曼昆微观经济学答案ch17

曼昆微观经济学课后练习英文答案集团标准化办公室：[VV986T-J682P28-JP266L8-68PNN]the link between buyers’ willingness to pay for a good and the demandcurve.how to define and measure consumer surplus.the link between sellers’ costs of producing a good and the supply curve.how to define and measure producer surplus.that the equilibrium of supply and demand maximizes total surplus in amarket.CONTEXT AND PURPOSE:Chapter 7 is the first chapter in a three-chapter sequence on welfare economics and market efficiency. Chapter 7 employs the supply and demand model to develop consumer surplus and producer surplus as a measure of welfare and market efficiency. These concepts are then utilized in Chapters 8 and 9 to determine the winners and losers from taxation and restrictions on international trade.The purpose of Chapter 7 is to develop welfare economics—the study of how the allocation of resources affects economic well-being. Chapters 4 through 6 employed supply and demand in a positive framework, which focused on the question, “What is the equilibrium price and quantity in a market” This chapter now addresses the normative question, “Is the equilibrium price and quantity in a market the best possible solution to the resource allocation problem, or is it simply the price and quantity that balance supply and demand” Students will discover that under most circumstances the equilibrium price and quantity is also the one that maximizes welfare.KEY POINTS:Consumer surplus equals buyers’ willingness to pay for a good minus the amount they actually pay for it, and it measures the benefit buyers get from participating in a market. Consumer surplus can be computed by finding the area below the demand curve and above the price.Producer surplus equals the amount sellers receive for their goods minus their costs of production, and it measures the benefit sellers get from participating in a market. Producer surplus can be computed by finding the area below the price and above the supply curve.An allocation of resources that maximizes the sum of consumer and producer surplus is said to be efficient. Policymakers are often concerned with the efficiency, as well as the equality, of economic outcomes.The equilibrium of supply and demand maximizes the sum of consumer andproducer surplus. That is, the invisible hand of the marketplace leadsbuyers and sellers to allocate resources efficiently.Markets do not allocate resources efficiently in the presence of market failures such as market power or externalities.CHAPTER OUTLINE:I. Definition of welfare economics: the study of how the allocation of resources affects economic well-being.A. Willingness to Pay1. Definition of willingness to pay: the maximum amount that a buyer will pay for a good.2. Example: You are auctioning a mint-condition recording of Elvis Presley’s first album. Four buyers show up. Their willingness to pay is as follows:If the bidding goes to slightly higher than $80, all buyersdrop out except for John. Because John is willing to paymore than he has to for the album, he derives some benefitfrom participating in the market.3. Definition of consumer surplus: the amount a buyer is willing to payfor a good minus the amount the buyer actually pays for it.4. Note that if you had more than one copy of the album, the price in the auction would end up being lower (a little over $70 in the case of two albums) and both John and Paul would gain consumer surplus.B. Using the Demand Curve to Measure Consumer Surplus1. We can use the information on willingness to pay to derive a demandmarginal buyer . Because the demand curve shows the buyers’ willingness to pay, we can use the demand curve to measure c onsumer surplus.C. How a Lower Price Raises Consumer Surplussurplus because they are paying less for the product than before (area A on the graph).b. Because the price is now lower, some new buyers will enter the market and receive consumer surplus on these additional units of output purchased (area B on the graph).D. What Does Consumer Surplus Measure?1. Remember that consumer surplus is the difference between the amount that buyers are willing to pay for a good and the price that they actually pay.2. Thus, it measures the benefit that consumers receive from the good as the buyers themselves perceive it.III. Producer SurplusA. Cost and the Willingness to Sell1. Definition of cost: the value of everything a seller must give up to produce a good .2. Example: You want to hire someone to paint your house. You accept bidsfor the work from four sellers. Each painter is willing to work if the priceyou will pay exceeds her opportunity cost. (Note that this opportunity costthus represents willingness to sell.) The costs are:sellers will drop out except for Grandma. Because Grandma receives more than she would require to paint the house, she derives some benefit from producing in the market.4. Definition of producer surplus: the amount a seller is paid for a good minus the seller’s cost of providing it.5. Note that if you had more than one house to paint, the price in the auction would end up being higher (a little under $800 in the case of two houses) and both Grandma and Georgia would gain producer surplus.ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price ceilings from Chapter 6. Redraw themarket for two-bedroom apartments in your town. Draw in a priceceiling below the equilibrium price.Then go through:consumer surplus before the price ceiling is put into place. consumer surplus after the price ceiling is put into place. You will need to take some time to explain the relationship between the producers’ willingness to sell and the cost of producing the good. The relationship between cost and the supply curve is not as apparent as the relationship between the It is important to stress that consumer surplus is measured inmonetary terms. Consumer surplus gives us a way to place amonetary cost on inefficient market outcomes (due to governmentB. Using the Supply Curve to Measure Producer Surplus1. We can use the information on cost (willingness to sell) to derive a2.the cost of the marginal seller. Because the supply curve shows the sellers’ cost (willingness to sell), we can use the supply curve to measure producer surplus.C. How a Higher Price Raises Producer Surplussurplus because they are receiving more for the product than before (area C on the graph).b. Because the price is now higher, some new sellers will enter the market and receive producer surplus on these additional units of output sold (area D on the graph).D. Producer surplus is used to measure the economic well-being of producers,ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price floors from Chapter 6. Redraw the marketfor an agricultural product such as corn. Draw in a price supportabove the equilibrium price.Then go through:producer surplus before the price support is put in place.producer surplus after the price support is put in place.Make sure that you discuss the cost of the price support tomuch like consumer surplus is used to measure the economic well-being of consumers.IV. Market EfficiencyA. The Benevolent Social Planner1. The economic well-being of everyone in society can be measured by total surplus, which is the sum of consumer surplus and producer surplus:Total Surplus = Consumer Surplus + Producer SurplusTotal Surplus = (Value to Buyers – Amount Paid byBuyers) +(Amount Received by Sellers – Cost to Sellers)Because the Amount Paid by Buyers = Amount Received bySellers:2. Definition of efficiency: the property of a resource allocation of maximizing the total surplus received by all members of society .3. Definition of equality: the property of distributing economicprosperity uniformly the members of society .a. Buyers who value the product more than the equilibrium price will purchase the product; those who do not, will not purchase the product. Inother words, the free market allocates the supply of a good to the buyers who value it most highly, as measured by their willingness to pay.b. Sellers whose costs are lower than the equilibrium price will produce the product; those whose costs are higher, will not produce the product. Inother words, the free market allocates the demand for goods to the sellers who can produce it at the lowest cost.value of the product to the marginal buyer is greater than the cost to the marginal seller so total surplus would rise if output increases.Pretty Woman, Chapter 6. Vivien (Julia Roberts) and Edward(Richard Gere) negotiate a price. Afterward, Vivien reveals shewould have accepted a lower price, while Edward admits he wouldhave paid more. If you have done a good job of introducingconsumer and producer surplus, you will see the light bulbs gob. At any quantity of output greater than the equilibrium quantity, the value of the product to the marginal buyer is less than the cost to the marginal seller so total surplus would rise if output decreases.3. Note that this is one of the reasons that economists believe Principle #6: Markets are usually a good way to organize economic activity.C. In the News: Ticket Scalping1. Ticket scalping is an example of how markets work to achieve anefficient outcome.2. This article from The Boston Globe describes economist Chip Case’sexperience with ticket scalping.D. Case Study: Should There Be a Market in Organs?1. As a matter of public policy, people are not allowed to sell their organs.a. In essence, this means that there is a price ceiling on organs of $0.b. This has led to a shortage of organs.2. The creation of a market for organs would lead to a more efficientallocation of resources, but critics worry about the equity of a market system for organs.V. Market Efficiency and Market FailureA. To conclude that markets are efficient, we made several assumptions about how markets worked.1. Perfectly competitive markets.2. No externalities.B. When these assumptions do not hold, the market equilibrium may not be efficient.C. When markets fail, public policy can potentially remedy the situation. SOLUTIONS TO TEXT PROBLEMS:Quick Quizzes1. Figure 1 shows the demand curve for turkey. The price of turkey is P 1and the consumer surplus that results from that price is denoted CS. Consumer surplus is the amount a buyer is willing to pay for a good minus the amount the buyer actually pays for it. It measures the benefit to buyers ofparticipating in a market.Figure 1 Figure 22. Figure 2 shows the supply curve for turkey. The price of turkey is P 1and the producer surplus that results from that price is denoted PS. Producer surplus is the amount sellers are paid for a good minus the sellers’ cost of providing it (measured by the supply curve). It measures the benefit to sellers of participating in a market.It would be a good idea to remind students that there are circumstances when the market process does not lead to the most efficient outcome. Examples include situations such as when a firm (or buyer) has market power over price or when there areFigure 33. Figure 3 shows the supply and demand for turkey. The price of turkey is P, consumer surplus is CS, and producer surplus is PS. Producing more turkeys 1than the equilibrium quantity would lower total surplus because the value to the marginal buyer would be lower than the cost to the marginal seller on those additional units.Questions for Review1. The price a buyer is willing to pay, consumer surplus, and the demand curve are all closely related. The height of the demand curve represents the willingness to pay of the buyers. Consumer surplus is the area below the demand curve and above the price, which equals the price that each buyer is willing to pay minus the price actually paid.2. Sellers' costs, producer surplus, and the supply curve are all closely related. The height of the supply curve represents the costs of the sellers. Producer surplus is the area below the price and above the supply curve, which equals the price received minus each seller's costs of producing the good.Figure 43. Figure 4 shows producer and consumer surplus in a supply-and-demand diagram.4. An allocation of resources is efficient if it maximizes total surplus, the sum of consumer surplus and producer surplus. But efficiency may not be the only goal of economic policymakers; they may also be concerned about equitythe fairness of the distribution of well-being.5. The invisible hand of the marketplace guides the self-interest of buyers and sellers into promoting general economic well-being. Despite decentralized decision making and self-interested decision makers, free markets often lead to an efficient outcome.6. Two types of market failure are market power and externalities. Market power may cause market outcomes to be inefficient because firms may cause price and quantity to differ from the levels they would be under perfect competition, which keeps total surplus from being maximized. Externalities are side effects that are not taken into account by buyers and sellers. As a result, the free market does not maximize total surplus.Problems and Applications1. a. Consumer surplus is equal to willingness to pay minus the price paid. Therefore, Melissa’s willingness to pay must be $200 ($120 + $80).b. Her consumer surplus at a price of $90 would be $200 $90 = $110.c. If the price of an iPod was $250, Melissa would not have purchased one because the price is greater than her willingness to pay. Therefore, she would receive no consumer surplus.2. If an early freeze in California sours the lemon crop, the supply curve for lemons shifts to the left, as shown in Figure 5. The result is a rise in the price of lemons and a decline in consumer surplus from A + B + C to just A. So consumer surplus declines by the amount B + C.Figure 5 Figure 6In the market for lemonade, the higher cost of lemons reduces the supply of lemonade, as shown in Figure 6. The result is a rise in the price of lemonade and a decline in consumer surplus from D + E + F to just D, a loss of E + F. Note that an event that affects consumer surplus in one market oftenhas effects on consumer surplus in other markets.3. A rise in the demand for French bread leads to an increase in producer surplus in the market for French bread, as shown in Figure 7. The shift of the demand curve leads to an increased price, which increases producer surplusfrom area A to area A + B + C.Figure 7The increased quantity of French bread being sold increases the demandfor flour, as shown in Figure 8. As a result, the price of flour rises, increasing producer surplus from area D to D + E + F. Note that an event that affects producer surplus in one market leads to effects on producer surplus in related markets.Figure 84. a.Figure 9b. When the price of a bottle of water is $4, Bert buys two bottles of water. His consumer surplus is shown as area A in the figure. He values hisfirst bottle of water at $7, but pays only $4 for it, so has consumer surplus of $3. He values his second bottle of water at $5, but pays only $4 for it, so has consumer surplus of $1. Thus Bert’s total consumer surplus is $3 + $1 = $4, which is the area of A in the figure.c. When the price of a bottle of water falls from $4 to $2, Bert buys three bottles of water, an increase of one. His consumer surplus consists of both areas A and B in the figure, an increase in the amount of area B. He gets consumer surplus of $5 from the first bottle ($7 value minus $2 price), $3from the second bottle ($5 value minus $2 price), and $1 from the third bottle ($3 value minus $2 price), for a total consumer surplus of $9. Thus consumer surplus rises by $5 (which is the size of area B) when the price of a bottle of water falls from $4 to $2.5. a.Figure 10b. When the price of a bottle of water is $4, Ernie sells two bottles of water. His producer surplus is shown as area A in the figure. He receives $4 for his first bottle of water, but it costs only $1 to produce, so Ernie has producer surplus of $3. He also receives $4 for his second bottle of water, which costs $3 to produce, so he has producer surplus of $1. Thus Ernie’s total producer surplus is $3 + $1 = $4, which is the area of A in the figure.c. When the price of a bottle of water rises from $4 to $6, Ernie sells three bottles of water, an increase of one. His producer surplus consists of both areas A and B in the figure, an increase by the amount of area B. He gets producer surplus of $5 from the first bottle ($6 price minus $1 cost), $3 from the second bottle ($6 price minus $3 cost), and $1 from the third bottle ($6 price minus $5 price), for a total producer surplus of $9. Thus producer surplus rises by $5 (which is the size of area B) when the price of a bottle of water rises from $4 to $6.6. a. From Ernie’s supply schedule and Bert’s demand schedule, thean equilibrium quantity of two.b. At a price of $4, consumer surplus is $4 and producer surplus is $4, as shown in Problems 3 and 4 above. Total surplus is $4 + $4 = $8.c. If Ernie produced one less bottle, his producer surplus would decline to $3, as shown in Problem 4 above. If Bert consumed one less bottle, hisconsumer surplus would decline to $3, as shown in Problem 3 above. So total surplus would decline to $3 + $3 = $6.d. If Ernie produced one additional bottle of water, his cost would be $5, but the price is only $4, so his producer surplus would decline by $1. If Bert consumed one additional bottle of water, his value would be $3, but the price is $4, so his consumer surplus would decline by $1. So total surplus declines by $1 + $1 = $2.7. a. The effect of falling production costs in the market for stereos results in a shift to the right in the supply curve, as shown in Figure 11. As a result, the equilibrium price of stereos declines and the equilibriumquantity increases.Figure 11b. The decline in the price of stereos increases consumer surplus from area A to A + B + C + D, an increase in the amount B + C + D. Prior to the shift in supply, producer surplus was areas B + E (the area above the supply curve and below the price). After the shift in supply, producer surplus is areas E + F + G. So producer surplus changes by the amount F + G – B, which may be positive or negative. The increase in quantity increases producer surplus, while the decline in the price reduces producer surplus. Because consumer surplus rises by B + C + D and producer surplus rises by F + G – B, total surplus rises by C + D + F + G.c. If the supply of stereos is very elastic, then the shift of the supply curve benefits consumers most. To take the most dramatic case, suppose the supply curve were horizontal, as shown in Figure 12. Then there is no producer surplus at all. Consumers capture all the benefits of falling production costs, with consumer surplus rising from area A to area A + B.Figure 128. Figure 13 shows supply and demand curves for haircuts. Supply equals demand at a quantity of three haircuts and a price between $4 and $5. Firms A, C, and D should cut the hair of Ellen, Jerry, and Phil. Oprah’s willingnessto pay is too low and firm B’s costs are too high, so they do not participate. The maximum total surplus is the area between the demand and supply curves, which totals $11 ($8 value minus $2 cost for the first haircut, plus $7 value minus $3 cost for the second, plus $5 value minus $4 cost for the third).Figure 139. a. The effect of falling production costs in the market for computers results in a shift to the right in the supply curve, as shown in Figure 14. As a result, the equilibrium price of computers declines and the equilibrium quantity increases. The decline in the price of computers increases consumer surplus from area A to A + B + C + D, an increase in the amount B + C + D.Figure 14 Figure 15Prior to the shift in supply, producer surplus was areas B + E(the area above the supply curve and below the price). After theshift in supply, producer surplus is areas E + F + G. So producersurplus changes by the amount F + G – B, which may be positive ornegative. The increase in quantity increases producer surplus,while the decline in the price reduces producer surplus. Becauseconsumer surplus rises by B + C + D and producer surplus rises byF +G – B, total surplus rises by C + D + F + G.b. Because typewriters are substitutes for computers, the decline in the price of computers means that people substitute computers for typewriters, shifting the demand for typewriters to the left, as shown in Figure 15. The result is a decline in both the equilibrium price and equilibrium quantity of typewriters. Consumer surplus in the typewriter market changes from area A + B to A + C, a net change of C – B. Producer surplus changes from area C + D + E to area E, a net loss of C + D. Typewriter producers are sad about technological advances in computers because their producer surplus declines.c. Because software and computers are complements, the decline in the price and increase in the quantity of computers means that the demand for software increases, shifting the demand for software to the right, as shown in Figure 16. The result is an increase in both the price and quantity of software. Consumer surplus in the software market changes from B + C to A + B, a net change of A – C. Producer surplus changes from E to C + D + E, an increase of C + D, so software producers should be happy about the technological progress in computers.Figure 16d. Yes, this analysis helps explain why Bill Gates is one the world’s richest people, because his company produces a lot of software that is a complement with computers and there has been tremendous technological advance in computers.10. a. With Provider A, the cost of an extra minute is $0. WithProvider B, the cost of an extra minute is $1.b. With Provider A, my friend will purchase 150 minutes [= 150 –(50)(0)]. With Provider B, my friend would purchase 100 minutes [=150 – (50)(1)].c. With Provider A, he would pay $120. The cost would be $100 with Provider B.Figure 17d. Figure 17 shows the friend’s demand. With Provider A, he buys 150minutes and his consumer surplus is equal to (1/2)(3)(150) – 120= 105. With Provider B, his consumer surplus is equal to(1/2)(2)(100) = 100.e. I would recommend Provider A because he receives greater consumer surplus.11. a. Figure 18 illustrates the demand for medical care. If each procedure has a price of $100, quantity demanded will be Q1 procedures.Figure 18b. If consumers pay only $20 per procedure, the quantity demanded will be Qprocedures. Because the cost to society is $100, the number of procedures 2performed is too large to maximize total surplus. The quantity that maximizes total surplus is Q1 procedures, which is less than Q2.c. The use of medical care is excessive in the sense that consumers get procedures whose value is less than the cost of producing them. As a result, the economy’s total surplus is reduced.d. To prevent this excessive use, the consumer must bear the marginal cost of the procedure. But this would require eliminating insurance. Another possibility would be that the insurance company, which pays most of the marginal cost of the procedure ($80, in this case) could decide whether the procedure should be performed. But the insurance company does not get the benefits of the procedure, so its decisions may not reflect the value to the consumer.。

