both complement and substitute for each other. Steak and lobster can compete, i.e., besubstitutes, when they are listed as separate items on a menu. However, they can also functionas complements because they are often served together.d. a plane trip and a train trip to the same destinationTwo modes of transportation between the same two points are substitutes for one another.e. bacon and eggsBacon and eggs are often eaten together and are, therefore, complementary goods. Byconsidering them in relation to something else, such as pancakes, bacon and eggs can function assubstitutes.6.Which of the following events would cause a movement along the demand curve for U.S.-produced clothing, and which would cause a shift in the demand curve?a. the removal of quotas on the importation of foreign clothesThe removal of quotas will shift the demand curve inward for domestically-produced clothes,because foreign-produced goods are substitutes for domestically-produced goods. Both theequilibrium price and quantity will fall as foreign clothes are traded in a free marketenvironment.b. an increase in the income of U.S. citizensWhen income rises, expenditures on normal goods such as clothing increase, causing the demandcurve to shift out. The equilibrium quantity and price will increase.c. a cut in the industry’s costs of producing domestic clothes that is passed on to the market inthe form of lower clothing pricesA cut in an industry’s costs will shift the supply curve out. The equilibrium price an d quantitywill increase.7. For which of the following goods is a price increase likely to lead to a substantial income (as well as substitution) effect?a. saltSmall income effect, small substitution effect: The amount of income that is spent on salt isrelatively small, but since there are few substitutes for salt, consumers will not readily substituteaway from it. As the price of salt rises, real income will fall only slightly, thus leading to a smalldecline in consumption.b. housingLarge income effect, no substitution effect: The amount of income spent on housing is relativelylarge for most consumers. If the price of housing were to rise, real income would be reducedsubstantially, thereby reducing the consumption of all other goods. However, consumers wouldfind it impossible to substitute for housing, in general.c. theater ticketsSmall income effect, large substitution effect: The amount of income that is spent on theatertickets is relatively small, but consumers can substitute away from the theater tickets by choosingother forms of entertainment (e.g., television and movies). As the price of theater tickets rises,real income will fall only slightly, thus