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✍ 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 describes 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.。
目 录第一部分 笔记和课后习题（含考研真题）详解[视频讲解]第1篇 导 言第1章 经济学十大原理1.1 复习笔记1.2 课后习题详解1.3 考研真题详解[视频讲解]第2章 像经济学家一样思考2.1 复习笔记2.2 课后习题详解2.3 考研真题详解第3章 相互依存性与贸易的好处3.1 复习笔记3.2 课后习题详解3.3 考研真题详解第2篇 市场如何运行第4章 供给与需求的市场力量4.1 复习笔记4.2 课后习题详解4.3 考研真题详解第5章 弹性及其应用5.1 复习笔记5.2 课后习题详解5.3 考研真题详解[视频讲解]第6章 供给、需求与政府政策6.1 复习笔记6.2 课后习题详解6.3 考研真题详解[视频讲解]第3篇 市场和福利第7章 消费者、生产者与市场效率7.1 复习笔记7.2 课后习题详解7.3 考研真题详解第8章 应用：赋税的代价8.1 复习笔记8.2 课后习题详解8.3 考研真题详解第9章 应用：国际贸易9.1 复习笔记9.2 课后习题详解9.3 考研真题详解第4篇 公共部门经济学第10章 外部性10.1 复习笔记10.2 课后习题详解10.3 考研真题详解[视频讲解]第11章 公共物品和公共资源11.1 复习笔记11.2 课后习题详解11.3 考研真题详解[视频讲解]第12章 税制的设计12.1 复习笔记12.2 课后习题详解12.3 考研真题详解第5篇 企业行为与产业组织第13章 生产成本13.1 复习笔记13.2 课后习题详解13.3 考研真题详解[视频讲解]第14章 竞争市场上的企业14.1 复习笔记14.2 课后习题详解14.3 考研真题详解[视频讲解]第15章 垄 断15.1 复习笔记15.2 课后习题详解15.3 考研真题详解[视频讲解]第16章 垄断竞争16.1 复习笔记16.2 课后习题详解16.3 考研真题详解[视频讲解]第17章 寡 头17.1 复习笔记17.2 课后习题详解17.3 考研真题详解[视频讲解]第6篇 劳动市场经济学第18章 生产要素市场18.1 复习笔记18.2 课后习题详解18.3 考研真题详解[视频讲解]第19章 收入与歧视19.1 复习笔记19.2 课后习题详解19.3 考研真题详解第20章 收入不平等与贫困20.1 复习笔记20.2 课后习题详解20.3 考研真题详解[视频讲解]第7篇 深入研究的论题第21章 消费者选择理论21.1 复习笔记21.2 课后习题详解21.3 考研真题详解[视频讲解]第22章 微观经济学前沿22.1 复习笔记22.2 课后习题详解22.3 考研真题详解[视频讲解]第二部分 模拟试题及详解曼昆《经济学原理（微观经济学分册）》（第6版）模拟试题及详解（一）曼昆《经济学原理（微观经济学分册）》（第6版）模拟试题及详解（二）第一部分 笔记和课后习题（含考研真题）详解[视频讲解]第1篇 导 言第1章 经济学十大原理1.1 复习笔记1．经济学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。
目 录第一部分 笔记和课后习题（含考研真题）详解[视频讲解]第1篇 导 言第1章 经济学十大原理1.1 复习笔记1.2 课后习题详解1.3 考研真题详解[视频讲解]第2章 像经济学家一样思考2.1 复习笔记2.2 课后习题详解2.3 考研真题详解第3章 相互依存性与贸易的好处3.1 复习笔记3.2 课后习题详解3.3 考研真题详解第2篇 市场如何运行第4章 供给与需求的市场力量4.1 复习笔记4.2 课后习题详解4.3 考研真题详解第5章 弹性及其应用5.1 复习笔记5.2 课后习题详解5.3 考研真题详解[视频讲解]第6章 供给、需求与政府政策6.1 复习笔记6.2 课后习题详解6.3 考研真题详解[视频讲解]第3篇 市场和福利第7章 消费者、生产者与市场效率7.1 复习笔记7.2 课后习题详解7.3 考研真题详解第8章 应用：赋税的代价8.1 复习笔记8.2 课后习题详解8.3 考研真题详解第9章 应用：国际贸易9.1 复习笔记9.2 课后习题详解9.3 考研真题详解第4篇 公共部门经济学第10章 外部性10.1 复习笔记10.2 课后习题详解10.3 考研真题详解[视频讲解]第11章 公共物品和公共资源11.1 复习笔记11.2 课后习题详解11.3 考研真题详解[视频讲解]第12章 税制的设计12.1 复习笔记12.2 课后习题详解12.3 考研真题详解第5篇 企业行为与产业组织第13章 生产成本13.1 复习笔记13.2 课后习题详解13.3 考研真题详解[视频讲解]第14章 竞争市场上的企业14.1 复习笔记14.2 课后习题详解14.3 考研真题详解[视频讲解]第15章 垄 断15.1 复习笔记15.2 课后习题详解15.3 考研真题详解[视频讲解]第16章 垄断竞争16.1 复习笔记16.2 课后习题详解16.3 考研真题详解[视频讲解]第17章 寡 头17.1 复习笔记17.2 课后习题详解17.3 考研真题详解[视频讲解]第6篇 劳动市场经济学第18章 生产要素市场18.1 复习笔记18.2 课后习题详解18.3 考研真题详解[视频讲解]第19章 收入与歧视19.1 复习笔记19.2 课后习题详解19.3 考研真题详解第20章 收入不平等与贫困20.1 复习笔记20.2 课后习题详解20.3 考研真题详解[视频讲解]第7篇 深入研究的论题第21章 消费者选择理论21.1 复习笔记21.2 课后习题详解21.3 考研真题详解[视频讲解]第22章 微观经济学前沿22.1 复习笔记22.2 课后习题详解22.3 考研真题详解[视频讲解]第二部分 模拟试题及详解曼昆《经济学原理（微观经济学分册）》（第6版）模拟试题及详解（一）曼昆《经济学原理（微观经济学分册）》（第6版）模拟试题及详解（二）第一部分 笔记和课后习题（含考研真题）详解[视频讲解]第1篇 导 言第1章 经济学十大原理1.1 复习笔记1．经济学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。
曼昆《经济学原理（微观经济学分册）》第 6 版课后习题详解第一篇导言第1章经济学十大原理一、看法题1.稀缺性稀缺性是指在给定的时间内，相对于人的需求而言，经济资源的供应老是不足的，也就是资源的有限性与人类的欲念无穷性之间的矛盾。
2.经济学经济学是研究如何将稀缺的资源有效地配置给互相竞争的用途，以令人类的欲念获取最大限度知足的科学。
此中微观经济学是以单个经济主体为研究对象，研究单个经济主风光对既定资源拘束时如何进行选择的科学；宏观经济学则以整个公民经济为研究对象，主要着眼于经济总量的研究。
3.效率效率是指人们在实践活动中的产出与投入比值或许是效益与成本比值，比值大效率高，比值小效率低。
它与产出或利润大小成正比，与投入或成本成反比。
4.同等同等是指人与人的利益关系及利益关系的原则、制度、做法、行为等都符合社会发展的需要，即经济成就在社会成员中公正分派的特征。
它是一个历史范围，按其所产生的社会历史条件和社会性质的不一样而不一样，不存在永久的公正；它也是一个客观范围，只管在不一样的社会形态中内涵不一样对其的理解不一样，但都是社会存在的反应，拥有客观性。
5.时机成本时机成本是指将一种资源用于某种用途，而未用于其余用途所放弃的最大预期利润。
其存在的前提条件是：①资源是稀缺的；②资源拥有多种用途；③资源的投向不受限制。
6.理性人理性人是指系统而有目的地尽最大努力去实现其目标的人，是经济研究中所假定的、在必定条件下拥有典型理性行为的经济活动主体。
7.边沿改动边沿改动是指对行动计划的细小增量调整。
8.激励激励是指惹起一个人做出某种行为的某种东西。
9.市场经济市场经济是指由家庭和公司在市场上的互相交易决定资源配置的经济，而资源配置本质上就是决定社会生产什么、生产多少、如何生产以及为谁生产的过程。
10.产权产权是指个人拥有并控制稀缺资源的能力，也能够理解为人们对其所交易东西的所有权，即人们在交易活动中使自己或别人在经济利益上得益或受损的权利。
二十三章1下列每种交易会影响CDP的哪一部分(如果有影响的话)并解释之。
A．家庭购买了一台新冰箱。
答：家庭购买了一台新冰箱会增加GDP中的消费(C)部分，因为家庭用于家用电器的支出计算在消费的耐用品类中。
B．杰妮姑妈买了一所新房子。
答：杰妮姑妈买了一所新房子会增加GDP中的投资(1)部分，因为家庭住宅能长期供人居住，提供服务。
它比一般耐用消费品的使用寿命更长，因此把住宅房屋的投资计算在投资中。
C.福特汽车公司由其存货中出售了一部雷鸟牌汽车。
答：福利汽车公司由其存货中出售了一部雷鸟牌汽车会减少现期GDP中的投资，因为销售中间物品存货时，企业的存货投资是负的，因而减少了当期的GDP。
C．你买了一个比萨饼。
答：我买了一个比萨饼会增加GDP中的消费(C)，因为我用于购买食品的支出计算在消费的非耐用品类中。
D．加利福尼亚重新铺设了101号高速公路。
答：加利福尼亚重新铺设了101号高速公路增加了GDP中的政府购买(G)，因为修建高速公路是政府的行为。
E．你的父母购买了一瓶法国红酒。
答：我的父母购买了一瓶法国红酒会减少GDP中的净出口(NX)，因为法国红酒是进口食品，它的购买增加了美国的进口。
F．本田公司扩大其在俄亥俄州马利斯维尔的工厂。
答：本田公司扩大其在俄亥俄州马利斯维尔的工厂增加了GDP中的净出口(NX)，因为本田公司是一家日本企业，它在美国的投资减少了美国对日本本田汽车的进口，使NX增加2．GDP组成部分中的“政府购买”并不包括用于社会保障这类转移支付的支出。
想想GDP 的定义，解释为什么转移支付不包括在政府购买内答：因为转移支付并不是要交换现在生产的物品或劳务，从宏观经济的角度看，转移支付就像税收和回扣一样。
转移支付和税收一样改变了家庭收入，但并没有反映经济的生产。
由于GDP是要衡量在某一既定时期一个国家从物品与劳务的生产中得到的收入，所以，不把转移支付包括在政府购买内。
6．考虑以下美国GDP的数据：A．1996年到1997年间名义收入增长率是多少(注意：增长率是一个时期到下一个时期百分比的变动。
第三篇市场和福利第七章消费者、生产者与市场效率问题与应用1．Melissa用120美元购买了一个iPod，并得到了80美元的消费者剩余。
A．她的支付意愿是多少？答：消费者剩余等于支付意愿减去付出的价格。
因此，梅莉莎须支付200 美元($120 + $80)。
B．如果她在降价销售时买了售价为90美元的iPod，她的消费者剩余会是多少？答：此时，她的消费者剩余为：200-90 =110 美元。
C．如果iPod的价格是250美元，她的消费者剩余会是多少？答：如果iPod 的价格是250 美元，其价格大于梅莉莎的支付愿意，因此她不会再买，这时的消费者剩余就为零。