第一篇导言第一章经济学十大原理复习题1．列举三个你在生活中面临的重要权衡取舍的例子。

答：①大学毕业后，面临着是否继续深造的选择，选择继续上学攻读研究生学位，就意味着在今后三年中放弃参加工作、赚工资和积累社会经验的机会；②在学习内容上也面临着很重要的权衡取舍，如果学习《经济学》，就要减少学习英语或其他专业课的时间；③对于不多的生活费的分配同样面临权衡取舍，要多买书，就要减少在吃饭、买衣服等其他方面的开支。

2．看一场电影的机会成本是什么?答：看一场电影的机会成本是在看电影的时间里做其他事情所能获得的最大收益，例如：看书、打零工。

3．水是生活必需的。

一杯水的边际利益是大还是小呢?答：这要看这杯水是在什么样的情况下喝，如果这是一个人五分钟内喝下的第五杯水，那么他的边际利益很小，有可能为负；如果这是一个极度干渴的人喝下的第一杯水，那么他的边际利益将会极大。

4．为什么决策者应该考虑激励?答：因为人们会对激励做出反应。

如果政策改变了激励，它将使人们改变自己的行为，当决策者未能考虑到行为如何由于政策的原因而变化时，他们的政策往往会产生意想不到的效果。

5．为什么各国之间的贸易不像竞赛一样有赢家和输家呢?答：因为贸易使各国可以专门从事自己最擅长的活动，并从中享有更多的各种各样的物品与劳务。

通过贸易使每个国家可供消费的物质财富增加，经济状况变得更好。

因此，各个贸易国之间既是竞争对手，又是经济合作伙伴。

在公平的贸易中是“双赢”或者“多赢”的结果。

6．市场中的那只“看不见的手”在做什么呢?答：市场中那只“看不见的手”就是商品价格，价格反映商品自身的价值和社会成本，市场中的企业和家庭在作出买卖决策时都要关注价格。

因此，他们也会不自觉地考虑自己行为的(社会)收益和成本。

从而，这只“看不见的手”指引着千百万个体决策者在大多数情况下使社会福利趋向最大化。

7．解释市场失灵的两个主要原因，并各举出一个例子。

答：市场失灵的主要原因是外部性和市场势力。

曼昆微观经济学课后答案————————————————————————————————作者：————————————————————————————————日期：21.Consider the market for DVD movies,TV screens,and ticket at movie theaters. A．对每一对物品，确定它们是互补品还是替代品·DVD 和电视·DVD 和电影票·电视和电影票As: complements substitutes substitutesB．假设技术进步降低了制造电视机的成本。

画一个图说明电视机市场会发生什么变动。

As: demand curve不变supply curve向右移。

技术进步降低了制造电视机的成本，使电视机的供给曲线向右移动。

电视机的需求曲线不变。

电视机的均衡价格下降，均衡价格上升。

C．再画两个图说明电视机市场的变动如何影响DVD 市场和电影票市场。

答：DVD：demand curve不变supply curve向右移。

由于电视机和DVD 是互补品，电视机价格的下降使DVD 的需求增加。

需求增加引起DVD 均衡价格上升，均衡数量增加。

Movie tickets：supply curve不变demand curve向左移。

由于电视机和电影票是替代品，电视机价格的下降使电影票需求减少。

需求的减少使电影票的均衡价格下降，均衡数量减少。

2.Over the past 20 years,technological advance reduces the cost of computer chips.How do you think this affected the market for computers?For computer software?For typewriters?As: computer : supply curve向右移price 下降computer software: supply curve向右移price 下降typewriters : demand curve向左移3.Consider total cost and total revenue given in the following table:A．计算每种产量时的利润。