leading to a small decline in consumption.d. foodLarge income effect, no substitution effect: As with housing, the amount of income spent on food isrelatively large for most consumers. Price increases for food will reduce real incomesubstantially, thereby reducing the consumption of all other commodities. Although consumerscan substitute out of particular foods, they cannot substitute out of food in general.8. Suppose that the average household in a state consumes 500 gallons of gasoline per year. A 10-cent gasoline tax is introduced, coupled with a $50 annual tax rebate per household. Will the household be better or worse off after the new program is introduced?If the household does not change its consumption of gasoline, it will be unaffected by thetax-rebate program. It still gets 500 gallons of gasoline. To the extent that the householdreduces its gas consumption through substitution, it must be better off.9. Which of the following three groups is likely to have the most, and which the least, price-elastic demand for membership in the Association of Business Economists?a. studentsThe major difference among the groups is the level of income. We know that if the consumptionof a good constitutes a large percentage of an individual’s income, then the demand for the goodwill be relatively elastic. If we assume that a membership in the Association of BusinessEconomists is likely to be a large expenditure for students, we may conclude that the demand willbe relatively elastic for this group.b. junior executivesThe level of income for junior executives will be larger than that of students, but smaller thanthat of senior executives. Therefore, the demand for a membership for this group will be lesselastic than that of the students but more elastic than that of the senior executives.c. senior executivesThe high earnings among senior executives will result in a relatively inelastic demand formembership.1. The ACME corporation determines that at current prices the demand for its computer chips has a price elasticity of -2 in the short run, while the price elasticity for its disk drives is -1.a. If the corporation decides to raise the price of both products by 10 percent, what will happento its sales? To its sales revenue?We know the formula for the elasticity of demand is:EQP P=%%∆∆.For computer chips, EP= -2, so a 10 percent increase in price will reduce the quantity sold by 20percent. For disk drives, EP= -1, so a 10 percent increase in price will reduce sales by 10 percent.Sales revenue is equal to price times quantity sold. Let TR1 = P1Q1be revenue before the pricechange and TR2 = P2Q2be revenue after the price change.For computer