2．加利福尼亚早来的寒流使柠檬变酸。
柠檬市场上消费者剩余会有什么变动？柠檬水市场上消费者剩余会有什么变动？用图形说明你的答案。
答：柠檬变酸，消费者对柠檬的评价下降，需求曲线向左下方移动。
在其他条件不变的情况下，消费者剩余减少。
如图7－2(a)所示，柠檬质量下降，使需求曲线从D1下降到D 2，△APE是原先的消费者剩余，△A′P′E′是变动后的消费者剩余，△APE>△A′P′E′。
由于柠檬价格的下降，柠檬水的投入成本减少，柠檬水的价格也下降。
在其他条件不变的情况下，柠檬水市场上消费者剩余增加，如图7－2(b)所示。
图7－2 寒流的影响3．假设对法国面包的需求增加。
在法国面包市场上，生产者剩余会发生什么变动？在面粉市场上，生产者剩余会发生什么变动？用图形说明你的答案。
答：由于需求增加，在其他条件不变的情况下，法国面包的价格会上升，市场上的生产者剩余增加。
如图7 －3(a)，价格从P1 上升到P2 ，销量从Q 1上升到Q 2，生产者剩余从面积P1BE1增加到面积P2BE2 。
由于面包产量上升，它的生产要素面粉的需求量也会上升。
在其他条件不变的情况下，面粉价格上升，市场上的生产者剩余增加。
如图7－3(b)所示，生产者剩余从面积P1BE1增加到面积P2BE2 。
Problems and Applications1.If an early freeze in California sours the lemon crop, the supply curve for lemons shiftsto the left, as shown in Figure 7-5.The result is a rise in the price of lemons and adecline in consumer surplus from A + B + C to just A. So consumer surplus declines by the amount B + C.Figure 7-5In the market for lemonade, the higher cost of lemons reduces the supply of lemonade,as shown in Figure 7-6.The result is a rise in the price of lemonade and a decline inconsumer surplus from D + E + F to just D, a loss of E + F. Note that an event that affectsconsumer surplus in one market often has effects on consumer surplus in other markets.Figure 7-62. A rise in the demand for French bread leads to an increase in producer surplus in themarket for French bread, as shown in Figure 7-7.The shift of the demand curve leads to an increased price, which increases producer surplus from area A to area A + B + C.Figure 7-7The increased quantity of French bread being sold increases the demand for flour, asshown in Figure 7-8.As a result, the price of flour rises, increasing producer surplusfrom area D to D + E + F. Note that an event that affects producer surplus in onemarket leads to effects on producer surplus in related markets.Figure 7-83. a.Bert’ s demand schedule is:Price Quantity DemandedMore than $7 0$5 to $7 1$3 to $5 2$1 to $3 3$1 or less 4Bert’ s demand curve is shown in Figure 7 -9.Figure 7-9b.When the price of a bottle of water is $4, Bert buys two bottles of water.Hisconsumer surplus is shown as area A in the figure.He values his first bottle ofwater at $7, but pays only $4 for it, so has consumer surplus of $3.He valueshis second bottle of water at $5, but pays only $4 for it, so has consumersurplus of $1.Thus Bert’ s total consumer surplus is $3 + $1 = $4, which isthe area of A in the figure.c.When the price of a bottle of water falls from $4 to $2, Bert buys three bottlesof water, an increase of one. His consumer surplus consists of both areas Aand B in the figure, an increase in the amount of area B. He gets consumersurplus of $5 from the first bottle ($7 value minus $2 price), $3 from thesecond bottle ($5 value minus $2 price), and $1 from the third bottle ($3 valueminus $2 price), for a total consumer surplus of $9. Thus consumer surplusrises by $5 (which is the size of area B) when the price of a bottle of water fallsfrom $4 to $2.4. a. Ernie ’ s supply schedule for water is:Price Quantity SuppliedMore than $7 4$5 to $7 3$3 to $5 2$1 to $3 1Less than $1 0Ernie’ s supply curve is shown in Figure 7 -10.Figure 7-10b.When the price of a bottle of water is $4, Ernie sells two bottles of water.Hisproducer surplus is shown as area A in the figure.He receives $4 for his firstbottle of water, but it costs only $1 to produce, so Ernie has producer surplusof $3.He also receives $4 for his second bottle of water, which costs $3 toproduce, so he has producer surplus of$1. Thus Ernie’ s total producersurplus 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 bottlesof water, an increase of one.His producer surplus consists of both areas Aand B in the figure, an increase by the amount of area B.He gets producersurplus of $5 from the first bottle ($6 price minus $1 cost), $3 from the secondbottle ($6 price minus $3 cost), and $1 from the third bottle ($6 price minus $5price), 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 $4to $6.5. a. From Ernie ’ s supply schedule and Bert ’ s demand schedule, the quantitydemanded and supplied are:Price Quantity Supplied Quantity Demanded$ 2 1 34 2 26 3 1Only a price of $4 brings supply and demand into equilibrium, withan equilibrium quantity of 2.b.At a price of $4, consumer surplus is $4 and producer surplus is $4, as shownin problems 3 and 4.Total surplus is $4 + $4 = $8.c.If Ernie produced one fewer bottle, his producer surplus would decline to $3,as shown in problem 4.If Bert consumed one fewer bottle, his consumersurplus would decline to $3, as shown in problem 3. So total surplus would declineto $3 + $3 = $6.d.If Ernie produced one additional bottle of water, his cost would be $5, but theprice is only $4, so his producer surplus would decline by $1.If Bertconsumed one additional bottle of water, his value would be $3, but the priceis $4, so his consumer surplus would decline by $1.So total surplus declinesby $1 + $1 = $2.6. a.The effect of falling production costs in the market for stereos results in a shiftto the right in the supply curve, as shown in Figure 7-11.As a result, theequilibrium price of stereos declines and the equilibrium quantity increases.b.