曼昆《经济学原理（微观经济学分册）》课后习题详解（第1篇）第1篇导言第1章经济学十大原理一、看法题1．稀缺性（scarcity）答：经济学研究的问题和经济物件都是以稀缺性为前提的。

稀缺性指在给定的时间内，相对于人的需求而言，经济资源的供应老是不足的，也就是资源的实用性与有限性。

人类花费各样物件的欲念是无穷的，知足这类欲念的物件，有的能够不付出任何代价而任意获得，称之为自由物件，如阳光和空气；但绝大部分物件是不可以自由取用的，因为世界上的资源（包含物质资源和人力资源）是有限的，这类有限的、为获取它一定付出某种代价的物件，称为“经济物件”。

正因为稀缺性的客观存在，地球上就存在着资源的有限性和人类的欲念与需求的无穷性之间的矛盾。

经济学的一个重要研究任务就是：“研究人们怎样进行决断，以便使用稀缺的或有限的生产性资源（土地、劳动、资本品如机器、技术知识）来生产各样商品，并把它们分派给不一样的社会成员进行花费。

”也就是从经济学角度来研究使用有限的资源来生产什么、怎样生产和为谁生产的问题。

2．经济学（economics）答：经济学是研究怎样将稀缺的资源有效地配置给互相竞争的用途，以令人类的欲望获取最大限度知足的科学。

时下常常有诸国内报刊文件的“现代西方经济学”一词，大多也都在这个意义上使用。

自从凯恩斯的名著《就业、利息和钱币通论》于1936年发布以后，西方经济学界对经济学的研究便分为两个部分：微观经济学与宏观经济学。

微观经济学是以单个经济主体（作为花费者的单个家庭或个人，作为生产者的单个厂商或公司，以及单个产品或生产因素市场）为研究对象，研究单个经济主风光对既定的资源拘束时怎样进行选择的科学。

宏观经济学则以整个公民经济为研究对象，主要着眼于对经济总量的研究。

3．效率（efficiency）答：效率指人们在实践活动中的产出与投入之比值，或许是效益与成本之比值，假如比值大，效率就高；反之，比值小，效率就低。

效率与产出或许利润的大小成正比，而与成本或投入成反比，也就是说，假如想提升效率，一定降低成本或投入，提升利润或产出。

第17章寡头17.1 复习笔记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．不完全竞争（1）概述竞争和垄断是市场结构的极端形式。

当市场上有许多提供基本相同产品的企业时就出现了竞争；当市场上只有一家企业时就出现了垄断。

但许多行业介于这两种极端之间，这些行业中的企业有竞争对手，同时又没有面临着使它们成为价格接受者的激烈竞争。

经济学家把这种状况称为不完全竞争。

（2）不完全竞争市场的两种类型寡头是只有少数几个卖者的市场，每个卖者都提供与其他企业相似或相同的产品。

因此，市场上任何一个卖者的行动都对其他卖者的利润有重大的影响。

垄断竞争描述一个有许多出售相似但不相同产品的企业的市场结构。

在垄断竞争的市场上，每家企业都垄断着自己生产的产品，但许多其他企业也生产争夺同样顾客的相似但不相同的产品。

2．寡头（1）卡特尔卡特尔指企业之间就有关生产与价格达成协议并以一致方式行事的企业集团。

寡头市场一旦形成了卡特尔，市场实际就是由一个垄断者提供服务，而且卡特尔不仅必须就总产量水平达成一致，而且还要就每个成员的生产量达成一致。

（2）寡头的均衡合作并达到垄断的结果会使寡头的状况更好，但由于他们追求自己的私利，最后不能达到垄断结果，因而并不能使他们共同的利润最大化。

每一个寡头都有增加生产并占有更大市场份额的诱惑，当他们每一个都努力这样做时，总产量增加了，而价格下降了。

当寡头企业个别地选择利润最大化的产量时，它们生产的产量大于垄断但小于竞争时的产量水平。

寡头价格低于垄断价格，但高于竞争价格（竞争价格等于边际成本）。

（3）寡头数量如何影响市场结果①寡头市场中增加产量的两种效应：a．产量效应：由于价格高于边际成本，在现行价格时每多销售1单位产品将增加利润。

第一章经济学十大原理问题与应用2．你正想决定是否去度假。

度假的大部分成本(机票、旅馆、放弃的工资)都用美元来衡量，但度假的收益是心理的。

你将如何比较收益与成本呢??答：这种心理上的收益可以用是否达到既定目标来衡量。

对于这个行动前就会作出的既定目标，我们一定有一个为实现目标而愿意承担的成本范围。

在这个可以承受的成本范围内，度假如果满足了既定目标，如：放松身心、恢复体力等等，那么，就可以说这次度假的收益至少不小于它的成本。

3．你正计划用星期六去从事业余工作，但一个朋友请你去滑雪。

去滑雪的真实成本是什么？现在假设你已计划这天在图书馆学习，这种情况下去滑雪的成本是什么？请解释之。

答：去滑雪的真实成本是周六打工所能赚到的工资，我本可以利用这段时间去工作。

如果我本计划这天在图书馆学习，那么去滑雪的成本是在这段时间里我可以获得的知识。

4．你在篮球比赛的赌注中赢了100美元。

你可以选择现在花掉它或在利率为5%的银行中存一年。

现在花掉100美元的机会成本是什么呢?答：现在花掉100 美元的机会成本是在一年后得到105 美元的银行支付(利息+本金)。

6．你的室友做饭比你好，但你打扫房间比你的室友快。

如果你的室友承担全部做饭工作，你承担全部打扫工作，那么你所要花费的时间比你们平均分摊两种家务时花费的时间多了还是少了？试举一个类似的例子，说明专业化和贸易如何使两个国家的状况变得更好。

答：我们俩各自承担自己擅长的工作比我们平均分摊两种家务时，我要花费的时间少了，因为娴熟的技巧使工作效率提高。

举例：假设A 国比B 国擅长生产丝绸，而B 国生产皮毛制品的效率比A 国高，如果A 国专门生产丝绸，B国专门生产皮毛制品，由于它们各自在相关生产上的优势，会使两种商品的生产率提高，有更多的丝绸和皮毛制品在市场上供应。

这样，A、B 两国间的专业分工和相互贸易使两国消费者有更多的丝绸和皮毛制品可供消费，两国的生活水平都提高了。

7．解释下列每一项政府活动的动机是关注平等还是关注效率。

曼昆《经济学原理（微观经济学分册）》（第6版）第17章寡头课后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。

一、概念题1．寡头（oligopoly）（山东大学2003研；西北大学2004研）答：寡头亦称“寡头垄断”或“寡占”，指只有几个提供相似或相同产品的卖者的市场结构。

在寡头市场上，整个行业（或市场）的产品（或劳务）的一大部分是由少数几个企业（或卖者）供给的。

作为卖主的垄断寡头之间仍然存在着竞争，每个寡头都要考虑竞争对手对于自己的每一行动的反应。

一方面，如果有一卖主为争取更大的市场销售份额而降低商品价格，那么其他卖主势必也会降低价格，最终使各个卖主的原有市场份额保持不变，而使利润减少。

另一方面，如果有一卖主提高价格，那么其他卖主就不一定会提高价格，从而使提高价格的卖主丧失原来占有的市场份额。

由于垄断寡头能预计到这种结果，垄断寡头不会轻易提价。

因此，在卖方寡头市场上，商品价格一般比较稳定。

2．博弈论（game theory）答：博弈论也称为对策论，指研究人们在各种决策下如何行事的一般分析理论。

博弈论被应用于政治、外交、军事、经济等研究领域。

博弈就是决策者在某种竞争场合下做出的决策，或者说，参加竞争的各方为了自己的利益而采取的对付对方的策略。

博弈模型是人们对博弈现象的抽象。

博弈论就是分析博弈模型的方法和理论，它研究的典型问题是两个或两个以上的参加者（称为局中人）在某种对抗性或竞争性的场合下各自做出决策，使自己这一方得到尽可能最有利的结果。

博弈模型一般至少含有以下三个要素：①局中人。

曼昆微观经济学课后答案作者: 日期:1 .C on sider the market for DVD movies,TV scree ns,a nd ticket at movie theaters.A •对每一对物品，确定它们是互补品还是替代品・DVD和电视・DVD和电影票・电视和电影票As: compleme nts substitutes substitutesB •假设技术进步降低了制造电视机的成本。

画一个图说明电视机市场会发生什么变动。

As: dema nd curve不娈supply curve向右移:技术进步降低了制造电视机的成本，使电视机的供给曲线向右移动。

电视机的需求曲线不变。

电视机的均衡价格下降，均衡价格上升。

C .再画两个图说明电视机市场的变动如何影响DVD市场和电影票市场。

答：DVD : dema nd curve不变supply curve向右移。

由于电视机和DVD是互补品，电视机价格的下降使DVD的需求增加。

需求增加引起DVD均衡价格上升，均衡数量增加。

Movie tickets : supply curve不变dema nd curve向左移。

由于电视机和电影票是替代品，电视机价格的下降使电影票需求减少。

需求的减少使电影票的均衡价格下降，均衡数量减少。

2.Over the past 20 years,tech no logical adva nee reduces the cost of computer chips.How do you think this affected the market for computers?For computer software?For typewriters?As: computer: supply curve 向右彳多price 卜降3.Consider total cost and total revenue given in the following table:产量01234567总成本89101113192737总收益08162432404856computer software: supply curve 向右彳多price 卜•降软件厂、・i) o _—八j IX2I uWhen MR=MC profit maximum 即Q=6 TC=27B・计算每种产量时的边际收益和边际成本。

