曼昆 经济学原理 第五章 弹性及其应用

曼昆《微观经济学》复习题库第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7章消费者、生产者与市场效率；第10章外部性；第11章公共物品与公有资源；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章寡头；第17章垄断竞争；第18 生产要素市场；第19-20收入与贫困；第21章消费者选择理论此次考试试题题型如下：一、名词解释（5个名词，每个3分，共15分）二、选择题（15题，每题2分，共30分）三、判断题（15题，每题1分，共15分）四、简答题（4题，每题5分，共20分）五、作图和计算题（2题，每题10分，共20分）作图和计算题以书后作业题为主，主要集中在供给与需求，弹性、生产成本或完全竞争企业这几章。

其它的就从下面的题库里选取。

第一篇导言一、名词解释1、经济学2、稀缺性3、机会成本4、理性人5、市场经济6、市场失灵7、外部性8、生产可能性边界 9、微观经济学 10、宏观经济学 11、实证表述 12、规范表述13、绝对优势 14、比较优势二、判断题1、当经济学家说“天下没有免费的午餐”时，他们是指所有经济决策都涉及到权衡取舍2、只有当一种行为的边际利益大于边际成本时，理性人才行动。

3、即使增加的汽车产量的成本大于所得到的价格，只要企业有利可图，汽车制造商就应该继续生产增加的汽车。

4、对一个学生来说，看一场篮球赛的机会成本应该包括门票的价格和可以用于用于学习的时间的价值。

5、当一架喷气式飞机从头上飞过时，噪音引起外部性6、李文更擅长打扫卫生，姜飞更擅长做饭。

如果姜飞专门做饭而李文专门打扫卫生，这将比他们平等地分摊家务所需要的时间少。

7、一个农民在小麦市场上更可能有市场势力。

8、美国工人有较高的生活水平是因为美国有较高的最低工资9、在短期中，降低通货膨胀往往会引起失业减少。

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》名词解释归纳——上下册一、经济学十大原理1、稀缺性：社会资源的有限性。