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 belowthe price).After the shift in supply, producer surplus is areas E + F + G.Soproducer surplus changes by the amount F + G - B, which may be positive ornegative.The increase in quantity increases producer surplus, while thedecline in the price reduces producer surplus.Since consumer surplus risesby 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 curvebenefits consumers most.To take the most dramatic case, suppose thesupply curve were horizontal, as shown in Figure 7-12.Then there is noproducer surplus at all.Consumers capture all the benefits of fallingproduction costs, with consumer surplus rising from area A to area A + B.Figure 7-11Figure 7-127. Figure 7-13 shows supply and demand curves for haircuts. Supply equals demand ata quantity of three haircuts and a price between $4 and $5. Firms A, C, and D shouldcut the hair of Sally Jessy, Jerry, and Montel. 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 isthe 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 valueminus $4 cost for the third).Figure 7-138. a.The effect of falling production costs in the market for computers results in ashift to the right in the supply curve, as shown in Figure 7-14.As a result, theequilibrium price of computers declines and the equilibrium quantity increases.The decline in the price of computers increases consumer surplus from area Ato A + B + C + D, an increase in the amount B + C + D.Figure 7-14Prior to the shift in supply, producer surplus was areas B + E (the area abovethe supply curve and below the price).After the shift in supply, producersurplus 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 increasesproducer surplus, while the decline in the price reduces producer surplus. Sinceconsumer surplus rises by B + C + D and producer surplus rises by F + G - B,total surplus rises by C + D + F + G.——Figure 7-15b.Since adding machines are substitutes for computers, the decline in the priceof computers means that people substitute computers for adding machines,shifting the demand for adding machines to the left, as shown in Figure 7-15.The result is a decline in both the equilibrium price and equilibrium quantity ofadding machines.Consumer surplus in the adding-machine market changesfrom area A + B to A + C, a net gain of C - B.Producer surplus changes fromarea C + D + E to area E, a net loss of C + D.Adding machine producers aresad about technological advance in computers because their producersurplus declines.c.Since software and computers are complements, the decline in the price andincrease in the quantity of computers means that people’ s demand forsoftware increases, shifting the demand for software to the right, as shown inFigure 7-16. 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 increase of A - C. Producer surplus changes from E to C + D + E, anincrease of C + D, so software producers should be happy about the technologicalprogress in computers.d.Yes, this analysis helps explain why Bill Gates is one the world’ s richest msince his company produces a lot of software that’ s a complement withcomputers and there has been tremendous technological advance incomputers.——Figure 7-169. a. Figure 7-17 illustrates the demand for medical care. If each procedure has aprice of $100, quantity demanded will be Q 1 procedures.Figure 7-17b.If consumers pay only $20 per procedure, the quantity demanded will be Q 2procedures.Since the cost to society is $100, the number of proceduresperformed is too large to maximize total surplus.The quantity thatmaximizes total surplus is Q 1 procedures, which is less than Q2.c.The use of medical care is excessive in the sense that consumers getprocedures 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 ofthe procedure.But this would require eliminating insurance.Anotherpossibility would be that the insurance company, which pays most of themarginal cost of the procedure ($80, in this case) could decide whether theprocedure should be performed.But the insurance company doesn’ t get thebenefits of the procedure, so its decisions may not reflect the value to theconsumer.10. a. Figure 7-18 illustrates the effect of the drought. The supply curve shifts tothe left, leading