✍ how to define and measure consumer surplus.✍ the link between sellers’ costs of producing a good and the supply curve.✍ how to define and measure producer surplus.✍ that the equilibrium of supply and demand maximizes total surplus in a market. CONTEXT AND PURPOSE:Chapter 7 is the first chapter in a three-chapter sequence on welfare economics and market efficiency. Chapter 7 employs the supply and demand model to develop consumer surplus and producer surplus as a measure of welfare and market efficiency. These concepts are then utilized in Chapters 8 and 9 to determine the winners and losers from taxation and restrictions on international trade.The purpose of Chapter 7 is to develop welfare economics—the study of how the allocation of resources affects economic well-being. Chapters 4 through 6 employed supply and demand in a positive framework, which focused on the question, “What is the equilibrium price and quantity in a market?” This chapter now addresses the normative question, “Is the equilibrium price and quantity in a market the best possible solution to the resource allocation problem, or is it simply the price and quantity that balance supply and demand?” Students will discover that under most circumstances the equilibrium price and quantity is also the one that maximizes welfare.KEY POINTS:? Consumer surplus equals buyers’ willingness to pay for a good minus the amount they actually pay for it, and it measures the benefit buyers get from participating in a market.Consumer surplus can be computed by finding the area below the demand curve and above the price.? Producer surplus equals the amount sellers receive for their goods minus their costs of production, and it measures the benefit sellers get from participating in a market. Producer surplus can be computed by finding the area below the price and above the supply curve.? An allocation of resources that maximizes the sum of consumer and producer surplus is said to be efficient. Policymakers are often concerned with the efficiency, as well as the equality, of economic outcomes.? The equilibrium of supply and demand maximizes the sum of consumer and producer surplus.That is, the invisible hand of the marketplace leads buyers and sellers to allocate resources efficiently.? Markets do not allocate resources efficiently in the presence of market failures such as market power or externalities.CHAPTER OUTLINE:I. Definition of welfare economics: the study of how the allocation of resources affects economic well-being.A. Willingness to Pay1. Definition of willingness to pay: the maximum amount that a buyer will pay for a good.2. Example: You are auctioning a mint-condition recording of Elvis Presley’s first album. Four buyers show up. Their willingness to pay is as follows:for John. Because John is willing to pay more than he has to for the album,he derives some benefit from participating in the market.3. Definition of consumer surplus: the amount a buyer is willing to pay for a good minus the amount the buyer actually pays for it.4. Note that if you had more than one copy of the album, the price in the auction would end up being lower (a little over $70 in the case of two albums) and both John and Paul would gain consumer surplus.B. Using the Demand Curve to Measure Consumer Surplus1. We can use the information on willingness to pay to derive a demand curve for the rare2. . Because the demand curve shows the buyers’ willingness to pay, we can use the demand curve to measure consumer surplus.C. How a Lower Price Raises Consumer Surplusare paying less for the product than before (area A on the graph).b. Because the price is now lower, some new buyers will enter the market and receive consumer surplus on these additional units of output purchased (area B on the graph).D. What Does Consumer Surplus Measure?1. Remember that consumer surplus is the difference between the amount that buyers are willing to pay for a good and the price that they actually pay.2. Thus, it measures the benefit that consumers receive from the good as the buyers themselves perceive it.III. Producer SurplusA. Cost and the Willingness to Sell1. Definition of cost: the value of everything a seller must give up to produce a good .2. Example: You want to hire someone to paint your house. You accept bids for the work from four sellers. Each painter is willing to work if the price you will pay exceeds her opportunity cost. (Note that this opportunity cost thus represents willingness to sell.) The costs are: ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price ceilings from Chapter 6. Redraw the market for two-bedroom apartments in your town. Draw in a price ceiling below the equilibriumprice.Then go through:✍ consumer surplus before the price ceiling is put into place.✍ consumer surplus after the price ceiling is put into place.You will need to take some time to explain the relationship between the producers’ willingness to sell and the cost of producing the good. The relationship between cost and the supply curve is not as apparent as the relationship between the demand curve and willingness to pay. It is important to stress that consumer surplus is measured in monetary terms. Consumer surplus gives us a way to place a monetary cost on inefficient market outcomes (due to government involvement or market failure).except for Grandma. Because Grandma receives more than she would require to paint the house, she derives some benefit from producing in the market.4.Definition of producer surplus: the amount a seller is paid for a good minus the seller’s cost of providing it.5. Note that if you had more than one house to paint, the price in the auction would end up being higher (a little under $800 in the case of two houses) and both Grandma and Georgia would gain producer surplus.B. Using the Supply Curve to Measure Producer Surplus1. We can use the information on cost (willingness to sell) to derive a supply curve for2. marginal seller . Because the supply curve shows the sellers’ cost (willingness to sell), we can use the supply curve to measure producer surplus.are receiving more for the product than before (area C on the graph).b. Because the price is now higher, some new sellers will enter the market and receive producer surplus on these additional units of output sold (area D on the graph).D. Producer surplus is used to measure the economic well-being of producers, much like consumer surplus is used to measure the economic well-being of consumers.ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price floors from Chapter 6. Redraw the market for anagricultural product such as corn. Draw in a price support above the equilibriumprice.Then go through:✍ producer surplus before the price support is put in place.✍ producer surplus after the price support is put in place.Make sure that you discuss the cost of the price support to taxpayers.IV.Market EfficiencyA. The Benevolent Social Planner1. The economic well-being of everyone in society can be measured by total surplus, which is the sum of consumer surplus and producer surplus:Total Surplus = Consumer Surplus + Producer SurplusTotal Surplus = (Value to Buyers – Amount Paid by Buyers) +(Amount Received by Sellers – Cost to Sellers)Because the Amount Paid by Buyers = Amount Received bySellers:2. Definition of efficiency: the property of a resource allocation of maximizing the total surplus received by all members of society .3. Definition of equality: the property of distributing economic prosperity uniformly the members of society .a. Buyers who value the product more than the equilibrium price will purchase the product; those who do not, will not purchase the product. In other words, the free market allocates the supply of a good to the buyers who value it most highly, as measured by their willingness to pay.b. Sellers whose costs are lower than the equilibrium price will produce the product; those whose costs are higher, will not produce the product. In other words, the free market allocates the demand for goods to the sellers who can produce it at the lowest cost.to the marginal buyer is greater than the cost to the marginal seller so total surplus would rise if output increases.b. At any quantity of output greater than the equilibrium quantity, the value of the product to the marginal buyer is less than the cost to the marginal seller so total surplus would rise if output decreases.3. Note that this is one of the reasons that economists believe Principle #6: Markets are usually a good way to organize economic activity.It would be a good idea to remind students that there are circumstances whenthe market process does not lead to the most efficient outcome. Examplesinclude situations such as when a firm (or buyer) has market power over priceor when there are externalities present. These situations will be discussed inlater chapters.Pretty Woman, Chapter 6. Vivien (Julia Roberts) and Edward (Richard Gere)negotiate a price. Afterward, Vivien reveals she would have accepted a lowerprice, while Edward admits he would have paid more. If you have done a goodjob of introducing consumer and producer surplus, you will see the light bulbsgo off above your students’ heads as they watch this clip.C. In the News: Ticket Scalping1. Ticket scalping is an example of how markets work to achieve an efficient outcome.2. This article from The Boston Globe de scribes economist Chip Case’s experience with ticket scalping.D. Case Study: Should There Be a Market in Organs?1. As a matter of public policy, people are not allowed to sell their organs.a. In essence, this means that there is a price ceiling on organs of $0.b. This has led to a shortage of organs.2. The creation of a market for organs would lead to a more efficient allocation of resources, but critics worry about the equity of a market system for organs.V. Market Efficiency and Market FailureA. To conclude that markets are efficient, we made several assumptions about how markets worked.1. Perfectly competitive markets.2. No externalities.B. When these assumptions do not hold, the market equilibrium may not be efficient.C. When markets fail, public policy can potentially remedy the situation. SOLUTIONS TO TEXT PROBLEMS:Quick Quizzes1. Figure 1 shows the demand curve for turkey. The price of turkey is P1 and the consumer surplus that results from that price is denoted CS. Consumer surplus is the amount a buyer is willing to pay for a good minus the amount the buyer actually pays for it. It measures the benefit to buyers of participating in a market.Figure 1 Figure 22. Figure 2 shows the supply curve for turkey. The price of turkey is P1 and the producer surplus that results from that price is denoted PS. Producer surplus is the amount sellers are paid for a good minus the sellers’ cost of providing it (measured by the supply curve). It measures the benefit to sellers of participating in a market.Figure 33. Figure 3 shows the supply and demand for turkey. The price of turkey is P1, consumer surplus is CS, and producer surplus is PS. Producing more turkeys than the equilibrium quantity would lower total surplus because the value to the marginal buyer would be lower than the cost to the marginal seller on those additional units.Questions for Review1. The price a buyer is willing to pay, consumer surplus, and the demand curve are all closely related. The height of the demand curve represents the willingness to pay of the buyers. Consumer surplus is the area below the demand curve and above the price, which equals the price that each buyer is willing to pay minus the price actually paid.2. Sellers' costs, producer surplus, and the supply curve are all closely related. The height of the supply curve represents the costs of the sellers. Producer surplus is the area below the price and above the supply curve, which equals the price received minus each seller's costs of producing the good.Figure 43. Figure 4 shows producer and consumer surplus in a supply-and-demand diagram.4. An allocation of resources is efficient if it maximizes total surplus, the sum of consumer surplus and producer surplus. But efficiency may not be the only goal of economic policymakers; they may also be concerned about equity the fairness of the distribution of well-being.5. The invisible hand of the marketplace guides the self-interest of buyers and sellers into promoting general economic well-being. Despite decentralized decision making and self-interested decision makers, free markets often lead to an efficient outcome.6. Two types of market failure are market power and externalities. Market power may cause market outcomes to be inefficient because firms may cause price and quantity to differ from the levels they would be under perfect competition, which keeps total surplus from being maximized. Externalities are side effects that are not taken into account by buyers and sellers. As a result, the free market does not maximize total surplus.Problems and Applications1. a. Consumer surplus is equal to willingness to pay minus the price paid. Therefore, Melissa’s willingness to pay must be $200 ($120 + $80).b. Her consumer surplus at a price of $90 would be $200 ? $90 = $110.c. If the price of an iPod was $250, Melissa would not have purchased one because the price is greater than her willingness to pay. Therefore, she would receive no consumer surplus.2. If an early freeze in California sours the lemon crop, the supply curve for lemons shifts to the left, as shown in Figure 5. The result is a rise in the price of lemons and a decline in consumer surplus from A + B + C to just A. So consumer surplus declines by the amount B + C.Figure 5 Figure 6In the market for lemonade, the higher cost of lemons reduces the supply of lemonade, as shown in Figure 6. The result is a rise in the price of lemonade and a decline in consumer surplus from D + E + F to just D, a loss of E + F. Note that an event that affects consumer surplus in one market often has effects on consumer surplus in other markets.3. A rise in the demand for French bread leads to an increase in producer surplus in the market for French bread, as shown in Figure 7. The shift of the demand curve leads to an increased price, which increases producer surplus from area A to area A + B + C.Figure 7The increased quantity of French bread being sold increases the demand for flour, as shown in Figure 8. As a result, the price of flour rises, increasing producer surplus from area Dto D + E + F. Note that an event that affects producer surplus in one market leads to effects on producer surplus in related markets.Figure 84. a.Figure 9b. When the price of a bottle of water is $4, Bert buys two bottles of water. His consumer surplus is shown as area A in the figure. He values his first bottle of water at $7, but pays only $4 for it, so has consumer surplus of $3. He values his second bottle of water at $5, but pays only $4for it, so has consumer surplus of $1. Thus Bert’s total consumer surplus is $3 + $1 = $4, which is the area of A in the figure.c. When the price of a bottle of water falls from $4 to $2, Bert buys three bottles of water, an increase of one. His consumer surplus consists of both areas A and B in the figure, an increase in the amount of area B. He gets consumer surplus of $5 from the first bottle ($7 value minus $2 price), $3 from the second bottle ($5 value minus $2 price), and $1 from the third bottle ($3 value minus $2 price), for a total consumer surplus of $9. Thus consumer surplus rises by $5 (which is the size of area B) when the price of a bottle of water falls from $4 to $2.5. a.Figure 10b. When the price of a bottle of water is $4, Ernie sells two bottles of water. His producer surplus is shown as area A in the figure. He receives $4 for his first bottle of water, but it costs only $1 to produce, so Ernie has producer surplus of $3. He also receives $4 for his second bottle of water, which costs $3 to produce, so he has producer surplus of $1. Thus Ernie’s total producer surplus is $3 + $1 = $4, which is the area of A in the figure.c. When the price of a bottle of water rises from $4 to $6, Ernie sells three bottles of water, an increase of one. His producer surplus consists of both areas A and B in the figure, an increase by the amount of area B. He gets producer surplus of $5 from the first bottle ($6 price minus $1 cost), $3 from the second bottle ($6 price minus $3 cost), and $1 from the third bottle ($6 price minus $5 price), for a total producer surplus of $9. Thus producer surplus rises by $5 (which is the size of area B) when the price of a bottle of water rises from $4 to $6.6. a. From Ernie’s supply schedule and Bert’s demand schedule, the quantityequilibrium quantity of two.b. At a price of $4, consumer surplus is $4 and producer surplus is $4, as shown in Problems 3 and 4 above. Total surplus is $4 + $4 = $8.c. If Ernie produced one less bottle, his producer surplus would decline to $3, as shown in Problem 4 above. If Bert consumed one less bottle, his consumer surplus would decline to $3, as shown in Problem 3 above. So total surplus would decline to $3 + $3 = $6.d. If Ernie produced one additional bottle of water, his cost would be $5, but the price is only $4, so his producer surplus would decline by $1. If Bert consumed one additional bottle of water, his value would be $3, but the price is $4, so his consumer surplus would decline by $1. So total surplus declines by $1 + $1 = $2.7. a. The effect of falling production costs in the market for stereos results in a shift to the right in the supply curve, as shown in Figure 11. As a result, the equilibrium price of stereos declines and the equilibrium quantity increases.Figure 11b. The decline in the price of stereos increases consumer surplus from area A to A + B + C + D, an increase in the amount B + C + D. Prior to the shift in supply, producer surplus was areas B + E (the area above the supply curve and below the price). After the shift in supply, producer surplus is areas E + F + G. So producer surplus changes by the amount F + G – B, which may be positive or negative. The increase in quantity increases producer surplus, while the decline in the price reduces producer surplus. Because consumer surplus rises by B + C + D and producer surplus rises by F + G – B, total surplus rises by C + D + F + G.c. If the supply of stereos is very elastic, then the shift of the supply curve benefits consumers most. To take the most dramatic case, suppose the supply curve were horizontal, as shown in Figure 12. Then there is no producer surplus at all. Consumers capture all the benefits of falling production costs, with consumer surplus rising from area A to area A + B.Figure 128. Figure 13 shows supply and demand curves for haircuts. Supply equals demand at a quantity of three haircuts and a price between $4 and $5. Firms A, C, and D should cut the hair of Ellen, Jerry, and Phil. Oprah’s willingness to pay is too low and firm B’s costs are too high, so they do not participate. The maximum total surplus is the area between the demand and supply curves, which totals $11 ($8 value minus $2 cost for the first haircut, plus $7 value minus $3 cost for the second, plus $5 value minus $4 cost for the third).Figure 139. a. The effect of falling production costs in the market for computers results in a shift to the right in the supply curve, as shown in Figure 14. As a result, the equilibrium price of computers declines and the equilibrium quantity increases. The decline in the price of computers increases consumer surplus from area A to A + B + C + D, an increase in the amount B + C + D.Figure 14 Figure 15Prior to the shift in supply, producer surplus was areas B + E (the area above thesupply curve and below the price). After the shift in supply, producer surplus isareas E + F + G. So producer surplus changes by the amount F + G – B, whichmay be positive or negative. The increase in quantity increases producer surplus,while the decline in the price reduces producer surplus. Because consumer surplusrises by B + C + D and producer surplus rises by F + G – B, total surplus rises byC +D + F + G.b. Because typewriters are substitutes for computers, the decline in the price of computers means that people substitute computers for typewriters, shifting the demand for typewriters to the left, as shown in Figure 15. The result is a decline in both the equilibrium price and equilibrium quantity of typewriters. Consumer surplus in the typewriter market changes from area A + B to A + C, a net change of C – B. Producer surplus changes from area C + D + E to area E, a net loss of C + D. Typewriter producers are sad about technological advances in computers because their producer surplus declines.c. Because software and computers are complements, the decline in the price and increase in the quantity of computers means that the demand for software increases, shifting the demand for software to the right, as shown in Figure 16. The result is an increase in both the price and quantity of software. Consumer surplus in the software market changes from B + C to A + B, anet change of A – C. Producer surplus changes from E to C + D + E, an increase of C + D, so software producers should be happy about the technological progress in computers.Figure 16d. Yes, this analysis helps explain why Bill Gates is one the world’s richest people, because his company produces a lot of software that is a complement with computers and there has been tremendous technological advance in computers.10. a. With Provider A, the cost of an extra minute is $0. With Provider B, the cost of anextra minute is $1.b. With Provider A, my friend will purchase 150 minutes [= 150 – (50)(0)]. WithProvider B, my friend would purchase 100 minutes [= 150 – (50)(1)].c. With Provider A, he would pay $120. The cost would be $100 with Provider B.Figure 17d. Figure 17 shows the friend’s demand. With Provider A, he buys 150 minutes andhis consumer surplus is equal to (1/2)(3)(150) – 120 = 105. With Provider B, hisconsumer surplus is equal to (1/2)(2)(100) = 100.e. I would recommend Provider A because he receives greater consumer surplus.11. a. Figure 18 illustrates the demand for medical care. If each procedure has a price of $100, quantity demanded will be Q1 procedures.Figure 18b. If consumers pay only $20 per procedure, the quantity demanded will be Q2 procedures. Because the cost to society is $100, the number of procedures performed is too large to maximize total surplus. The quantity that maximizes total surplus is Q1 procedures, which is less than Q2.c. The use of medical care is excessive in the sense that consumers get procedures whose value is less than the cost of producing them. As a result, the economy’s total surplus is reduced.d. To prevent this excessive use, the consumer must bear the marginal cost of the procedure. But this would require eliminating insurance. Another possibility would be that the insurance company, which pays most of the marginal cost of the procedure ($80, in this case) could decide whether the procedure should be performed. But the insurance company does not get the benefits of the procedure, so its decisions may not reflect the value to the consumer.。

