经济学原理课后习题参考答案

政府为了抑制通货膨胀会减少流通中的货币量，人们可用的货币量减少,但商品价格在短期内具有粘性仍居

高不下，于是社会消费的商品和劳务量减少，消费量不足又会引起企业开工不足，导致失业。失业率高，通

胀率低;失业率低，通胀率高。通货膨胀和失业之间是此消彼长、相互交替的关系。

1.描述下列每种情形中当事人面对的权衡：

a.某个家庭决定是否购买一辆新车；a tradeoff between the cost of the car and other things they might want to buy.

b.国会成员决定对国家公园拨多少款the tradeoff is between parks and other spending items or tax cuts.（不增加拨款可少征税）

c.公司总裁决定是否建个新工厂；the decision is based on whether the new factory will increase the firm's profits compared to other alternatives. （upgrade existing equipment or expand existing factories）

increase profit the most

d.某个教授决定用多少时间备课between the value of improving the qualityof the lecture compared to

other things she could do with her time, such as working on additional research.

e.刚毕业的大学生决定是否读研究生

2.你正决定是否去度假。度假的大部分成本（机票、住宿费和放弃的工资）是用货币衡量

的，但度假的收益是心理上的。你如何比较度假的收益和成本？

two ways：https://www.360docs.net/doc/2218802063.html,pare the vacation with what you would do in its place。decide if you'd rather have the new clubs or the vacation.

2. think about how much work you had to do to earn the money to pay for the vacation

3.你正打算周六去做兼职，但你朋友让你去滑雪。去滑雪的真实成本是什么？现在假设你

本来打算周六在图书馆学习。在这种情形下，去滑雪的成本是什么？请解释。

its monetary and time costs, which includes the opportunity cost of the wages you are giving up by not working.

4.你在篮球比赛博彩中赢了100 元。对于这笔钱你有两个选择，你可以现在就花掉或者存

入银行，银行利率为5%，你现在就将这笔钱花掉的机会成本是多大？

you are giving up the opportunity to spend $105 a year from now.

5.你管理的公司已经投资500 万元开发某个新产品，但研发尚未结束。在最近一次会议上，

销售人员向你报告说由于竞争产品上市，该产品的期望销售额下降为300 万元。如果你还需

要再投入100 万元才能完成该产品的研发，你会继续下去吗？为了完成研发，你最多愿意支

付多杀钱？

$5 million is the sunk cost. What matters now is the chance to earn profits at the margin.

If you spend another $1 million and can generate sales of $3 million, you'll earn $2 million in marginal profit,

so you should do so.

In fact, you'd pay up to $3 million；any more than that, and you won't be increasing profit at the margin.

6.社会保障系统为年龄超过65 岁的老人提供收入。如果接受救济的某个老人决定去工作

以争取部分收入，那么他从社会保障得到的钱数通常就会减少。

a.提供社会保障对人们在工作期间（年轻时）的储蓄激励有何影响？

lowers an individual’s incentive to save for retirement.

The benefits provide some level of income to the individual when he or she retires. individual is not

entirely dependent on savings to support consumption through the years in retirement.

b.收入较高时保障金会下降，这对65 岁以上老人的工作激励有何影响？

an incentive not to work (or not work as much) after age 65.

Because the more you work, the lower your after-tax Social Security benefits will be.

7.某法案于1996 年实施，它对美国联邦政府反困项目进行了改革，新法案规定某些被

救助者只能领取两年的救济金。

a.这种改革对穷人的工作激励有何影响？

they have greater incentive to find jobs

b.这种改革对平等和效率之间的权衡有何影响（更侧重于效率还是平等）？

the change in the law is one that increases efficiency but reduces equity.

someone who can't find a job will get no income at all, so the distribution of income will become less equal.

But the economy will be more efficient, since welfare recipients have a greater incentive to find jobs.

8.你的室友做得饭菜比你好吃，但你打扫卫生的速度比他快。如果你的室友只做饭而你只打扫卫生，这比你

们各干各的家务花费更多还是更少时间？再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更好。By specializing, you reduce the total time spent on chores.（家庭杂务）

countries can specialize and trade, making both better off.

EX. make clothes and make wine efficiently s produce all the clothes and French workers produce all the wine, and they exchange some wine for some clothes.