to a rise in the equilibrium price from P 1 to P 2 and a decline inthe equilibrium quantity from Q 1 to Q 2 .Figure 7-18b.If the price of water is not allowed to change, there will be an excess demandfor water, with the shortage shown on the figure as the difference between Q 1and Q 3 .c.The system for allocating water is inefficient because it no longer allocateswater to those who value it most highly.Some people who value water atmore than its cost of production will be unable to obtain it, so societysurplus isn’ t maximized.The allocation system seems unfair as well.Water is allocated simply on pastusage, rewarding past wastefulness.If a family’ s demand for water increases,——say because of an increase in family size, the policy doesn ’ t allow them to obtain more water. Poor families, who probably used water mostly fornecessary uses like drinking, would suffer more than wealthier families whowould have to cut back only on luxury uses of water like operating backyardfountains and pools. However, the policy also keeps the price of water lower,which benefits poor families, since otherwise more of their family budgetwould have to go for water.d. If the city allowed the price of water to rise to its equilibrium price P 2 , theallocation would be more efficient. Quantity supplied would equal quantitydemanded and there would be no shortage. Total surplus would bemaximized.Whether the market allocation would be more or less fair than theproportionate reduction in water under the old policy is difficult to say, but it islikely to be more fair. Notice that the quantity supplied would be higher (Q 2)in this case than under the water restrictions (Q 3 ), so there ’ s less reduction inwater usage. To make the market solution even more fair, the governmentcould provide increased tax relief or welfare payments for poor families whosuffer from paying the higher water prices.。
rketsWHAT’S NEW IN THE SIXTH EDITION:There are no major changes to this chapter.LEARNING OBJECTIVES:By the end of this chapter, students should understand:the link between buyers’ willingness to pay for a good and the demand curve.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 then7CONSUMERS, PRODUCERS, AND THEEFFICIENCY OF MARKETSutilized 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 affectseconomic well-being.Students often are confused by the use of the word “welfare.” Remind themthat we are talking about social well-being and not public assistance.II. Consumer SurplusA. Willingness to Pay1. Definition of willingness to pay: the maximum amount that a buyer will pay for agood.2. Example: You are auctioning a mint-condition recording of Elvis Presley’s firstalbum. Four buyers show up. Their willingness to pay is as follows:If the bidding goes to slightly higher than $80, all buyers drop outexcept for John. Because John is willing to pay more than he has to forthe 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 goodminus 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 auctionJohn 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 therare Elvis Presley album.2. At any given quantity, the price given by the demand curve reflects thewillingness to pay of the marginal buyer. Because the demand curve shows the buyers’ willingness to pay, we can use the demand curve to measure consumer surplus.Figure 23. Consumer surplus can be measured as the area below the demand curve and above theprice.C. How a Lower Price Raises Consumer SurplusFigure 31. As price falls, consumer surplus increases for two reasons.a. Those already buying the product will receive additional consumer surplusbecause 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 andreceive consumer surplus on these additional units of output purchased (area Bon the graph).D. What Does Consumer Surplus MeasureIt is important to stress that consumer surplus is measured in monetaryterms. Consumer surplus gives us a way to place a monetary cost on1. Remember that consumer surplus is the difference between the amount that buyersare 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 buyersthemselves perceive it.