微观经济学部分练习题参考答案第一单元：经济学概述、供求与局部均衡练习题一、单选题1.说“资源是稀缺的”是指BA世界上大多数人生活在贫困中 B.相对于资源的需求而言，资源总是不足的C.资源必须保留给下一代D.世界上资源最终将由于生产更多的物品和劳务而消耗光2.经济物品是指DA.有用的物品B.稀缺的物品C.要用钱购买的物品D.有用且稀缺的物品3.经济学可定义为CA.政府对市场制度的干预B.企业取得利润的活动C.研究如何最合理地配置稀缺资源于诸多用途D.人们靠收入生活4.从经济学的观点看，资源配置问题说明的是CA.人们的需要是多方面的且是无止境的B.资源的供给是有限的C.一种资源有许多可供选择的用途，但有一种利用效果最佳D.以上说法都对5.下列命题中那一个不是实证经济学命题 CA.昨日中国人民银行宣布把存款基准利率降低0.25%B.2011年失业率超过8%C.个人所得税对中等收入家庭是不公平的D.个人所得税的起征点提高了6.某人有10万元资金，可供选择的用途及各种用途能获得的收入是：开饭店获利3万元，炒股票获利3.5万元，进行期货投机获利4万元。

该人选择期货投机的机会成本为AA.13.5万元B.20.5万元C.14万元D.13万元7.保持所有其他因素不变，某种商品的价格下降，将导致CA.需求增加B.需求减少C.需求量增加D.需求量减少8.在某种物品价格上升的百分比既定时，引起需求量减少最大的情况是CA.价格上升后时间长B.这种物品的支出在收入中占的比例大C.很容易得到替代品D.以上全对9.如果某种物品小幅度降价会引起需求量大幅度变动，那么，该物品BA.需求缺乏弹性B.需求富有弹性C.需求单位弹性D.需求价格弹性接近于零10.一条垂直的需求曲线所表示的是DA.单位弹性B.无限弹性C.富有弹性D.需求的价格弹性为零11.下面哪一种物品的需求价格弹性最大BA.大米B.点心C.蔬菜D.三种物品相同12.假定某商品的价格从9元下降到8元，需求量从50增加到60，需求为BA.缺乏弹性B.富有弹性C.单位弹性D.不能确定13.某商品的价格从5元下降到4元，需求量增加了100，需求为DA.缺乏弹性B.富有弹性C.单位弹性D.不能确定14.下列哪种情况使总收益下降BA.价格上升，需求缺乏弹性B.价格上升，需求富有弹性C.价格下降，需求富有弹性D.价格上升，供给富有弹性15.已知某两种商品的交叉弹性等于1.8，则这两种商品是BA.无关品B.替代品C.互补品D.完全补充品16.在现行价格不变时，如果收入增加的百分比较大而需求量减少的百分比较小，那么DA.需求必定富有价格弹性B.需求必定缺乏价格弹性C.所涉及的是正常物品D.所涉及的是低档物品17.收入增加10%引起现行价格下需求量减少5%，收入弹性是BA.0.5B.－0.5C.2.0D.－2.018.小李的月收入从950元增加到1050元，结果他决定每月看电影的次数增加一倍，小李对电影的需求CA.富有价格弹性B.缺乏价格弹性C.富有收入弹性D.缺乏收入弹性19.如果沙特王国认为石油输出国组织石油供给量增加会增加石油销售总收益，那么，沙特人就一定相信石油的需求CA.收入缺乏弹性B.收入富有弹性C.价格富有弹性D.价格缺乏弹性20.如果A物品与B物品是替代品，那么CA.A与B之间需求的交叉弹性是零B. A与B之间需求的交叉弹性是负值C.A与B之间需求的交叉弹性是正值D.它们的需求收入弹性都是负值21.假定汉堡包与炸薯条之间的需求交叉弹性为负值，那么BA.汉堡包价格上升将引起炸薯条的均衡价格上升B.汉堡包价格上升将引起炸薯条的均衡价格下降C.汉堡包价格上升对炸薯条的均衡价格没有影响D.它们是替代品22.长期供给弹性DA.比即时供给富有弹性，但比短期供给缺乏弹性B.比即时供给与短期供给都缺乏弹性C.比即时供给缺乏弹性，但比短期供给富有弹性D.比即时供给与短期供给都富有弹性23.某消费者的收入下降，而他对某商品的需求却增加，该商品为AA.低档商品B.替代商品C.互补商品D.一般商品24.若某产品的供给弹性无穷大，当该产品的需求增加时，则CA均衡价格和均衡产量同时增加 B.均衡价格和均衡产量同时减少C.均衡产量增加但价格不变D.均衡价格上升但产量不变25.垂直的供给曲线表示BA.在一固定的价格无限制地提供某种产品B.价格的变化对供给量没有影响C.价格与供给量成反方向变化D.该行业被垄断26.斜直线型需求曲线的弹性为CA.曲线上各点的弹性都相同B.在高的价格段缺乏弹性，在低的价格段富有弹性C.在高的价格段富有弹性，在低的价格段缺乏弹性D.在某些点上为单位弹性27.某商品价格下降导致其互补品的BA.需求曲线向左移动B.需求曲线向右移动C.供给曲线向右移动D.价格上升28.某商品的需求曲线向下倾斜，如果该商品的价格从3元下降到2.75元，则DA.该商品需求下降B.该商品需求上升C.该商品需求量下降D.该商品需求量上升29.下列不会引起牛排需求发生变化的情况为AA.牛排价格从每斤20元上升到每斤22元B.牛的饲养者宣传牛排中富含维生素C.医生说多吃牛肉有损健康D.汉堡包价格从每个12元下降到10元30.如果甲产品价格下降引起乙产品需求曲线向右移动，那么BA.甲和乙是互替商品B.甲和乙是互补商品C.甲为低档商品，乙为高档商品D.甲为高档商品，乙为低档商品31.商品需求量随着价格的下降而上升，这是因为CA.价格下降导致供给下降B.价格下降使需求曲线右移C.人们实际收入的提高增加了对商品的消费D.为获得均衡，价格下降后需求必须增加32.收入和偏好是BA.影响供给的因素B.影响需求的因素C.在经济分析中可以忽略D.上述都不正确33.随着奶油均衡价格的下降AA.人造奶油的需求曲线向左下移动B.人造奶油的需求曲线向右上移动C.人造奶油的供给曲线向左下移动D.人造奶油的供给曲线向右上移动34.若小麦的需求曲线向右上移动，那将DA.导致小麦价格的下降B.不会改变小麦的产量C.导致小麦供给的增加而减少其它商品的供给D.导致玉米的供给量增加35.斜直线型需求曲线的斜率不变，因此其价格弹性也不变。