2、经济学：研究社会如何管理自己的稀缺资源。

3、效率：社会能从其稀缺资源中得到最多东西的特性。

4、平等：经济成果在社会成员中公平分配的特性。

5、机会成本：为了得到某种东西所必须放弃的东西。

理性人：系统而有目的地尽最大努力实现起目标的人。

6、边际变动：对行动计划微小的增量调整。

激励：引起一个人做出某种行为的某种东西。

7、市场经济：当许多企业和家庭在物品与劳务市场上相互交易时，通过他们的分散决策配置资源的经济。

8、市场失灵：市场本身不能有效配置资源的情况。

9、外部性：一个人的行为对旁观者福利的影响。

10、市场势力：一个经济活动者（或经济活动者的一个小集团）对市场价格有显著影响的能力。

11、生产率：一个工人一小时所生产的物品与劳务量。

12、通货膨胀：经济中物价总水平的上升。

13、菲利普斯曲线：通货膨胀与失业之间的短期权衡取舍。

14、经济周期：就业和生产等经济活动的波动（就是生产这类经济活动的波动。

）二、像经济学家一样思考15、循环流向图：一个说明货币如何通过市场在家庭与企业之间流动的直观经济模型。

16、生产可能性边界：表示一个经济在可得到的生产要素与生产技术既定时所能生产的产量的各种组合的图形。

17、微观经济学：研究家庭和企业如何做出决策，以及它们在市场上的相互交易。

18、宏观经济学：研究整体经济现象，包括通货膨胀、失业和经济增长。

19、实证表述：企图描述世界是什么的观点。

20、规范描述：企图描述世界应该如何运行的观点。

三、绝对依存性与贸易的好处21、绝对优势：根据生产率比较一种物品的生产者。

22、比较优势：根据机会成本比较一种物品的生产者。

23、进口：国外生产而在国内销售的物品。

24、出口：国内生产而在国外销售的物品。

四、供给与需求的市场力量25、市场：由某种物品或劳务的买者与卖者组成的一个群体。

26、竞争市场：有许多买者与卖者，以致于每个人对市场价格的影响都微乎其微的市场。

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。

《曼昆一微观经济学》重点总结第1篇导言懐1章经济学十夭原理尤济学家研究：人们如何作出决策；人们如何相互交易：影响整体经济的力量和趋势。

效率是指经济蛋糕的人小，而平等则是指如何分割这块蛋糕。

理性人通常通过比较边际利益9边际成本來做出决策。

当且仅当一种行为的边际利益〉边际成本时，一个理性决策者才会采取这种行动。

在经济学中，激励起着中心作用。

价格是“看不见的手”用来指引经济活动的工具。

产权包括所有权,使用权,处置权,收益权。

市场失灵的原因：垄睡：信息不对称:外部性:市场势力。

生产率取决于设备,劳动者的技能以及町用的技术。

・经济学十人原理人们如何做出决策1、人们面临权衡取舍2、某种东西的成本是为了得到它所放弃的东酋3、理性人考虑边际量4、人们会对激励做出反应5、贸易可以使每个人的状况都变得更好人们如何相互交易6、市场通常是组织经济活动的一种好办法7、政府有时可以改善市场结果8、一国的生活水平取决于它生产物品与劳务的能力整体经济如何运行9、当政府发行了过多货币时，物价上升10、社会面临通货膨胀与失业之间的短期权衡取舍第2章像经济学家一样思考•循环流向图：•个说明货币如何通过市场在家庭与企业Z间流动的直观经济模型。

P26生产可能性边界：表示在町得到的生产要素与生产技术既定时，一个经济所能生产的产品数量的各种组合的图形。

P28生产可能性边界表明在某一特定时期内生产不同物品Z间的权衡取舍，但随着时间的推移, 这种权衡収舍可以改变。

・人篡数经济学家一致同意的十个主张訂章相互依存性与贸易的好处|当每个人专门生产自己有比较优势的物品时，经济的总产量就增加了。

贸易町以使社会上每个人都获益，因为它使人们町以专门从事他们具冇比较优势的活动。

第2篇市场如何运行环■章供给与需求的両珈完全竞争市场必须具备两个特征：1.可供销售的物品时完全相同的；2.买者和卖者人数众多，以至于没有任何一个买者或卖者可以影响市场价格。