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.III. Producer SurplusA. Cost and the Willingness to Sell1. Definition of cost: the value of everything a seller must give up to produce agood.You will need to take some time to explain the relationship between theproducers’ willingness to sell and the cost of producing the good. Therelationship between cost and the supply curve is not as apparent as the2. Example: You want to hire someone to paint your house. You accept bids for thework 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:3. Bidding will stop when the price gets to be slightly below $600. All sellers willdrop 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 theseller’s cost of providing it.5. Note that if you had more than one house to paint, the price in the auction wouldend 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 curvefor house painting services.Price Sellers Quantity Supplied$900 or more Mary, Frida, Georgia, Grandma4$800 to $900Frida, Georgia, Grandma3$600 to $800Georgia, Grandma2$500 to $600Grandma1less than $500None02. At any given quantity, the price given by the supply curve represents the cost ofthe marginal seller. Because the supply curve shows the sellers’ cost (willingness to sell), we can use the supply curve to measure producer surplus.3. Producer surplus can be measured as the area above the supply curve and below theprice.Figure 4Figure 5C. How a Higher Price Raises Producer Surplus1. As price rises, producer surplus increases for two reasons.a. Those already selling the product will receive additional producer surplusbecause they are receiving more for the product than before (area C on thegraph).b. Because the price is now higher, some new sellers will enter the market andreceive producer surplus on these additional units of output sold (area D onthe graph).D. Producer surplus is used to measure the economic well-being of producers, much like Figure 6ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price floors from Chapter 6. Redraw the market for an agricultural product such as corn. Draw in a price support above the equilibriumprice.Then go through: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 by Sellers:2. Definition of efficiency: the property of a resource allocation of maximizing thetotal surplus received by all members of society .3. Definition of equality: the property of distributing economic prosperity uniformlythe members of society .B. Evaluating the Market EquilibriumTotal Surplus = Value to Buyers Cost to SellersFigure 7Now might be a good time to point out that many government policies involvea trade-off between efficiency and equity. When you evaluate government Pretty Woman, Chapter 6. Vivien (Julia Roberts) and Edward (Richard Gere)negotiate a price. Afterward, Vivien reveals she would have accepted a lower price, while Edward admits he would have paid more. If you have done a good job of introducing consumer and producer surplus, you will see the1. At the market equilibrium price:a. Buyers who value the product more than the equilibrium price will purchase theproduct; those who do not, will not purchase the product. In other words, thefree market allocates the supply of a good to the buyers who value it mosthighly, as measured by their willingness to pay.b. Sellers whose costs are lower than the equilibrium price will produce theproduct; those whose costs are higher, will not produce the product. In otherwords, the free market allocates the demand for goods to the sellers who canproduce it at the lowest cost.2. Total surplus is maximized at the market equilibrium.Figure 8a. At any quantity of output smaller than the equilibrium quantity, the value ofthe product to the marginal buyer is greater than the cost to the marginalseller so total surplus would rise if output increases.b. At any quantity of output greater than the equilibrium quantity, the value ofthe product to the marginal buyer is less than the cost to the marginal sellerso total surplus would rise if output decreases.3. Note that this is one of the reasons that economists believe Principle #6: Marketsare usually a good way to organize economic activity.It would be a good idea to remind students that there are circumstanceswhen the market process does not lead to the most efficient outcome.Examples include situations such as when a firm (or buyer) has market powerC. 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 describes economist Chip Case’s experiencewith ticket scalping.D. Case Study: Should There Be a Market in Organs1. 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 ofresources, 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 marketsworked.