曼昆《经济学原理（微观经济学分册）》（第7版）课后习题详解第1章经济学十大原理一、概念题1．稀缺性（scarcity）答：经济学研究的问题和经济物品都是以稀缺性为前提的。

稀缺性指在给定的时间内，相对于人的需求而言，经济资源的供给总是不足的，也就是资源的有用性与有限性。

人类消费各种物品的欲望是无限的，满足这种欲望的物品，有的可以不付出任何代价而随意取得，称之为自由物品，如阳光和空气；但绝大多数物品是不能自由取用的，因为世界上的资源（包括物质资源和人力资源）是有限的，这种有限的、为获取它必须付出某种代价的物品，称为“经济物品”。

正因为稀缺性的客观存在，地球上就存在着资源的有限性和人类的欲望与需求的无限性之间的矛盾。

经济学的一个重要研究任务就是：“研究人们如何进行抉择，以便使用稀缺的或有限的生产性资源（土地、劳动、资本品如机器、技术知识）来生产各种商品，并把它们分配给不同的社会成员进行消费。

”也就是从经济学角度来研究使用有限的资源来生产什么、如何生产和为谁生产的问题。

2．经济学（economics）答：经济学是研究如何将稀缺的资源有效地配置给相互竞争的用途，以使人类的欲望得到最大限度满足的科学。

时下经常见诸国内报刊文献的“现代西方经济学”一词，大多也都在这个意义上使用。

自从凯恩斯的名著《就业、利息和货币通论》于1936年发表之后，西方经济学界对经济学的研究便分为两个部分：微观经济学与宏观经济学。

微观经济学是以单个经济主体（作为消费者的单个家庭或个人，作为生产者的单个厂商或企业，以及单个产品或生产要素市场）为研究对象，研究单个经济主体面对既定的资源约束时如何进行选择的科学。

宏观经济学则以整个国民经济为研究对象，主要着眼于对经济总量的研究。

3．效率（efficiency）答：效率指人们在实践活动中的产出与投入之比值，或者是效益与成本之比值，如果比值大，效率就高；反之，比值小，效率就低。

效率与产出或者收益的大小成正比，而与成本或投入成反比，也就是说，如果想提高效率，必须降低成本或投入，提高收益或产出。

曼昆微观经济学课后答案 Last revision date: 13 December 2020.第二篇市场如何运作第四章供给与需求的市场力量复习题1．什么是竞争市场？简单描述一种不是完全竞争的市场。

答：竞争市场是有许多买者与卖者，以至于每个人对市场价格的影响都微乎其微的市场。

除了完全竞争市场之外，还有垄断市场。

在这个市场上只有一个卖者，他决定价格。

这个卖者被称为垄断者。

还有寡头市场，在这个市场上有几个并不总是主动竞争的卖者，他们提供相似或相同的产品。

通常情况下，寡头们会尽力联合起来，避免激烈的竞争，收取较高的市场价格。

还有垄断竞争市场，这是一个有许多提供相似但不相同产品的企业的市场结构。

由于各自提供的产品不同，每个企业对产品的价格都有一定的影响力。

2．什么因素决定买者对一种物品的需求量?答：物品的价格、买者的收入水平、相关物品的价格、买者的偏好和对物品的价格预期。

3．什么是需求表和需求曲线它们之间是什么关系为什么需求曲线向右下方倾斜答：需求表是表示一种物品价格与需求量之间关系的表格，需求曲线是表示一种物品价格与需求量之间关系的图形。

需求曲线将需求表用图形的形式表现出来，需求表是需求曲线上若干个点的坐标的数字表格排列。

需求曲线向右下方倾斜是因为在其他条件不变的情况下，随着价格上升，需求量会减少。

4．消费者嗜好的变化引起了沿着需求曲线的变动，还是需求曲线的移动？价格的变化引起了沿着需求曲线的变动，还是需求曲线的移动?答：消费者嗜好的变化引起了需求曲线的移动，价格的变化引起了沿着需求曲线的变动。

5．Popeye的收入减少了，结果他买了更多的菠菜。

菠菜是低档物品，还是正常物品？Popeye 的菠菜需求14曲线会发生什么变化?答：根据低档物品的定义，菠菜对Popeye 来说是低档物品。

因为Popeye 的收入减少了，他对菠菜的需求量反而增大了。

对于低档物品来说，需求曲线是向右下方倾斜的，收入增加会引起需求曲线向外移动。

曼昆《经济学原理（微观经济学分册）》课后习题及详解（微观经济学前沿）【圣才出品】第22章微观经济学前沿⼀、概念题1．道德风险（moral hazard）答：道德风险指⼀个没有受到完全监督的⼈从事不忠诚或不合意⾏为的倾向。

换句话说，道德风险是在双⽅信息⾮对称的情况下，⼈们享有⾃⼰⾏为的收益，⽽将成本转嫁给别⼈，从⽽造成他⼈损失的可能性。

道德风险的存在不仅使得处于信息劣势的⼀⽅受到损失，⽽且会破坏原有的市场均衡，导致资源配置的低效率。

在信息不对称的情况下，当代理⼈为委托⼈⼯作⽽其⼯作成果同时取决于代理⼈所做的主观努⼒和不由主观意志决定的各种客观因素，并且主观原因对委托⼈来说难以区别时，就会产⽣代理⼈隐瞒⾏动⽽导致对委托⼈利益损害的“道德风险”。

道德风险发⽣的⼀个典型领域是保险市场。

解决道德风险的主要⽅法是风险分担。

2．代理⼈（agent）答：代理⼈指⼀个为委托⼈完成某种⾏为的⼈。

这⾥的“⼈”，可以是⾃然⼈或法⼈。

在现实经济⽣活中，代理⼈的种类很多，如销售代理商、企业代理商、专利代理⼈、⼴告代理⼈、保险代理⼈、税务代理⼈等。

在现代微观经济学中，企业的管理者可以被看成是所有者的代理⼈。

随着分⼯和专业化的发展，交易和契约活动中的委托—代理关系成为现代经济中的重要问题。

在公司制度中，由于所有权和控制权、经营权的分离，导致了所有者和管理者之间潜在的利益⽭盾。

特别是在⼀些⼤型股份公司⾥，如果股权极其分散，对管理者的控制和影响就更弱了。

管理者是为了⾃⼰的利益最⼤化⽽⼯作，⽽不是为了股东利益最⼤化。

⽽委托—代理问题的重要之处在于，由于代理⼈的某些信息或某些⾏动是不可观察的，或者虽然可观察但不可确证，委托⼈难以通过⼀个直接的强制性契约来实现⾃⼰的利益最⼤化，⽽只能通过⼀个间接的激励⽅案，使代理⼈在追求⾃我利益的最⼤化实现的同时，也使委托⼈的利益尽可能地得到实现。

3．委托⼈（principal）答：委托⼈指让代理⼈完成某种⾏为的⼈。

Ch1.绪论一、名词解释二、问答题1.微观经济学研究家庭和企业如何作出决策以及这些这些决策在市场上的相互作用。

微观经济学的中心原理是家庭和企业的最优化——他们在目的和所面临的约束条件下可以让自己的景况更好。

而相对的，宏观经济学研究经济的整体情况，它主要关心总产出、总就业、一般物件水平和国际贸易等问题，以及这些宏观指标的波动趋势与规律。

应该看到，宏观经济学研究的这些宏观经济变量是以经济体系中千千万万个体家庭和企业之间的相互作用所构成的。

因此，微观经济决策总是构成宏观经济模型的基础，宏观经济学必然依靠微观经济基础。

2.一般的，模型是对某些具体事物的抽象，经济模型也是如此。

经济模型可以简洁、直接地描述所要研究的经济对象的各种关系。

这样，经济学家可以依赖模型对特定的经济问题进行研究；并且，由于经济实际不可控，而模型是可控的，经济学家可以根据研究需要，合理、科学的调整模型来研究各种经济情况。

另外，经济模型一般是数学模型，而数学是全世界通用的科学语言，使用规范、标准的经济模型也有利于经济学家正确表达自己的研究意图，便于学术交流。

3.略。

请结合您目前所搜集的最新宏观经济新闻进行讨论。

4.市场出清模型就是供给与需求可以在价格机制调整下很快达到均衡的模型。

市场出清模型的前提条件是价格是具有伸缩性的（或弹性）。

但是，我们知道，价格具有伸缩性是一个很强的假设，在很多实际情况下，这个假设都是不现实的。

比如：劳动合同会使劳动力价格在一段时期内具有刚性。

因此，我们必须考虑什么情况下价格具有伸缩性是合适的。

现在一般地认为，在研究长期问题时，假设价格具有伸缩性是合理的；而在研究短期问题时，最好假设价格具有刚性。

因为，从长期看，价格机制终将发挥作用，使市场供需平衡，即市场出清，而在短期，价格机制因其他因素制约，难以很快使市场出清。

5.一般的，人们认为科学的定义是：一种建立稳定关系的科学的研究方法。

比如：物理学家可以通过实验来收集数据，证明或推翻一个假设。

曼昆《经济学原理（微观经济学分册）》（第6版）第2章像经济学家一样思考课后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。

一、概念题1．循环流量图（circular flow diagram）答：循环流量图是指表明物品和劳务、生产要素以及货币支付在家庭和企业之间如何流动的经济图形，如图2-1所示。