•影响买者的变屋：价格、收入、相关物品的价格、嗜好、预期、买者的数量。

Chapter 5Elasticity and its applicationSolutions to text problemsprice elasticity of demand. Explain the relationship between total QZ Definerevenue and the price elasticity of demand. (page 92)The price elasticity of demand is a measure of how much the quantity demanded of a good responds to a change in the price of that good, calculated as the percentage change in quantity demanded divided by the percentage change in price.The relationship between total revenue and the price elasticity of demand is: (1) when a demand curve is inelastic (a price elasticity less than 1), a price increase raises total revenue, and a price decrease reduces total revenue; (2) when a demand curve is elastic (a price elasticity greater than 1), a price increase reduces total revenue, and a price decrease raises total revenue; and (3) when a demand curve is unit elastic (a price elasticity equal to 1), a change in price does not affect total revenue.price elasticity of supply. Explain why the price elasticity of supply QZ Definemight be different in the long run than in the short run. (page 94)The price elasticity of supply is a measure of how much the quantity supplied of a good responds to a change in the price of that good, calculated as the percentage change in quantity supplied divided by the percentage change in price.The price elasticity of supply might be different in the long run than in the short run because over short periods of time, firms cannot easily change the size of their factories to make more or less of a good. Thus, in the short run, the quantity supplied is not very responsive to the price. However, over longer periods, firms can build new factories or close old ones, or they can enter or exit a market. So, in the long run, the quantity supplied can respond substantially to the price.QZ How might a drought that destroys half of all farm crops be good for farmers? If such a drought is good for farmers, why don’t farmers destroy their own crops in the absence of a drought? (page 100)A drought that destroys half of all farm crops could be good for farmers if the demand for the crops is inelastic. The shift to the left of the supply curve leads to a price increase that raises total revenue because the price elasticity is less than one.Even though a drought could be good for farmers, they wouldn’t destroy their crops in the absence of a drought because no one farmer would have an incentive to destroy her crops, since she takes the market price as given. Only if all farmers destroyed their crops together, for example through a government program, would this plan work to make farmers better off.Questions for review (page 101)1The price elasticity of demand measures how much the quantity demanded responds to a change in price. The income elasticity of demand measures how much the quantity demanded changes as consumer income changes.2The determinants of the price elasticity of demand include whether the good is a necessity or a luxury, how available close substitutes are, how broadly defined the market is, and the time horizon.Luxury goods have greater price elasticity than necessities, goods with close substitutes have greater elasticity, goods in more narrowly defined markets have greater elasticity, and goods have greater elasticity the longer the time horizon.3Elasticity greater than 1 means demand is elastic. When the elasticity is greater than 1, the percentage change in quantity demanded exceeds the percentage change in price. When the elasticity60 Principles of Economics, Third edition, Instructor’s Manualequals 0, demand is perfectly inelastic. There is no change in quantity demanded when there is a change in price.4Figure 5.1 presents a supply-and-demand diagram, showing equilibrium price, equilibrium quantity, total spending by consumers and the total revenue received by producers. Total spending byconsumers equals the equilibrium price times the equilibrium quantity. Total revenue received by producers also equals the equilibrium price times the equilibrium quantity. These are shown by the area of the rectangle in Figure 5.1.Figure 5.15If demand is elastic, an increase in price reduces total revenue. With elastic demand, the quantity demanded falls by a greater percentage than the percentage increase in price. As a result, total revenue declines.6 A good with an income elasticity less than 0 is called an inferior good because as income rises, thequantity demanded declines.Chapter 5: Elasticity and its application 61 7The price elasticity of supply is calculated as the percentage change in quantity supplied divided by percentage change in price.Price elasticity of supply =% change in quantity supplied % change in priceIt measures how much the quantity supplied responds to changes in the price.8The price elasticity of supply of Picasso paintings is zero, since no matter how high price rises, no more can ever be produced.9The price elasticity of supply is usually larger in the long run than it is in the short run. Over short periods of time, firms cannot easily change the size of their factories to make more or less of a good, so the quantity supplied is not very responsive to price. Over longer periods, firms can build new factories or close old ones, so the quantity supplied is more responsive to price.10OPEC was unable to maintain a high price through the 1980s because the elasticity of supply and demand were more elastic in the long run. When the price of oil rose, producers of oil outside of OPEC increased oil exploration and built new extraction capacity. Consumers responded withgreater conservation efforts. As a result, supply increased and demand fell, leading to a lower price for oil in the long run.Problems and applications (page 102)1 a Mystery