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 P1and theconsumer surplus that results from that price is denoted CS. Consumer surplus isthe amount a buyer is willing to pay for a good minus the amount the buyeractually pays for it. It measures the benefit to buyers of participating in amarket.Figure 1 Figure 22. Figure 2 shows the supply curve for turkey. The price of turkey is P1and theproducer surplus that results from that price is denoted PS. Producer surplus isthe 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 ofparticipating 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 thanthe equilibrium quantity would lower total surplus because the value to themarginal buyer would be lower than the cost to the marginal seller on thoseadditional units.Questions for Review1. The price a buyer is willing to pay, consumer surplus, and the demand curve areall closely related. The height of the demand curve represents the willingness topay of the buyers. Consumer surplus is the area below the demand curve and abovethe price, which equals the price that each buyer is willing to pay minus theprice 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. Producersurplus is the area below the price and above the supply curve, which equals theprice 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 ofconsumer surplus and producer surplus. But efficiency may not be the only goal ofeconomic policymakers; they may also be concerned about equity the fairness ofthe distribution of well-being.5. The invisible hand of the marketplace guides the self-interest of buyers andsellers into promoting general economic well-being. Despite decentralized decisionmaking and self-interested decision makers, free markets often lead to anefficient outcome.6. Two types of market failure are market power and externalities. Market power maycause market outcomes to be inefficient because firms may cause price and quantityto differ from the levels they would be under perfect competition, which keepstotal surplus from being maximized. Externalities are side effects that are nottaken into account by buyers and sellers. As a result, the free market does notmaximize 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 becausethe price is greater than her willingness to pay. Therefore, she would receiveno consumer surplus.2. If an early freeze in California sours the lemon crop, the supply curve for lemonsshifts to the left, as shown in Figure 5. The result is a rise in the price oflemons and a decline in consumer surplus from A + B + C to just A. So consumersurplus declines by the amount B + C.Figure 5 Figure 6In the market for lemonade, the higher cost of lemons reduces the supply oflemonade, as shown in Figure 6. The result is a rise in the price of lemonade anda decline in consumer surplus from D + E + F to just D, a loss of E + F. Note thatan event that affects consumer surplus in one market often has effects on consumersurplus in other markets.3. A rise in the demand for French bread leads to an increase in producer surplus inthe market for French bread, as shown in Figure 7. The shift of the demand curveleads to an increased price, which increases producer surplus from area A to areaA +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 producersurplus from area D to D + E + F. Note that an event that affects producer surplusin one market leads to effects on producer surplus in related markets.Figure 84. a. Bert’s demand schedule is:Price Quantity DemandedMore than $70$5 to $71$3 to $52$1 to $33$1 or less4Bert’s demand curve is shown in Figure 9.Figure 9b. When the price of a bottle of water is $4, Bert buys two bottles of water. Hisconsumer surplus is shown as area A in the figure. He values his first bottleof water at $7, but pays only $4 for it, so has consumer surplus of $3. Hevalues his second bottle of water at $5, but pays only $4 for it, so hasconsumer 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 threebottles of water, an increase of one. His consumer surplus consists of bothareas A and B in the figure, an increase in the amount of area B. He getsconsumer surplus of $5 from the first bottle ($7 value minus $2 price), $3 fromthe second bottle ($5 value minus $2 price), and $1 from the third bottle ($3value minus $2 price), for a total consumer surplus of $9. Thus consumersurplus rises by $5 (which is the size of area B) when the price of a bottle ofwater falls from $4 to $2.5. a. Ernie’s supply schedule for water is:Price Quantity SuppliedMore than $74$5 to $73$3 to $52$1 to $31Less than $10Ernie’s su pply curve is shown in Figure 10.