在这个模型中，经济由两类决策者——家庭和企业——所组成。

企业用劳动、土地和资本（建筑物和机器等）这些投入来生产物品和劳务，这些投入被称为生产要素。

家庭则拥有生产要素并消费企业生产的所有物品与劳务。

图2-1 循环流量图图2-1中，经济决策由家庭和企业做出。

家庭和企业在物品与劳务市场（在这个市场上，家庭是买者而企业是卖者）以及生产要素市场（在这个市场上，企业是买者而家庭是卖者）上相互交易。

外面一圈的箭头表示货币的流向，里面一圈的箭头表示相应的物品与劳务的流向。

循环流量图的形式是简化的，是整体经济的一个简化模型，因为它不包括国际贸易和政府。

2．生产可能性边界（production possibilities frontier）（深圳大学2007研；北京工业大学2008研）答：生产可能性边界也称为社会生产可能性边界或生产可能性曲线，指一个经济在可获得的生产要素与生产技术既定时所能生产的产品的产量的各种组合。

由于整个社会的经济资源是有限的，当这些经济资源都被充分利用时，增加一定量的一种产品的生产，就必须放弃一定量的另一种产品的生产。

整个社会生产的选择过程形成了一系列的产品间的不同产量组合，所有这些不同产量的组合就构成了社会生产的可能性边界。

Interdependence and the Gains from TradeWHAT’S NEW IN THE THIRD EDITION:The discussion of gains from trade and comparative advantage has been rewritten for improved clarity.LEARNING OBJECTIVES:By the end of this chapter, students should understand:how everyone can benefit when people trade with one another.the meaning of absolute advantage and comparative advantage.how comparative advantage explains the gains from trade.how to apply the theory of comparative advantage to everyday life and national policy.CONTEXT AND PURPOSE:Chapter 3 is the third chapter in the three chapter section that serves as the introduction of the text. The first chapter introduced ten fundamental principles of economics. The second chapter developed how economists approach problems. This chapter shows how people and countries gain from trade (which is one of the ten principles discussed in Chapter 1). The purpose of Chapter 3 is to demonstrate how everyone can gain from trade. Trade allows people to specialize in the production of goods for which they have a comparative advantage and then trade for goods other people produce. Because of specialization, total output rises and through trade we are all able to share in the bounty. This is as true for countries as it is for individuals. Since everyone can gain from trade, restrictions on trade tend to reduce welfare.KEY POINTS:1. Each person consumes goods and services produced by many other people both in our country andaround the world. Interdependence and trade are desirable because they allow everyone to enjoy a greater quantity and variety of goods and services.3INTERDEPENDENCE AND THEGAINS FROM TRADE36 Chapter 3/Interdependence and the Gains from Trade2.There are two ways to compare the ability of two people in producing a good. The person who canproduce the good with a smaller quantity of inputs is said to have an absolute advantage inproducing the good. The person who has the smaller opportunity cost of producing the good is said to have a comparative advantage. The gains from trade are based on comparative advantage, not absolute advantage.3.Trade makes everyone better off because it allows people to specialize in those activities in whichthey have a comparative advantage.4.The principle of comparative advantage applies to countries as well as people. Economists use theprinciple of comparative advantage to advocate free trade among countries.CHAPTER OUTLINE:I. A Parable for the Modern EconomyA. Example: two goods—meat and potatoes and two people—a cattle rancher and a potatofarmer (each of whom like to consume both potatoes and meat).1. The gains from trade are obvious if the farmer can only grow potatoes and therancher can only raise cattle.2. The gains from trade are also fairly obvious if, instead, the farmer can raisecattle as well as grow potatoes, but he is not as good at it and the rancher cangrow potatoes in addition to raising cattle, but her land is not well suited for it.3. The gains from trade are not as clear if either the farmer or the rancher is betterat producing both potatoes and meat.B. Production Possibilities1. The farmer and rancher both work 8 hours per day and can use this time togrow potatoes, raise cattle, or both.Chapter 3/Interdependence and the Gains from Trade 372.Table 1 shows the amount of time each takes to produce 1 ounce of either good:3.The production possibilities can also be graphed.a.These production possibilities frontiers are drawn linearly instead of being bowed out. This assumes that the farmer's and the rancher's technology for producing meat and potatoes allows them to switch between producing one good and the other at a constant rate.b.As we saw in Chapter 2, these production possibilities frontiers represent the principles of tradeoffs and opportunity costs.4.We will assume that the farmer and rancher divide their time equally between raising cattle and growing potatoes.38 Chapter 3/Interdependence and the Gains from Tradea. The farmer produces (and consumes) at point A—16 ounces of potatoesand 4 ounces of meat.b. The rancher produces (and consumes) at point B—24 ounces of potatoesand 12 ounces of meat.C. Specialization and Trade1. Suppose the rancher suggests that the farmer specialize in the production ofpotatoes and then trade with the rancher for meat.a. The rancher will spend 6 hours a day producing meat (18 ounces) and 2hours a week growing potatoes (12 ounces).b. The farmer will spend 8 hours a day growing potatoes (32 ounces).c. The rancher will trade 5 ounces of meat for 15 ounces of potatoes.Chapter 3/Interdependence and the Gains from Trade 392. End results:a.The rancher produces 18 ounces of meat and trades 5 leaving him with 13 ounces of meat. He also grows 12 ounces of potatoes and receives 15 ounces in the trade, leaving him with 27 ounces of potatoes.b.The farmer produces 32 ounces of potatoes and trades 15 leaving him with 17 ounces. He also receives 5 ounces of meat in the trade with the rancher.3.In both cases, they are able to consume quantities of potatoes and meat after the trade that they could not reach before the trade.II. The Principle of Comparative Advantage A.Absolute Advantage 1.Definition of absolute advantage: the comparison among producers of a good according to their productivity.2.The rancher has an absolute advantage in the production of both potatoes and meat.B.Opportunity Cost and Comparative Advantage1.Definition of opportunity cost: whatever must be given up to obtain some item.40 Chapter 3/Interdependence and the Gains from Tradea. For the rancher, the opportunity cost of producing an ounce of potatoesis ½ ounce of meat (because it takes 10 minutes to produce 1 ounce ofpotatoes).b. For the farmer, the opportunity cost of producing 1 ounce of potatoes isonly ¼ ounce of meat (because it takes 15 minutes to produce 1 ounceof potatoes).c. The opportunity cost of producing 1 ounce of meat is the inverse of theopportunity cost of producing 1 ounce of potatoes.2. Definition of comparative advantage: the comparison among producersof a good according to their opportunity cost.a. The farmer has a lower opportunity cost of producing potatoes andtherefore has a comparative advantage in the production of potatoes.b. The rancher has a lower opportunity cost of producing meat andtherefore has a comparative advantage in the production of meat.3. Because the opportunity cost of producing one good is the inverse of theopportunity cost of producing the other, it is impossible for a person to have acomparative advantage in the production of both goods.C. Comparative Advantage and Trade1. When specialization in a good occurs (assuming there is a comparativeadvantage), total output will grow.2. As long as the opportunity cost of producing the goods differs across the twoindividuals, both can gain from specialization and trade.a. The rancher buys 15 ounces of potatoes for 5 ounces of meat. The priceof each ounce of potatoes is 1/3 ounce of meat. This is lower than therancher's opportunity cost of ½ ounce of meat and is thereforebeneficial to the rancher.b. The farmer buys 5 ounces of meat with 15 ounces of potatoes. Thisimplies that the price of each ounce of meat is 3 ounces of potatoes,which is lower than the farmer's opportunity cost of 4 ounces of potatoes.Thus, trade also benefits the farmer.Chapter 3/Interdependence and the Gains from Trade 41III. FYI: The Legacy of Adam Smith and David RicardoA. In Adam Smith's 1776 book An Inquiry into the Nature and Causes of the Wealth ofNations, he writes of the ability of producers to benefit through specialization and trade.B. In David Ricardo's 1817 book Principles of Political Economy and Taxation, Ricardodevelops the theory of comparative advantage and argues against restrictions on freetrade.C. The benefits of free trade are an issue that is generally agreed upon by most economists,and the theories and arguments developed by these two individuals 200 years ago arestill used today.IV. Applications of Comparative AdvantageA. Should Tiger Woods Mow His Own Lawn?1. Given Wood's athleticism, it is entirely possible that he could mow his lawn fasterthan most men.2. This implies that he has an absolute advantage.42 Chapter 3/Interdependence and the Gains from Trade3. However, if the opportunity cost of his time is $10,000 (his pay to film acommercial for Nike), it is likely that someone else will have a comparativeadvantage in mowing his lawn.4. Both he and the person hired will be better off as long as he pays the individualmore than the individual's opportunity cost and less than $10,000.B. Should the United States Trade with Other Countries?1. Just as individuals can benefit from specialization and trade, so can thepopulations of different countries.2. Definition of imports: goods produced abroad and sold domestically.3. Definition of exports: goods produced domestically and sold abroad.4. The principle of comparative advantage suggests that each good should beproduced by the country with a comparative advantage in producing that good(smaller opportunity cost).5. Through specialization and trade, countries can have more of all goods toconsume.6. Trade issues among nations are more complex. Individuals can be made worseoff even when the country as a whole is made better off.C. In the News: Who Has a Comparative Advantage in Producing Lamb?1. A tariff is a tax on an imported product, used to lower the quantity of specificimports.2. This is an opinion column from The Wall Street Journal on the use of tariffs inthe lamb industry.Chapter 3/Interdependence and the Gains from Trade 4344 Chapter 3/Interdependence and the Gains from TradeSOLUTIONS TO TEXT PROBLEMS:Quick Quizzes1. Figure 1 shows a production possibilities frontier for Robinson Crusoe between gatheringcoconuts and catching fish. If Crusoe lives by himself, this frontier limits his consumption ofcoconuts and fish, but if he can trade with natives on the island he will be able to consume at a point outside his production possibilities frontier.Figure 12. Crusoe’s opportunity cost of catching one fish is 10 coconuts, since he can gather 10 coconuts inthe same amount of time it takes to catch one fish. Friday’s opportunity cost of catching one fish is 15 coconuts, since he can gather 30 coconuts in the same amount of time it takes to catch two fish. Friday has an absolute advantage in catching fish, since he can catch two per hour, whileCrusoe can only catch one per hour. But Crusoe has a comparative advantage in catching fish,since his opportunity cost of catching a fish is less than Friday’s.3. If the world’s fastest typist happens to be trained in brain surgery, he should hire a secretary.He has an absolute advantage in typing, but a comparative advantage in brain surgery, since his opportunity cost in brain surgery is low compared to the opportunity cost for other people.Questions for Review1. Absolute advantage reflects a comparison of the productivity of one person, firm, or nation tothat of another, while comparative advantage is based on the relative opportunity costs of thepersons, firms, or nations. While a person, firm, or nation may have an absolute advantage inproducing every good, they can't have a comparative advantage in every good.2. Many examples are possible. Suppose, for example, that Roger can prepare a fine meal of hotdogs and macaroni in just ten minutes, while it takes Anita twenty minutes. And Roger can do all the wash in three hours, while it takes Anita four hours. Roger has an absolute advantage inboth cooking and doing the wash, but Anita has a comparative advantage in doing the wash (the wash takes the same amount of time as 12 meals, while it takes Roger 18 meals' worth of time).3. Comparative advantage is more important for trade than absolute advantage. In the example inproblem 2, Anita and Roger will complete their chores more quickly if Anita does at least some of the wash and Roger cooks the fine meals for both, because Anita has a comparative advantagein doing the wash, while Roger has a comparative advantage in cooking.4. A nation will export goods for which it has a comparative advantage because it has a smalleropportunity