9.解释下列每一项政府行为的出发点是更关注平等还是更关注效率。如果是更关注效率，分析可能涉及的市

场失灵情形。

a.管制有线电视价格；

b.为某些穷人提供购买食品时可做钱使用的食品券；

c.在公共场所禁止吸烟；

d.将标准石油公司（该石油公司一度拥有美国90%的炼油厂）拆分成几家小公司；

e.对高收入人群征收较高的个人所得税；

c. Efficiency: An externality arises because secondhand smoke harms nonsmokers.

d. Efficiency: The market failure occurs because of Standard Oil's monopoly power.

e. Equity

f. Efficiency: There is an externality because of accidents caused by drunk drivers.

10.从平等和效率角度讨论下面每种说法。

a.“应该保证社会中的每个人得到最好的医疗服务。”

Efficiency? currently doctors form a monopoly and restrict health care to keep their incomes high,so efficiency would increase by providing more health care.

if the government mandated increased spending on health care, the economy would be less efficient because it would give people more health care than they would choose to pay for.

From the point of view of equity, poor people are less likely to have adequate health care, an improvement. Each person would have a more even slice of the economic pie, though the pie would consist of more health care and less of other goods.

b.“工人在被解雇后，应该允许他们在找到新工作前一直领取失业保险金。”

there’s a tradeoff between equity and efficiency.

When workers are laid off, equity considerations argue for the unemployment benefits system to provide them with some income until they can find new jobs.

But there’s an efficiency problem? The economy isn’t operating efficiently if people remain unemployed for a long time, and unemployment benefits encourage unemployment.

So greater equity reduces efficiency

11.你的生活水平和你父母和祖父母在你这般大时的生活水平，有哪些不同？为何能发生这些变化？

average income has increased over years, have a better standard of living than our parents, and a much better standard of living than our grandparents.

Cause: increased productivity: t an hour of work produces more goods and services than it used to Thus incomes have continuously risen over time, as has the standard of living.

12.假设美国人决定将他们的收入多储蓄一些。如果银行将多出的这部分储蓄借给商人，

商人用这些钱建立工厂，这种做法如何加快了生产力的增长？你认为谁从较高的生产力中得到了好处？社会

能得到免费的午餐吗？

the same number of workers will have more equipment to work with.

the workers, get more payment since they're producing more

the factory owners get a return on their investments.

There is no such thing as a free lunch, however, because when people save more, they are giving up spending. They get higher incomes at the cost of buying fewer goods.市场需求降低，生产的商品销售不出去，市场会陷

入疲软，企业利润减少，会通过减少产量和裁减工人降低成本，社会经济会减缓甚至停滞。所以高储蓄换来

的生产率提高只会使社会暂时获益无法持久。

13. 2010 年，美国总统巴拉克.奥巴马和美国国会制定并通过了美国医疗服务改革法案。该法案有两个目的，一是为更多的美国人提供医疗保险（方法是对美国高收入家庭征税然后用于补贴低收入家庭），二是降低医

疗服务的成本（方法是对医疗服务提供系统进行各种改革）。

a.这些目的如何与平等和效率相关？

通过向高收入家庭征税来对低收入家庭的补贴筹资，使更多的低收入人群能享受到医疗保险得到更好的治疗，有助于改善社会的收入分配增进公平；

通过对医疗的提供方式进行改革降低医疗成本，更多的产出被用于医疗方面，提高了医疗产业的效率。

b.为何医疗服务改革法案可能增加美国的生产力？

.对医疗提供方式进行多种改革，提供多种灵活的医疗方式，更有效地利用了医疗领域的资源，促进更多产出，提高了美国的生产率。

c.为何医疗服务改革法案可能降低美国的生产力？

医疗改革通过向高收入家庭征税补贴低收入家庭，让更多的美国人获得医疗保险，但因为每个人都能接受较

好的医治，人们不会再为争取更好的医疗条件而努力工作，从而会降低社会的生产率

the economy would be less efficient because it would give people more health care than they would choose to pay for.

14. 在美国革命战争期间，美国各个殖民地无法筹集足够的税收资金来支持战争；为了弥补资金缺口，它们

决定印刷发行更多的货币，这种做法有时称为“通货膨胀税”。当货币发行过多时，是向谁“征税”？为什么？

持有货币者被“征税”了。因为货币增加造成物价水平上升，货币的实际价值降低，每一单位美元的购买力

下降。货币增加使得持有货币者的财富缩水，所能购买的商品和劳务数量减少，就像是向每个持有货币的人

征了税，引发了通货膨胀。16. 通过增加公民的税收来支付新机场的建设费用，短期来说会增加公民负

担，减少经济中的支出，导致失业率的上升及物价的下降；长期来看，新机场的建成为公民提供更多的便利和服务，从而可以提供啊社会的效率。

15.假设你是个政策制定者，你正在决定是否降低通货膨胀率。为了做出明智的决策，你应该了解有关通货膨胀、失业及二者之间权衡的哪些知识？

Any attempt to reduce inflation will likely lead to higher unemployment in the short run.

what causes inflation and unemployment,

what determines the tradeoff between them. 通货膨胀和失业各自对经济产生的影响多大以及抑制通货膨胀(reduce inflation )的措施对失业率的影响程度、持续时间等。

A policymaker thus faces a tradeoff between the benefits of lower inflation compared to the cost of higher unemployment.