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 threebottles of water, an increase of one. His producer surplus consists of bothareas 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 quantitydemanded and supplied are:Only a price of $4 brings supply and demand into equilibrium, with an equilibrium quantity of two.b. At a price of $4, consumer surplus is $4 and producer surplus is $4, as shownin 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, asshown 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 theprice 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 ashift to the right in the supply curve, as shown in Figure 11. As a result, theequilibrium 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 theprice). After the shift in supply, producer surplus is areas E + F + G. Soproducer surplus changes by the amount F + G –B, which may be positive ornegative. The increase in quantity increases producer surplus, while thedecline in the price reduces producer surplus. Because consumer surplus risesby 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 curvebenefits consumers most. To take the most dramatic case, suppose the supplycurve were horizontal, as shown in Figure 12. Then there is no producer surplusat all. Consumers capture all the benefits of falling production costs, withconsumer surplus rising from area A to area A + B.Figure 128. Figure 13 shows supply and demand curves for haircuts. Supply equals demand at aquantity of three haircuts and a price between $4 and $5. Firms A, C, and D shouldcut the hair of Ellen, Jerry, and Phil. Oprah’s willingness to pay is too low andfirm B’s costs are too high, so they do not participate. The maximum totalsurplus is the area between the demand and supply curves, which totals $11 ($8value minus $2 cost for the first haircut, plus $7 value minus $3 cost for thesecond, 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 ashift to the right in the supply curve, as shown in Figure 14. As a result, theequilibrium price of computers declines and the equilibrium quantity increases.The decline in the price of computers increases consumer surplus from area A toA +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 abovethe supply curve and below the price). After the shift in supply, producersurplus 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.b. Because typewriters are substitutes for computers, the decline in the price ofcomputers 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 andincrease in the quantity of computers means that the demand for softwareincreases, 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. Consumersurplus 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, sosoftware producers should be happy about the technological progress incomputers.Figure 16d. Yes, this analysis helps explain why Bill Gates is one the world’s richestpeople, because his company produces a lot of software that is a complementwith 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 costof an extra 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,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 aprice of $100, quantity demanded will be Q1 procedures.Figure 18b. If consumers pay only $20 per procedure, the quantity demanded will be Q2procedures. Because the cost to society is $100, the number of proceduresperformed is too large to maximize total surplus. The quantity that maximizestotal surplus is Q1 procedures, which is less than Q2.c. The use of medical care is excessive in the sense that consumers get procedureswhose value is less than the cost of producing them. As a result, theeconomy’s total surplus is reduced.d. To prevent this excessive use, the consumer must bear the marginal cost of theprocedure. But this would require eliminating insurance. Another possibilitywould be that the insurance company, which pays most of the marginal cost ofthe procedure ($80, in this case) could decide whether the procedure should beperformed. But the insurance company does not get the benefits of the procedure,so its decisions may not reflect the value to the consumer.。
第7章 消费者、生产者与市场效率7.1 复习笔记1．消费者剩余（1）消费者剩余等于买者对一种物品的支付意愿减去其实际为此所支付的量。
每一个买者愿意支付的最高价格称为支付意愿（willingness to pay），它衡量买者对物品的评价。
每个买者都希望以低于自己支付意愿的价格购买商品，并拒绝以高于自己支付意愿的价格购买，而且，对于正好等于自己支付意愿的价格购买商品持无所谓的态度。
消费者愿意支付的价格与其实际所支付的价格之间的差额就是消费者剩余。
（2）用需求曲线衡量消费者剩余消费者剩余与一种物品的需求曲线密切相关，通过求出需求曲线以下和价格以上的面积，可以来计算消费者剩余。
（3）价格下降可以增加消费者剩余当一种物品的价格下降时，消费者剩余因两个原因而增加：①原有消费者可以为要购买的量少支付而得到了更多的剩余；②新的买者由于现在价格低于他们的支付意愿而进入市场，新的消费者剩余出现。
（4）消费者剩余衡量买者参与市场中得到的利益，反映了买者的经济福利由于需求曲线是用支付意愿衡量的买者对一种物品的评价，所以，消费者剩余衡量“作为买者自己感觉到的利益”。
因此，如果政策制定者尊重买者的偏好，消费者剩余就是对买者利益的一种恰当衡量。
经济学家普遍认为，除了吸毒等例外情况，买者都是理性的。
而且，买者的偏好应该受到尊重。
2．生产者剩余（1）生产者剩余等于卖者出售其物品得到的量减去它们的生产成本市场上每一个潜在卖者都有某种生产成本。
这种成本是生产者为了生产一种产品所必须放弃的一切东西的价值，并应该解释为生产者生产的机会成本——钱包里的实际支出加生产者时间的价值。
生产成本是卖者为了生产物品所愿意接受的最低值，生产者在提供一定数量的某种产品时实际接受的总支付和愿意接受的最小总支付之间的差额就是生产者剩余。
（2）用供给曲线衡量生产者剩余通过求出价格以下和供给曲线以上的面积，可以来计算生产者剩余。
（3）价格上升可以增加生产者剩余这种生产者剩余的增加由两部分构成：①原有卖者可以为要出卖的量而得到了更多的利益；②一些新卖者进入市场，新的生产者剩余出现。
曼昆《经济学原理（微观经济学分册）》第6版课后习题详解（1~2章）第一篇：曼昆《经济学原理(微观经济学分册)》第6版课后习题详解(1~2章)曼昆《经济学原理（微观经济学分册）》第6版课后习题详解第一篇导言第1章经济学十大原理一、概念题 1.稀缺性稀缺性是指在给定的时间内，相对于人的需求而言，经济资源的供给总是不足的，也就是资源的有限性与人类的欲望无限性之间的矛盾。
2.经济学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。
其中微观经济学是以单个经济主体为研究对象，研究单个经济主体面对既定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，主要着眼于经济总量的研究。
3.效率效率是指人们在实践活动中的产出与投入比值或者是效益与成本比值，比值大效率高，比值小效率低。