chips:∆TR cc = P2Q2 - P1Q1∆TR cc= (1.1P1 )(0.8Q1 ) - P1Q1 = -0.12P1Q1, or a 12 percent decline.For disk drives:∆TR dd = P2Q2 - P1Q1∆TR dd = (1.1P1 )(0.9Q1 ) - P1Q1 = -0.01P1Q1, or a 1 percent decline.Therefore, sales revenue from computer chips decreases substantially, -12 percent, while the salesrevenue from disk drives is almost unchanged, -1 percent.b. Can you tell from the available information which product will generate the most revenue forthe firm? If yes, why? If not, what additional information would you need?No. Although we know the responsiveness of demand to changes in price, we need to know bothquantities and prices of the products to determine total sales revenue.2. Refer to Example 4.3 on the aggregate demand for wheat. From 1981 to 1990, domestic demand grew in response to growth in U.S. income levels. As a rough approximation, the domestic demand curve in 1990 was QDD= 1200 - 55P. Export demand, however, remained about the same, due to。
平狄克《微观经济学》(第9版)笔记和课后习题详解
平狄克《微观经济学》（第9版）笔记和课后习题详解
来源微♥公号精研学习网
第1篇导论：市场与价格
第1章绪论
1.1复习笔记
【知识框架】
【考点难点归纳】
考点一：微观经济学的主题（见表1-1）★
表1-1微观经济学的主题
考点二：微观经济学的分析方法——实证分析和规范分析（见表1-2）★★
表1-2微观经济学的分析方法——实证分析和规范分析
考点三：市场★
市场是指买者和卖者的集合，以及由此确定的潜在的买卖。
微观经济学中的市场不仅有买方和卖方都不会影响市场的竞争性市场，还有卖方影响市场的非竞争市场，如寡头市场、垄断竞争市场等。
市场是有范围的，不仅要考虑地理边界，还要考虑包含产品范围的大小。
如住房市场是高度当地化的，而黄金市场却是世界性的。
市场的价格是在买卖双方互动的基础上形成的。
一般而言，微观经济学考察市场均衡的价格，即一个市场上的供给等于需求时的价格。
考点四：名义价格与实际价格★★
1名义价格与实际价格的含义
名义价格是指以某些货币表示的，未经过通货膨胀的调整的价格。
实际价格则是指名义价格剔除通货膨胀因素之后的价格。
2名义价格与实际价格的关系
名义价格与实际价格的关系需要引入消费价格指数（CPI）。
居民消费价格指数是一个反映居民家庭一般所购买的消费品和服务项目价格水平变动情况的宏观经济指标，它是衡量通货膨胀的主要指标之一。
某年商品的实际价格与名义价格之间的关系为：
某年商品的实际价格＝基准年消费物价指数/计算年消费物价指数×计算年的名义价格。
(NEW)平狄克《微观经济学》(第7版)课后习题详解
目 录第1篇 导论：市场和价格第1章 绪 论1.1 课后复习题详解1.2 课后练习题详解第2章 供给和需求的基本原理2.1 课后复习题详解2.2 课后练习题详解第2篇 生产者、消费者以及竞争性市场第3章 消费者行为3.1 课后复习题详解3.2 课后练习题详解第4章 个人需求和市场需求4.1 课后复习题详解4.2 课后练习题详解第4章附录 需求理论——一种数学的处理方法课后练习题详解第5章 不确定性与消费者行为5.1 课后复习题详解5.2 课后练习题详解第6章 生 产6.1 课后复习题详解6.2 课后练习题详解第7章 生产成本7.1 课后复习题详解7.2 课后练习题详解第7章附录 生产与成本理论——一种数学的处理方法课后练习题详解第8章 利润最大化和竞争性供给8.1 课后复习题详解8.2 课后练习题详解第9章 竞争性市场分析9.1 课后复习题详解9.2 课后练习题详解第3篇 市场结构和竞争策略第10章 市场势力：垄断与买方垄断10.1 课后复习题详解10.2 课后练习题详解第11章 有市场势力的定价11.1 课后复习题详解11.2 课后练习题详解第11章附录 联合厂商的内部转移定价课后练习题详解第12章 垄断竞争和寡头垄断12.1 课后复习题详解12.2 课后练习题详解第13章 博弈论和竞争策略13.1 课后复习题详解13.2 课后练习题详解第14章 投入要素市场14.1 课后复习题详解14.2 课后练习题详解第15章 投资、时间及资本市场15.1 课后复习题详解15.2 课后练习题详解第4篇 信息、市场失灵以及政府的角色第16章 一般均衡与经济效率16.1 课后复习题详解16.2 课后练习题详解第17章 信息不对称市场17.1 课后复习题详解17.2 课后练习题详解第18章 外部性与公共品18.1 课后复习题详解18.2 课后练习题详解附录：指定平狄克《微观经济学》教材为考研参考书目的院校列表第1篇 导论：市场和价格第1章 绪 论1.1 课后复习题详解1．人们常说，一个好的理论是可以用经验研究和实证研究来加以证伪的。
(中文版)平狄克《微观经济学》全部课后答案
(中文版)平狄克《微观经济学》全部课后答案第一章复习题1．市场是通过相互作用决定一种或一系列产品价格的买卖双方的集合，因此可以把市场看作决定价格的场所。
行业是出售相同的或紧密相关的产品的厂商的集合，一个市场可以包括许多行业。