16.某个政策制定者正在决定如何为新机场的建设项目筹资。他可以使用向市民征税的方法或者使用发行更多货币的方法。说说每种方法的可能的短期结果和长期结果。

Raising taxes will lead to reducing spending in the economy. This will cause a short-run increase in unemployment and a drop in prices.

However, printing more money will cause a long-run rise inflation because the value of money will be lowered. Unit2

1.画出一个循环流向图。指出与下列每种活动相伴的产品和服务流向以及货币流向。

a.赛琳娜（Selena）向小卖部主人支付1 元钱购买了一夸脱牛奶。

b.司徒雷登（Stuart）在快餐店工作，每小时挣4.50 元。

c.珊娜（Shanna）花了30 元钱理发。

d.珊莉（Sally）因拥有阿克姆企业10%的产权而赚取了10,000 元。

2.某个社会生产军用品与民用消费品，我们分将它们称为“枪炮”和“黄油”。

a.画出枪炮和黄油的生产可能性边界。使用机会成本的概念解释为什么这一曲线是向外弓起的。

Figure 6 shows a production possibilities frontier between guns and butter. It is bowed out because the opportunity cost of butter depends on how much butter and how many guns the economy is

producing. When the economy is producing a lot of butter, workers and machines best suited to

making guns are being used to make butter, so each unit of guns given up yields a small increase in the production of butter. Thus, the frontier is steep and the opportunity cost of producing butter is high.

When the economy is producing a lot of guns, workers and machines best suited to making butter are being used to make guns, so each unit of guns given up yields a large increase in the production of

butter. Thus, the frontier is very flat and the opportunity cost of producing butter is low.

c.在图中找到该经济无法实现的一点。再找到一个可行但无效率的点。

c.假设该社会有两个政党，分称为鹰党（他们想要强大的军事）和鸽党（他们想要较小的军事）。在你的生产可能性边界上找到鹰党可能选择的一个点和鸽党可能选择的一个点。

d.假设具有侵略性的领国降低了自己的军事规模。结果，鹰党和鸽党都减少了原本想生产的枪炮数量，假设两党的枪炮减少量相同。用黄油的产量增加量衡量，哪一个政党得到了更大的“和平红利（peace dividend）”？请解释。

3.第1 章讨论的第一个经济学原理是人们面对权衡。使用生产可能性边界说明社会在下列两种“商品”上的权衡：一是清洁的环境，二是企业产品产量。你认为是什么因素决定了这一边界的形状和位置？如果工程师发明了一种新的发电方法，这种方法产生的污染较少，那么生产可能性边界将会发生什么变化？

The shape and position of the frontier depend on how costly it is to maintain a clean environment?the productivity of the environmental industry.

4.某个经济由三个人组成：拉里（Larry）、摩尔（Moe）和克莉（Curly）。每人每工作

10 小时，他们生产两种服务：割草和洗车。在一小时内：拉里可以割1 块草坪或洗1 辆车；摩尔可以割

1 块草坪或洗

2 辆车；克莉可以割2 块草坪或洗1 辆车。

a.计算下列每种情形下生产的每种服务数量，我们将这四种情形分记为A、B、C、D。

所有三个人将所有时间用于割草。（A）

所有三个人将所有时间用于洗车。（B）

所有三个人将一半的时间用于割草、一半时间用于洗车。（C）

拉里的一半时间用于割草、一半时间用于洗车；而摩尔只洗车，克莉只割草。(D)

b.画出这个经济的生产可能性边界。使用你在（a）部分的答案，在图中标记出A、B、C 和D 点。

c.解释该经济的生产可能性边界为何具有你画出的那种形状？

d. 你在（a）部分计算的四个配置中，哪个（些）为无效率的配置？请解释。

5.将下列主题分归入微观经济学或宏观经济学。

a.家庭制定把多少收入用于储蓄的决策

b.政府对汽车排放污染管制的效应

c.国民的高储蓄对经济增长的影响

d.企业制定雇佣多少工人的决策

e.通货膨胀率和货币量变动之间的关系

6.将下列每个陈述分归入实证性陈述或规范性陈述。请解释原因。

a.社会面对通货膨胀和失业的短期权衡 a positive statement It deals with how the economy i，not how it should be.