novels have more elastic demand than required textbooks, because mystery novels haveclose substitutes and are more of a luxury good, while required textbooks are more of a necessity with no close substitutes. If the price of mystery novels were to rise, readers could substituteother types of novels, or buy fewer novels altogether. But if the price of required textbooks were to rise, students would have little choice but to pay the higher price. Thus the quantity demanded of required textbooks is less responsive to price than the quantity demanded of mystery novels.b Beethoven recordings have more elastic demand than classical music recordings in general.Beethoven recordings are a narrower market than classical music recordings, so it is easy to find close substitutes for them. If the price of Beethoven recordings were to rise, people couldsubstitute other classical recordings, like Mozart. But if the price of all classical recordings were to rise, substitution would be more difficult. A transition from classical music to hip-hop, forexample, is less likely. Thus the quantity demanded of classical recordings is less responsive to price than the quantity demanded of Beethoven recordings.c Heating oil during the next 5 years has more elastic demand than heating oil during the next 6months. Goods have a more elastic demand over longer time horizons. If the price of heating oil were to rise temporarily, consumers couldn’t switch to other sources of fuel without greatexpense. But if the price of heating oil were to be high for a long time, people would gradually switch to gas or electric heat. As a result, the quantity demanded of heating oil during the next 6 months is less responsive to price than the quantity demanded of heating oil during the next 5years.d Lemonade has more elastic demand than water. Lemonade is a luxury with close substitutes,while water is a necessity with no close substitutes. If the price of water were to rise, consumers have little choice but to pay the higher price. But if the price of lemonade were to rise,consumers could easily switch to other soft drinks. So the quantity demanded of lemonade ismore responsive to price than the quantity demanded of water.2 a(i) For business travellers, the price elasticity of demand when the price of tickets risesfrom $200 to $250 is [(2,000 – 1,900)/1,950]/[(250 – 200)/225] = 3/13 = 0.23.(ii) For holiday-makers, the price elasticity of demand when the price of tickets risesfrom $200 to $250 is [(800 – 600)/700] / [(250 – 200)/225] = 9/7 = 1.29.b The price elasticity of demand for holiday-makers is higher than the elasticity for businesstravellers because holiday-makers can more easily choose a different mode of transportation like driving or taking the train. Business travellers are less likely to do so since time is moreimportant to them and their schedules are less adaptable.62 Principles of Economics, Third edition, Instructor’s Manual3 a(i) If your income is $10,000, your price elasticity of demand as the price of compactdiscs rises from $8 to $10 is [(40 – 32)/36] / [(10 – 8)/9] = 1(ii) If your income is $12,000, the elasticity is [(50 – 45)/47.5] / [(10 – 8)/9] = 9/19 =0.47b(i) If the price is $12, your income elasticity of demand as your income increases from $10,000 to $12,000 is [(30 – 24)/27] / [(12,000 – 10,000)/11,000] = 11/9 = 1.22.(ii) If the price is $16, your income elasticity of demand as your income increases from $10,000 to $12,000 is [(12 – 8)/10] / [(12,000 – 10,000)/11,000] = 11/5 = 2.2.4 a If Emily always spends one-third of her income on clothing, then her income elasticityof demand is one, since maintaining her clothing expenditures as a constant fraction ofher income means the percentage change in her quantity of clothing must equal herpercentage change in income. For example, suppose the price of clothing is $30, herincome is $9,000, and she purchases 100 clothing items. If her income rose 10 percentto $9,900, she’d spend a total of $3,300 on clothing, which is 110 clothing items, a 10percent increase.b Emily’s price elasticity of clothing demand is also one, since every percentage point increase inthe price of clothing would lead her to reduce her quantity purchased by the same percentage.Again, suppose the price of clothing is $30, her income is $9,000, and she purchases 100clothing items. If the price of clothing rose 1 percent to $30.30, she would purchase 99 clothing items, a 1 percent reduction. Note this part of the problem can be confusing to students if theyhave an example with a larger percentage change and they use the point elasticity calculationmethod. This example can be used to further illustrate the usefulness of the midpoint method for any size change.c Since Emily spends a smaller proportion of her income on clothing, then for any given price, herquantity demanded will be lower. Thus her demand curve has shifted to the left. But becauseshe’ll again spend a constant fraction of her income on clothing, her income and price elasticities of demand remain one.5 a With a 4.3 percent decline in quantity following a 20 percent increase in price, theprice elasticity of demand is only 4.3/20 = 0.215, which is fairly inelastic.b With inelastic demand, the revenue rises when the fare rises.c The elasticity estimate might be unreliable because it’s only the first month after the fareincrease. As time goes by, people may switch to other means of transportation in response to the price increase. So the elasticity may be larger in the long run than it is in the short run.6Tom’s price elasticity of demand is zero, since he wants the same quantity regardless of the price.Jerry’s price elasticity of demand is one, since he spends the same amount on gas, no matter what the price, which means his percentage change