2．评价一个理论有两个步骤：首先，需要检验这个理论假设的合理性；第二，把该理论的预测和事实相比较以此来验证它。
如果一个理论无法被检验的话，它将不会被接受。
因此，它对我们理解现实情况没有任何帮助。
3．实证分析解释“是什么”的问题，而规范分析解释的是“应该是什么”的问题。
对供给的限制将改变市场的均衡。
A中包括两种分析，批评这是一种“失败的政策”——是规范分析，批评其破坏了市场的竞争性——是实证分析。
B向我们说明在燃油的配给制下总社会福利的被损坏——是实证分析。
4．由于两个市场在空间上是分离的，商品在两地间的运输是套利实现的条件。
如果运输成本为零，则可以在Oklahoma购买汽油，到New Jersey出售，赚取差价；如果这个差价无法弥补运输成本则不存在套利机会。
5．商品和服务的数量与价格由供求关系决定。
鸡蛋的实际价格从1970年至1985年的下降，一方面是由于人们健康意识的提高而导致鸡蛋需求的减少，同时也因为生产成本的降低。
在这两种因素下，鸡蛋的价格下降了。
大学教育的实际价格的升高，是由于越来越多的人倾向于获得大学教育而导致需求提高，同时教育的成本也在升高。
在这两方面因素作用下，大学教育费用提高了。
6．日圆相对美圆来说，价值升高，升值前相比，兑换同样数量的日圆需要付出更多的美圆。
由汇率的变化引起购买力的变化，在日本市场出售的美国汽车，由于美圆贬值日圆升值，持有日圆的消费者将较以前支付较底的价格；而在美国市场出售的日本汽车，由于日圆升值美圆贬值，持有美圆的消费者将面对较以前提高的价格。
4.长期弹性和短期弹性区别在于消费者对价格变化的反映速度以及可获得的替代品。
对纸巾这样的非耐用品，价格上升，消费者在短期内的反映很小。
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第一章复习题1．市场是通过相互作用决定一种或一系列产品价格的买卖双方的集合，因此可以把市场看作决定价格的场所。
行业是出售相同的或紧密相关的产品的厂商的集合，一个市场可以包括许多行业。
2．评价一个理论有两个步骤：首先，需要检验这个理论假设的合理性；第二，把该理论的预测和事实相比较以此来验证它。
如果一个理论无法被检验的话，它将不会被接受。
因此，它对我们理解现实情况没有任何帮助。
3．实证分析解释“是什么”的问题，而规范分析解释的是“应该是什么”的问题。
对供给的限制将改变市场的均衡。
A中包括两种分析，批评这是一种“失败的政策”——是规范分析，批评其破坏了市场的竞争性——是实证分析。
B向我们说明在燃油的配给制下总社会福利的被损坏——是实证分析。
4．由于两个市场在空间上是分离的，商品在两地间的运输是套利实现的条件。
如果运输成本为零，则可以在Oklahoma购买汽油，到New Jersey出售，赚取差价；如果这个差价无法弥补运输成本则不存在套利机会。
5．商品和服务的数量与价格由供求关系决定。
鸡蛋的实际价格从1970年至1985年的下降，一方面是由于人们健康意识的提高而导致鸡蛋需求的减少，同时也因为生产成本的降低。
在这两种因素下，鸡蛋的价格下降了。
大学教育的实际价格的升高，是由于越来越多的人倾向于获得大学教育而导致需求提高，同时教育的成本也在升高。
在这两方面因素作用下，大学教育费用提高了。
6．日圆相对美圆来说，价值升高，升值前相比，兑换同样数量的日圆需要付出更多的美圆。
由汇率的变化引起购买力的变化，在日本市场出售的美国汽车，由于美圆贬值日圆升值，持有日圆的消费者将较以前支付较底的价格；而在美国市场出售的日本汽车，由于日圆升值美圆贬值，持有美圆的消费者将面对较以前提高的价格。
4.长期弹性和短期弹性区别在于消费者对价格变化的反映速度以及可获得的替代品。
对纸巾这样的非耐用品，价格上升，消费者在短期内的反映很小。
但在长期，对纸巾的需求将会变得富有弹性。
对于象电视机这样的耐用消费品，在短期内，价格的变动可能会引起需求的剧烈变化，价格的上升可能会使消费者推迟购买。
因此耐用品的需求在长期是富有弹性的。
5. 供给价格弹性是供给量变动的百分比和价格变动百分比的比值。
价格上升将引起供给的增加。
有些厂商在短期内，由于生产能力的限制无法迅速增加产量。
这样，在短期内，供给是缺乏弹性的。
然而在长期情况下，厂商可以调整生产规模，因而，从长期来看，供给是富有弹性的。
6. 如果商品价格被定在市场出清水平以下，厂商愿意提供的产量则低于消费者希望购买的数量。
短缺的程度则取决于供求的相对弹性。
供求均富有弹性情况下的缺口要大于双方缺乏弹性时的情况。
消费者无法在价格管制的情况下购买到他想购买到的数量。
他将去购买替代品，这样，替a.消费者将增加苹果需求，导致需求曲线外移动。
均衡价格和销售量都将增加。
b.由于橙子具有替代性，苹果的需求曲线将外移，均衡价格和销售量都将增加。
c.产量的下降将导致供给曲线向内移动，均衡价格上升，销售量下降。
d.苹果采摘着的增加将使苹果生产成本下降，供给增加，均衡价格下降，销售量上升。
e.供给曲线将外移，均衡价格下降，销售量上升。
练习题1.a.EQQPPPQQP DDDDD ==∆∆∆∆.P = 80，E d=–0.4 P = 100, E d=–0.56 b.EQQPPPQQP SSSSS ==∆∆∆∆.P = 80, E s=0.5.P = 100, E s=0.56c.均衡价格和数量为$100 ，18 million.d.价格定在80$，需求为20 million.，供给为16 million.，相差4 million.2.Q S = 1,800 + 240PQ D = 2,580 - 194P.Q= (2,580 - 194P) + 200 = 2,780 - 194PD1,800 + 240P = 2,780 - 194P, or434P = 980, or P* = $2.26 per bushel.Q S = 1,800 + (240)(2.26) = 2,342Q D = 2,780 - (194)(2.26) = 2,342.3.a.100 - 5P = 50 + 5P, P = $500.Q D = 100 - (5)(5) = 75Q S = 50 + (5)(5) = 75.租金在500美金时，750,000公寓可以被租掉。