there is a short-run negative relationship between inflation and unemployment, the statement is a fact, thus it is a positive statement.

b.降低货币增长率将导致通货膨胀率下降The statement tells how the world is, and so it is a positive statement.

c.美国联邦储备银行应该降低货币增长率

d.社会应该要求领取救济金的人去找工作It states an opinion about something that should be done, not how the world is.

e.降低税率可以鼓励人们多工作多储蓄

s a positive statement.

the relationship between tax rates and work, as well as the relationship between tax rates and saving is negative in both cases. So the statement reflects how the world is, and is thus a positive statement.

7.如果你是总统，你对你的经济顾问提出的实证性观点还是规范性观点更感兴趣？为什么？

be interested in both, but probably be most interested in their positive views.

Economists know many facts about the economy and the interaction of different sectors. So you would be most likely to call on them about questions of fact?positive anal ysis.

president has to make the normative statements as to what should be done, with an eye to the political consequences. The normative statements made by economists represent their own views, not necessarily your views or the electorate’s views.

Unit3

1.玛利亚（Maria）在1 小时内可以学习20 页经济学教科书。她在1 小时内也能学习50页的社会学教科书。她每天学习时间为5 个小时。

a.画出玛利亚学习经济学和社会学的生产可能性边界。

b.玛利亚学习100 页社会学的机会成本是什么？

40 pages of economics.

2.每个美国人或日本人每年都可以生产4 辆汽车。每个美国人每年可以生产10 吨谷物，而每个日本人每年可以生产5 吨谷物。为简单起见，假设每个国家都有1 亿人。100 million

a.仿照教材图1 中的表，画出表述上述情形的表。

b.分画出美国经济和日本经济的生产可能性边界。

c.美国生产1 辆汽车和1 吨谷物的机会成本分为多少？日本呢？仿照教材图1 中的表，画表总结这些信息。

d.哪个国家在汽车的生产上具有绝对优势？neither哪个国家在谷物的生产上具有绝对优势？the United States

e.哪个国家在汽车的生产上具有比较优势？哪个国家在谷物的生产上具有比较优势？

Japan has a comparative advantage in producing cars, since it has a lower opportunity cost in terms of grain given up.(两个国家之间的比较)

The United States has a comparative advantage in producing grain, since it has a lower opportunity cost in terms of cars given up.

f.如果不进行交易，假设两个国家都用一半人口生产汽车、一半人口生产谷物。分求出每个国家的汽车和谷物的产量。

g.在交易前的生产可能性边界上任找一点，说明交易会使每个国家的状况变得更好。

suppose the United States changed 1 worker from producing cars to producing grain. Japan changes 1 worker from producing grain to producing cars. That worker would produce 4 more cars and 5 fewer tons of grain.

suppose the United States offers to trade 7 tons of grain to Japan for 4 cars. The United States will do this because it values 4 cars at 10 tons of grain, so it will be better off if the trade goes through. Japan will take the trade because it values 4cars at 5 tons of grain, so it will be better off.

With the trade and the change of 1 worker in both the United States and Japan, each country gets the same amount of cars as before and both get additional tons of grain (3 for the United States and 2 for Japan).

Thus by trading and changing their production, both countries are better off.

3.帕特(Pat)和克丽丝(Kris)是室友。她们大部分时间用在学习上，小部分时间用于她们喜爱的活动上：做比萨饼和麦根汽水（root beer）。帕特制造一单位汽水需要4 小时、制造一单位比萨需要2 小时。克丽丝制造一单位汽水需要6 小时、制造一单位比萨需要4 小时。

a.求每人制造一单位比萨饼的机会成本。谁在比萨生产上具有绝对优势？Pat谁在比萨生产上具有比较优势？Pat

b.如果她们进行交易，谁会用比萨饼换取对方的汽水？Pat, since she has a comparative advantage in making pizza

c.比萨的价格可用汽水的数量衡量。求能使两个人状况都变好的比萨最高交易价格和最低交易价格。请

解释。

The highest price of pizza is 2/3 of a gallon of root beer.

The lowest price of pizza is 1/2 of a gallon of root beer.