cost of producing those goods. As a result, citizens of all nations are able toconsume quantities of goods that are outside their production possibilities frontiers.5. Economists oppose policies that restrict trade among nations because trade allows all countriesto achieve greater prosperity by allowing them to receive the gains from comparative advantage.Restrictions on trade hurt all countries.Problems and Applications1. In the text example of the farmer and the rancher, the farmer's opportunity cost of producingone ounce of meat is 4 ounces of potatoes because for every 8 hours of work, he can produce 8 ounces of meat or 32 ounces of potatoes. With limited time at his disposal, producing an ounce of meat means he gives up the opportunity to produce 4 ounces of potatoes. Similarly, therancher's opportunity cost of producing one ounce of meat is 2 ounces of potatoes because forevery 8 hours of work, she can produce 24 ounces of meat or 48 ounces of potatoes. Withlimited time at her disposal, producing an ounce of meat means she gives up the opportunity to produce 2 ounces of potatoes.2. a. See Figure 2. If Maria spends all five hours studying economics, she can read 100 pages,so that is the vertical intercept of the production possibilities frontier. If she spends allfive hours studying sociology, she can read 250 pages, so that is the horizontal intercept.The time costs are constant, so the production possibilities frontier is a straight line.Figure 2b. It takes Maria two hours to read 100 pages of sociology. In that time, she could read 40pages of economics. So the opportunity cost of 100 pages of sociology is 40 pages ofeconomics.3. a.b. See Figure 3. With 100 million workers and four cars per worker, if either economy weredevoted completely to cars, it could make 400 million cars. Since a U.S. worker canproduce 10 tons of grain, if the United States produced only grain it would produce 1,000million tons. Since a Japanese worker can produce 5 tons of grain, if Japan producedonly grain it would produce 500 million tons. These are the intercepts of the productionpossibilities frontiers shown in the figure. Note that since the tradeoff between cars andgrain is constant, the production possibilities frontier is a straight line.Figure 3c. Since a U.S. worker produces either 4 cars or 10 tons of grain, the opportunity cost of 1car is 2½ tons of grain, which is 10 divided by 4. Since a Japanese worker produceseither 4 cars or 5 tons of grain, the opportunity cost of 1 car is1 1/4 tons of grain, which is 5 divided by 4. Similarly, the U.S. opportunity cost of 1 tonof grain is 2/5 car (4 divided by 10) and the Japanese opportunity cost of 1 ton of grainis 4/5 car (4 divided by 5). This gives the following table:d. Neither country has an absolute advantage in producing cars, since they're equallyproductive (the same output per worker); the United States has an absolute advantagein producing grain, since it is more productive (greater output per worker).e. Japan has a comparative advantage in producing cars, since it has a lower opportunitycost in terms of grain given up. The United States has a comparative advantage inproducing grain, since it has a lower opportunity cost in terms of cars given up.f. With half the workers in each country producing each of the goods, the United Stateswould produce 200 million cars (that is 50 million workers times 4 cars each) and 500million tons of grain (50 million workers times 10 tons each). Japan would produce 200million cars (50 million workers times 4 cars each) and 250 million tons of grain (50million workers times 5 tons each).g. From any situation with no trade, in which each country is producing some cars andsome grain, suppose the United States changed 1 worker from producing cars toproducing grain. That worker would produce 4 fewer cars and 10 additional tons of grain.Then suppose the United States offers to trade 7 tons of grain to Japan for 4 cars. TheUnited States will do this because it values 4 cars at 10 tons of grain, so it will be betteroff if the trade goes through. Suppose Japan changes 1 worker from producing grain toproducing cars. That worker would produce 4 more cars and 5 fewer tons of grain.Japan will take the trade because it values 4 cars at 5 tons of grain, so it will be betteroff. With the trade and the change of 1 worker in both the United States and Japan,each country gets the same amount of cars as before and both get additional tons ofgrain (3 for the United States and 2 for Japan). Thus by trading and changing theirproduction, both countries are better off.4. a. Pat's opportunity cost of making a pizza is 1/2 gallon of root beer, since she could brew1/2 gallon in the time (2 hours) it takes her to make a pizza. Pat has an absoluteadvantage in making pizza since she can make one in two hours, while it takes Kris fourhours. Kris' opportunity cost of making a pizza is 2/3 gallons of root beer, since shecould brew 2/3 of a gallon in the time (4 hours) it takes her to make a pizza. Since Pat'sopportunity cost of making pizza is less than Kris's, Pat has a comparative advantage inmaking pizza.b. Since Pat has a comparative advantage in making pizza, she will make pizza andexchange it for root beer that Kris makes.c. The highest price of pizza in terms of root beer that will make both roommates better offis 2/3 of a gallon of root beer. If the price were higher than that, then Kris would prefermaking her own pizza (at an opportunity cost of 2/3 of a gallon of root beer) rather thantrading for pizza that Pat makes. The lowest price of pizza in terms of root beer that willmake both roommates better off is 1/2 gallon of root beer. If the price were lower thanthat, then Pat would prefer making her own root beer (she can make 1/2 gallon of rootbeer instead of making a pizza) rather than trading for root beer that Kris makes.5. a. Since a Canadian worker can make either two cars a year or 30 bushels of wheat, theopportunity cost of a car is 15 bushels of wheat. Similarly, the opportunity cost of abushel of wheat is 1/15 of a car. The opportunity costs are the reciprocals of each other.b. See Figure 4. If all 10 million workers produce two cars each, they produce a total of 20million cars, which is the vertical intercept of the production possibilities frontier. If all 10million workers produce 30 bushels of wheat each, they produce a total of 300 millionbushels, which is the horizontal intercept of the production possibilities frontier. Sincethe tradeoff between cars and wheat is always the same, the production possibilitiesfrontier is a straight line.If Canada chooses to consume 10 million cars, it will need 5 million workers devoted tocar production. That leaves 5 million workers to produce wheat, who will produce a totalof 150 million bushels (5 million workers times 30 bushels per worker). This is shown aspoint A on Figure 4.c. If the United States buys 10 million cars from Canada and Canada continues to consume10 million cars, then Canada will need to produce a total of 20 million cars. So Canadawill be producing at the vertical intercept of the production possibilities frontier. But ifCanada gets 20 bushels of wheat per car, it will be able to consume 200 million bushelsof wheat, along with the 10 million cars. This is shown as point B in the figure. Canadashould accept the deal because it gets the same number of cars and 50 million morebushes of wheat.Figure 46. Though the professor could do both writing and data collection faster than the student (that is,he has an absolute advantage in both), his time is limited. If the professor's comparativeadvantage is in writing, it makes sense for him to pay a student to collect the data, since that is the student's comparative advantage.7. a. English workers have an absolute advantage over Scottish workers in producing scones,since English workers produce more scones per hour (50 vs. 40). Scottish workers havean absolute advantage over English workers in producing sweaters, since Scottishworkers produce more sweaters per hour (2 vs. 1). Comparative advantage runs thesame way. English workers, who have an opportunity cost of 1/50 sweater per scone (1sweater per hour divided by 50 scones per hour), have a comparative advantage inscone production over Scottish workers, who have an opportunity cost of 1/20 sweaterper scone (2 sweaters per hour divided by 40 scones per hour). Scottish workers, whohave an opportunity cost of 20 scones per sweater (40 scones per hour divided by 2sweaters per hour), have a comparative advantage in sweater production over Englishworkers, who have an opportunity cost of 50 scones per sweater (50 scones per hourdivided by 1 sweater per hour).b. If England and Scotland decide to trade, Scotland will produce sweaters and trade themfor scones produced in England. A trade with a price between 20 and 50 scones persweater will benefit both countries, as they'll be getting the traded good at a lower pricethan their opportunity cost of producing the good in their own country.c. Even if a Scottish worker produced just one sweater per hour, the countries would stillgain from trade, because Scotland would still have a comparative advantage in producingsweaters. Its opportunity cost for sweaters would be higher than before (40 scones persweater, instead of 20 scones per sweater before). But there are still gains from tradesince England has a higher opportunity cost (50 scones per sweater).8. a. With no trade, one pair of white socks trades for one pair of red socks in Boston, sinceproductivity is the same for the two types of socks. The price in Chicago is 2 pairs of redsocks per pair of white socks.b. Boston has an absolute advantage in the production of both types of socks, since aworker in Boston produces more (3 pairs of socks per hour) than a worker in Chicago (2pairs of red socks per hour or 1 pair of white socks per hour).Chicago has a comparative advantage in producing red socks, since the opportunity costof producing a pair of red socks in Chicago is 1/2 pair of white socks, while theopportunity cost of producing a pair of red socks in Boston is 1 pair of white socks.Boston has a comparative advantage in producing white socks, since the opportunity costof producing a pair of white socks in Boston is 1 pair of red socks, while the opportunitycost of producing a pair of white socks in Chicago is 2 pairs of red socks.c. If they trade socks, Boston will produce white socks for export, since it has thecomparative advantage in white socks, while Chicago produces red socks for export,which is Chicago's comparative advantage.d. Trade can occur at any price between 1 and 2 pairs of red socks per pair of white socks.At a price lower than 1 pair of red socks per pair of white socks, Boston will choose toproduce its own red socks (at a cost of 1 pair of red socks per pair of white socks)instead of buying them from Chicago. At a price higher than 2 pairs of red socks per pairof white socks, Chicago will choose to produce its own white socks (at a cost of 2 pairs ofred socks per pair of white socks) instead of buying them from Boston.9. a. The cost of all goods is lower in Germany than in France in the sense that all goods canbe produced with fewer worker hours.b. The cost of any good for which France has a comparative advantage is lower in Francethan in Germany. Though Germany produces all goods with less labor, that labor maybe more valuable in the production of some goods and services. So the cost ofproduction, in terms of opportunity cost, will be lower in France for some goods.c. Trade between Germany and France will benefit both countries. For each good in whichit has a comparative advantage, each country should produce more goods than itconsumes, trading the rest to the other country. Total consumption will be higher inboth countries as a result.10. a. True; two countries can achieve gains from trade even if one of the countries has anabsolute advantage in the production of all goods. All that's necessary is that eachcountry have a comparative advantage in some good.b. False; it is not true that some people have a comparative advantage in everything theydo. In fact, no one can have a comparative advantage in everything. Comparativeadvantage reflects the opportunity cost of one good or activity in terms of another. If you have a comparative advantage in one thing, you must have a comparativedisadvantage in the other thing.c. False; it is not true that if a trade is good for one person, it can't be good for the otherone. Trades can and do benefit both sides especially trades based on comparativeadvantage. If both sides didn't benefit, trades would never occur.。