当租金被控制在100美金时，供给量将达到550,000 (Q S= 50 + (5)(100) = 550)，比管制前减少了200,000。
假设每个公寓可容纳一个三口之家，将有600,000离开城市。
Figure 2.3b.当租金达到900美金时，公寓的供给为50 + 5(9) = 95，or 950,000这将超过均衡水平200,000。
因此(0.5)(200,000) = 100,000 个公寓被新建。
但是需求仅仅为550,000。
4.a.由总需求Q = 3,550 - 266P, 国内需求, Q d= 1,000 - 46P, ,得到出口需求Q e=2,550 - 220P.均衡价格：3,550 - 266P - 1,800 + 240P, orP = $3.46.需求减少40％，因此总需求Q D = Q d + 0.6Q e= 1,000 - 46P + (0.6)(2,550 - 220P) = 2,530 - 178P.均衡价格1,800 + 240P = 2,530 - 178P, orP = $1.75,在这一价格，市场出清量为2,219 million bushels，总收益从$9.1 billion 降至$3.9 billion.这将令大部分农民痛苦。
b.3美金的价格下市场并不在均衡状态，Demand = 1000 - 46(3) = 862. Supply = 1800 + 240(3) = 2,520, 超额供给 2,520 - 862 = 1,658.政府必须购买这个多余产量来支持价格，花费$3(1.66 million) = $5.0 billion 每年。
5. a.Q D = a - bP . E bP Q D =-F H G I KJ **. E D= -0.4 (长期价格弹性), P* = 0.75 (均衡价格), Q* = 7.5 (均衡产量).-=-F H I K 0407575...b, or b = 4.7.5 = a - (4)(0.75), or a = 10.5.Q D = 10.5 - 4P .b.)需求下降20％:'Q D=-=-0810548432....a f a fP P .8.4 - 3.2P = -4.5 + 16P , orP = 0.672.6. a.D = 24.08 - 0.06P S C = 11.74 + 0.07P .在没有OPEC 组织下的供给S c = Q * = 13.E S = 0.10 ， P * = $18, E S = d (P */Q *) ， d = 0.07. 代入 d , S c , ， P , c = 11.74 and S c = 11.74 + 0.07P .同样的, 因为 Q D = 23, E D = -b (P */Q *) = -0.05, b = 0.06. 代入 b , Q D = 23, ， P = 18 23 = a - 0.06(18), a = 24.08. 因此 Q D = 24.08 - 0.06P .b.D = 32.18 - 0.51P S C = 7.78 + 0.29P .如上, E S = 0.4 ， E D = -0.4: E S = d (P */Q *) ， E D = -b(P*/Q*), 0.4 = d (18/13) and-0.4 = -b(18/23).所以d = 0.29 ，b = 0.51.S c = c + dP，Q D = a - bP,13 = c + (0.29)(18) ，23 = a - (0.51)(18).So c = 7.78 ，a = 32.18.c.减产60亿桶后：S c' = 4 + S c = 11.74 + 4 + 0.07P = 15.74 + 0.07P，S" = 4 + S c = 11.78 + 0.29P.15.74 + 0.07P = 24.08 - 0.06P,短期中，P = $64.15;11.78 + 0.29P = 32.18 - 0.51P,长期中，P = $24.297.a.供给: Q = 14 + 2P G + 0.25P O需求: Q = -5P G + 3.75P O需求交叉弹性为：EQPPQGOGOGG=FH GIK JFH GIK J∆∆.设需求函数为：Q G = a - bP G + eP O(收入为常量), 则∆∆QPGOFH GIK J= e. 将它代入交叉弹性公式, E e P QPOOG=FH GIK J**, P O*andQ G*是均衡价格和产量. 我们知道P O*= $8 ，Q G*= 20 百万立方英尺(Tcf). 解得e,158 20.=FH GIK Je, e = 3.75.同样得, 供给方程可表示为:Q G = c + dP G + gP O,交叉价格弹性为gPQOG**FH GIK J, e= 0.1.⎪⎭⎫⎝⎛=2081.0g , g = 0.25.E S = 0.2, P* = 2, Q* = 20. 因此⎪⎭⎫⎝⎛=2022.0d , d = 2.同样, E D = -0.5, 所以⎪⎭⎫⎝⎛=-2025.0b , b = -5.将d, g, b , ， e 代入供给，需求方程，解得：20 = c + (2)(2) + (0.25)(8), c = 14, 20 = a - (5)(2) + (3.75)(8), a = 0.如果油价为$8.00，意味着天然气价格为$2.00。
将油价代入供求方程，得到天然气价格14 + 2P G + (0.25)(8) = -5P G + (3.75)(8), 7P G = 14, orP G = $2.00.b.需求: Q D = (-5)(1.50) + (3.75)(8) = 22.5, 供给: Q S = 14 + (2)(1.5) + (0.25)(8) = 19.在这种情况下将出现超额需求3.5 Tcf.c.需求: Q D = -5P G + (3.75)(16) = 60 - 5P G , 供给: Q S = 14 + 2P G + (0.25)(16) = 18 + 2P G .18 + 2P G = 60 - 5P G , ，P G = $6.第三章复习题1、偏好的可传递性是指：如果消费者在市场篮子A和B中更偏好A，在B和C中更偏好B，那么消费者A和C中更偏好A。