它与产出或收益大小成正比，与投入或成本成反比。
4.平等平等是指人与人的利益关系及利益关系的原则、制度、做法、行为等都合乎社会发展的需要，即经济成果在社会成员中公平分配的特性。
它是一个历史范畴，按其所产生的社会历史条件和社会性质的不同而不同，不存在永恒的公平；它也是一个客观范畴，尽管在不同的社会形态中内涵不同对其的理解不同，但都是社会存在的反映，具有客观性。
5.机会成本机会成本是指将一种资源用于某种用途，而未用于其他用途所放弃的最大预期收益。
其存在的前提条件是：①资源是稀缺的；②资源具有多种用途；③资源的投向不受限制。
6.理性人理性人是指系统而有目的地尽最大努力去实现其目标的人，是经济研究中所假设的、在一定条件下具有典型理性行为的经济活动主体。
7.边际变动边际变动是指对行动计划的微小增量调整。
8.激励激励是指引起一个人做出某种行为的某种东西。
9.市场经济市场经济是指由家庭和企业在市场上的相互交易决定资源配置的经济，而资源配置实际上就是决定社会生产什么、生产多少、如何生产以及为谁生产的过程。
第15章垄断15.1 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．垄断（1）垄断市场指整个行业中只有一个厂商的市场组织。
具体地说，垄断市场的条件主要有这样三点：第一，市场上只有一个厂商生产和销售商品；第二，该厂商生产和销售的商品没有任何相近的替代品；第三，其他任何厂商进入该行业都极为困难或不可能。
（2）产生垄断的原因垄断的基本原因是进入壁垒，即垄断者能在其市场上保持唯一卖者的地位，是因为其他企业不能进入市场并与之竞争。
进入壁垒又有三个主要来源：①垄断资源。
生产所需要的关键资源由一家企业拥有。
②政府管制。
政府给予一个企业排他性地生产某种产品或劳务的权利。
③自然垄断。
某个企业能以低于大量生产者的成本生产产品。
2．垄断者的生产和定价决策（1）需求曲线垄断厂商所面临的需求曲线就是市场的需求曲线，它是一条向右下方倾斜的曲线，即垄断厂商的销售量和市场价格成反方向变动。
这条向右下方倾斜的需求曲线表示垄断厂商可以通过改变销售量来控制市场价格，即以减少销售量来抬高价格或者以增加销售量来降低价格。
（2）垄断者的收益垄断厂商的边际收益（MR）曲线也是向右下方倾斜的，且位于平均收益（AR）曲线的下方，这表示在每一个销售量上厂商的边际收益都小于平均收益。
之所以出现MR AR<，是因为只要平均量下降，边际量就总是小于平均量。
垄断者的边际收益与竞争企业大不相同。
当垄断者增加它销售的数量时，这对总收益（P Q⨯）有两种效应：①产量效应：销售的产量越多，因此Q越大。
②价格效应：价格下降，因此P降低。
曼昆《经济学原理（微观经济学分册）》第6版课后习题详解（1~2章）曼昆《经济学原理（微观经济学分册）》第6版课后练习的详细讲解第一篇导言第一章经济学十大原理一、概念题1.稀缺性稀缺性是指在一定时间内，经济资源的供给相对于人的需求总是不足的，即资源的有限性与人的欲望的无限性之间的矛盾。
2.经济学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。
微观经济学是以单个经济主体为研究对象，研究单个经济主体在面临既定资源约束时如何做出选择的科学；宏观经济学以整个国民经济为研究对象，主要研究经济总量。
3.效率效率是指人们在实践活动中的产出与投入比值或者是效益与成本比值，比值大效率高，比值小效率低。
它与产出或收益大小成正比，与投入或成本成反比。
4.平等平等是指人与人之间的利益关系，利益关系的原则、制度、实践和行为符合社会发展的需要，即经济成果在社会成员之间公平分配的特征。
它是一个历史范畴，根据社会历史条件和社会性质而变化，没有永恒的公平；它也是一个客观范畴。
虽然它的内涵在不同的社会形态中有所不同，对它的理解也有所不同，但它是社会存在的反映，具有客观性。
5.机会成本机会成本是指将一种资源用于某种用途，而未用于其他用途所放弃的最大预期收益。
其存在的前提条件是：①资源是稀缺的；②资源具有多种用途；③资源的投向不受限制。
6.理性人理性人是指为实现自己的目标而做出系统而有目的的努力的人。
他是经济研究中假定的经济活动的主体，在一定条件下具有典型的理性行为。
7.边际变化边际变动是指对行动计划的微小增量调整。
8.激励动机是促使一个人做某事的东西。
9.市场经济市场经济是指由家庭和企业在市场上的相互交易决定资源配置的经济，而资源配置实际上就是决定社会生产什么、生产多少、如何生产以及为谁生产的过程。
10.产权产权是指个人拥有和控制稀缺资源的能力。
它也可以理解为人们对他们交易的物品的所有权，即人们在贸易活动中为经济利益而使自己或他人受益或受损的权力。
目 录第1篇 导 言第1章 经济学十大原理第2章 像经济学家一样思考第3章 相互依存性与贸易的好处第2篇 市场如何运行第4章 供给与需求的市场力量第5章 弹性及其应用第6章 供给、需求与政府政策第3篇 市场和福利第7章 消费者、生产者与市场效率第8章 应用：赋税的代价第9章 应用：国际贸易第4篇 公共部门经济学第10章 外部性第11章 公共物品和公共资源第12章 税制的设计第5篇 企业行为与产业组织第13章 生产成本第14章 竞争市场上的企业第15章 垄 断第16章 垄断竞争第17章 寡 头第6篇 劳动市场经济学第18章 生产要素市场第19章 收入与歧视第20章 收入不平等与贫困第7篇 深入研究的论题第21章 消费者选择理论第22章 微观经济学前沿第1篇 导 言第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。
第七章 复习思考题 参考答案1、为什么垄断厂商的需求曲线是向右下方倾斜的？并解释相应的TR 曲线、AR 曲线和MR 曲线的特征以及相互关系。
解答：垄断厂商所面临的需求曲线是向右下方倾斜的，其理由主要有两点：第一，垄断厂商所面临的需求曲线就是市场的需求曲线，而市场需求曲线一般是向右下方倾斜的，所以垄断厂商的需求量与价格成反方向的变化。
第二，假定厂商的销售量等于市场的需求量，那么，垄断厂商所面临的向右下方倾斜的需求曲线表示垄断厂商可以通过调整销售量来控制市场的价格，即垄断厂商可以通过减少商品的销售量来提高市场价格，也可以通过增加商品的销售量来降低市场价格。
关于垄断厂商的TR 曲线、AR 曲线和MR 曲线的特征以及相互关系，以图7-1加以说明： 第一，平均收益AR 曲线与垄断厂商的向右下方倾斜的d 需求曲线重叠。
因为，在任何的销售量上，都是P=AR 。
第二，边际收益MR 曲线是向右下方倾斜的，且位置低于AR 曲线。
其原因在于AR 曲线是一条下降的曲线。
此外，在线性需求曲线的条件下，AR 曲线和MR 曲线的纵截距相同，而且MR 曲线的斜率的绝对值是AR 曲线的斜率的绝对值的两倍。
第三，由于MR 值是TR 曲线的斜率，即dQdTR MR ，所以，当MR>0时，TR 曲线是上升的；当MR ＜0时，TR 曲线是下降的；当MR=0时，TR 曲线达极大值。
图 7-1 垄断竞争厂商的AR 与TR 之间的关系2、根据图7-22中线性需求曲线d 和相应的边际收益曲线MR ，试求：（1）A 点所对应的MR 值；（2）B 点所对应的MR 值。
解答：（1）根据需求的价格点弹性的几何意义，可得A 点的需求的价格弹性为： 25)515(=-=d e ， 或者，2)23(2=-=d e ，根据)11(d e P MR -=，则A 点的MR 值为：MR=2×（2×1/2）=1。
（2）方法同（1）。
B 点所对应的MR ＝－1。
第2篇市场如何运行第4章供给与需求的市场力量4.1 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．市场与竞争市场（market）是某种物品或劳务的一群买者与卖者组成的一个群体。
买者作为一个群体决定了一种物品或劳务的需求，而卖者作为一个群体决定了一种物品或劳务的供给。
（1）市场类型的划分与特征市场类型的划分与特征如表4-1所示：表4-1 市场类型的划分和特征（2）完全竞争市场完全竞争市场指竞争不存在任何阻碍和干扰因素的市场情况，亦即没有任何垄断因素的市场结构。
完全竞争市场有两个主要特征：①用于销售的物品是完全相同的。
②买者和卖者如此之多，以至于没有一个买者或卖者可以影响价格。
由于完全竞争市场上的买者与卖者必须接受市场决定的价格，所以，他们被称为价格接受者。
2．需求（1）定义一种商品的需求指消费者在一定时期内在各种可能的价格水平愿意而且能够购买的该商品的数量。
（2）需求定理在其他条件相同时，一种物品价格上升，该物品需求量减少；价格下降，需求量增加。
（3）需求的表示需求表：表示一种物品价格与需求量之间关系的表格。
需求曲线：表示一种物品与需求量之间关系的图形。
根据需求定理，需求曲线向右下方倾斜。
（4）市场需求与个人需求市场需求是所有个人对某种物品或劳务需求的总和，把个人需求曲线水平相加可以得出市场需求曲线。
市场需求曲线表示在所有其他影响消费者需求的因素保持不变时，一种物品的总需求量如何随该物品价格的变动而变动。
（5）影响需求曲线移动的因素当人们改变他们在每种价格上希望购买的量时，需求曲线移动。
曼昆《经济学原理（微观经济学分册）》（第6版）第3篇 市场和福利第7章 消费者、生产者与市场效率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．福利经济学（welfare economics ）答：福利经济学是一种规范经济学，研究的是整个经济的资源配置与个人福利的关系，特别是市场经济体系的资源配置与福利的关系，以及与此有关的各种政策问题。
福利经济学研究要素在不同厂商之间的最优分配以及产品在不同家庭之间的最优配置。
它的主要特点是：从一定的价值判断出发建立理论体系，在边际效用论的基础上建立福利概念，依据既定的社会目标和福利理论制定经济政策。
20世纪初，西方国家为调和日益尖锐的社会矛盾，福利经济学应运而生。
英国经济学家A ·C ·庇古是福利经济学的创始人和主要代表。
庇古1920年出版的《福利经济学》是福利经济学产生的标志。
庇古的福利经济学有两个基本命题：一是国民收入总量愈大，社会经济福利愈大；二是国民收入分配愈均等，社会经济福利愈大。
由于在1929～1933年的大危机以后，庇古的理论已经不能完全适应需要，因此他的理论被称为旧福利经济学。
与庇古的旧福利经济学相对的是其后出现的新福利经济学，代表人物有勒纳、卡尔多、希克斯等。
2．支付意愿（willingness to pay ）答：支付意愿指买者愿意为某种商品支付的最高价格。
支付意愿是衡量买者对物品的评价，评价越高支付意愿越强，愿意支付的价格越高，反之，评价越低支付意愿越弱，愿意支付的价格越低。
3．消费者剩余（consumer surplus ）（西北大学2004、2006研；华南理工大学2007、2008研；北京工业大学2008研）答：消费者剩余指消费者购买一定数量的某种产品时愿意支付的价格与其实际所支付的价格之间的差额。