in quantity is equal to the percentage change in price.7To explain the observation that spending on restaurant meals declines more during economic downturns than does spending on food to be eaten at home, economists look at the income elasticity of demand. In economic downturns, people have lower income. To explain the observation, the income elasticity of restaurant meals must be larger than the income elasticity of spending on food to be eaten at home.8 a With a price elasticity of demand of 0.4, reducing the quantity demanded of cigarettes by 20percent requires a 50 percent increase in price, since 20/50 = 0.4. With the price of a pack ofcigarettes currently at $8, this would require an increase in the price to $13.33 a pack using the midpoint method (note that ($13.33 – $8)/$10.67 = 0.50).b The policy will have a larger effect five years from now than it does one year from now. Theelasticity is larger in the long run, since it may take some time for people to reduce theircigarette usage. The habit of smoking is hard to break in the short run.c Since teenagers don’t have as much income as adults, they are likely to have a higher priceelasticity of demand.9You’d expect the price elasticity of demand to be higher in the market for vanilla ice cream than for all ice cream because vanilla ice cream is a narrower category and other flavours of ice cream are almost perfect substitutes for vanilla.Chapter 5: Elasticity and its application 63 You’d expect the price elasticity of supply to be larger for vanilla ice cream than for all ice cream. A producer of vanilla ice cream could easily adjust the quantity of vanilla ice cream and produce other types of ice cream. But a producer of ice cream would have a more difficult time adjusting the overall quantity of ice cream they produced.10 a As Figure 5.2 shows, in both markets, the increase in supply reduces the equilibrium price andincreases the equilibrium quantity.b In the market for pharmaceutical drugs, with inelastic demand, the increase in supply leads to arelatively large decline in the price and not much of an increase in quantity. This marketexperiences a larger change in price.Figure 5.2c In the market for computers, with elastic demand, the increase in supply leads to a relativelylarge increase in quantity and not much of a decline in price. This market experiences a largerchange in quantity.d In the market for pharmaceutical drugs, since demand is inelastic, the percentage increase inquantity will be less than the percentage decrease in price, so total consumer spending willdecline. In contrast, since demand is elastic in the market for computers, the percentage increase in quantity will be greater than the percentage decrease in price, so total consumer spending will increase.11 a As Figure 5.3 shows, in both markets, the increase in demand increases both the equilibriumprice and the equilibrium quantity.b In the market for beachfront resorts, with inelastic supply, the increase in demand leads to arelatively large increase in the price and not much of an increase in quantity. This marketexperiences a larger change in price.c In the market for cars, with elastic supply, the increase in demand leads to a relatively largeincrease in quantity and not much of an increase in price. This market experiences a largerchange in quantity.d In both markets, total consumer spending rises, since both equilibrium price and equilibriumquantity rise.64 Principles of Economics, Third edition, Instructor’s Manual Figure 5.3Quantity of cars 12 a Vineyard owners whose vines weren’t destroyed benefited because the destruction of some ofthe vines reduced the supply, causing the equilibrium price to rise.b To tell whether vineyard owners as a group were hurt or helped by the floods, you’d need toknow the price elasticity of demand. It could be that the additional income earned by vineyard owners whose vines weren’t destroyed rose more because of the higher prices than the lossesmade by vineyard owners whose vines were destroyed, if demand is inelastic.13 A worldwide drought could increase the total revenue of farmers if the price elasticity of demand forgrain is inelastic. The drought reduces the supply of grain, but if demand is inelastic, the reduction of supply causes a large increase in price. Total farm revenue would rise as a result. If there’s only a drought in Queensland, Queensland’s production isn’t a large enough proportion of the total farm product to have much impact on the price. As a result, price is basically unchanged, while the output of Queensland farmers declines, thus reducing their income.14 When productivity increases for all farmland at a point in time, the increased productivity leads to arise in farmland prices, since more output can be produced on a given amount of land. But prior to the technological improvements, the productivity of farmland depended mainly on the prevailing weather conditions. There was little opportunity to substitute land with worse weather conditions for land with better weather conditions. As technology improved over time, it became much easier to substitute one type of land for another. So the price elasticity of supply for farmland increased over time, since now land with bad weather is a better substitute for land with good weather. Theincreased supply of land reduced farmland prices. As a result, productivity and farmland prices are negatively related over time.15 Not necessarily. If demand for luxury cars is price elastic, then raising the price of luxury cars byincreasing the tax will decrease the total revenue from luxury cars. It is likely that demand for luxury cars is elastic as they are more of a luxury than a necessity. P r i c e o f c a r s。

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。