4.假设加拿大有1000 万工人，每个工人每年可以生产2 单位的汽车或30 单位的麦子。

a.加拿大生产1 单位汽车和1 单位麦子的机会成本分是什么？解释这两种产品机会成本之间的关系。

15 bushels of wheat. 1/15 of a car

b.画出加拿大的生产可能边界。如果加拿大选择消费1000 万单位汽车(先生产)且不进行交易，它能生

产多少小麦？在生产可能性边界上标注出该点。

Since the tradeoff between cars and wheat is always the same, the production possibilities frontier is a straight line.

d.现在假设美国愿意从加拿大购买1000 万单位汽车，每辆车的购买价为20 单位小麦。如果加拿大仍然

消费1000 万单位汽车，这个买卖能让加拿大消费多少小麦？在你画出的生产可能性边界上标出这一点。

加拿大应该接受这个买卖吗？

（美国不给钱的情况）If the United States buys 10 million cars from Canada and Canada continues to consume 10 million cars, then Canada will need to produce a total of 20 million cars. So Canada will be producing at the vertical intercept（纵截距）of the production possibilities frontier.

But if Canada gets 20 bushels of wheat per car, it will be able to consume 200 million bushels of wheat, along with the 10 million cars. This is shown as point B in the figure. Canada should accept the deal because it gets

the same number of cars and 50 million more bushes of wheat.（所有加拿大人都去生产汽车）

5.英格兰和苏格兰都生产烤饼和毛衣。假设每个英格兰工人每小时可以生产50 个烤饼或1件毛衣。每个苏格兰工人每小时可以生产40 个烤饼或2 件毛衣。

a.在每种产品的生产上，哪个国家具有绝对优势？哪个国家具有比较优势？

Absolute advantage: Scones English workers sweater Scottish workers

Comparative advantage: Scones English workers sweater Scottish workers

Comparative advantage runs the same way.

c.如果英格兰和苏格兰决定进行交易，苏格兰将用自己生产的哪种产品交换英格兰的哪种产品？请解释。

Scotland will produce sweaters and trade them for scones produced in England.

A trade with a price between 20 and 50 scones per sweater will benefit both countries, as they'll be

getting the traded good at a lower price than their opportunity cost of producing the good in their own country

d.如果每个苏格兰工人每小时只能生产1 件毛衣，苏格兰仍能从贸易中得到好处吗？请解释。

Scotland would still have a comparative advantage in producing sweaters. t there are still gains from trade since England has a higher opportunity cost

7.假设每个美国人每年可以生产100 件衬衫或20 台计算机，而每个中国人每年可以生产100 件衬衫和

10 台计算机。

a.分画出两个国家的生产可能性边界。假设不存在交易时，每个国家在两种产品的生产上各花费一半的

时间。在生产可能性边界上画出这样的点。

b.如果这两个国家进行贸易，哪个国家将出口衬衫？用数字举例说明并在你的图上画出。哪个国家会从

交易中获益？请解释。

c.找出可行的计算机交易价格区间并解释（计算机价格用衬衫数量衡量）。

d.假设中国的生产力赶上了美国，所以每个中国人每年可以生产100 件衬衫或20 台计算机。请你预

测一下可能的交易模式。中国这一生产力的提高如何影响两个国家居民的状况？

假设中国生产率赶上了美国，由于两国的生产效率完全相同，所以贸易产生的基础不论是比较优势还是绝对

优势就不复存在，这时中美之间的贸易就会消失

9.判断下列说法正误并进行解释。

a.“即使一国在所有产品的生产上都具有绝对优势，若它与国贸易则两国都能从贸易中得到好处。”T All that's necessary is that each country have a comparative advantage in some good.

b.“天才们在所从事的每件事情上都具有比较优势。” F

Comparative advantage reflects the opportunity cost of one good or activity in terms of another. If you have a comparative advantage in one thing, you must have a comparative disadvantage in the other thing.

c.“如果某交易对交易一方有好处，那么该交易就不能对交易另一方有好处。”F

Trades can and do benefit both sides?especially trades based on comparative advantage. If both sides

didn't benefit, trades would never occur

d.“如果某交易对交易一方有好处，那么该交易对交易另一方也总是有好处的。”

F the trade price must lie between the tow opportunity costs to be good for both parties.

e.“如果某交易对一国有好处，那么该交易必定对该国家的每个人都有好处。”

F

trade that makes the country better off can harm certain individuals in the country. For example, suppose a country has a comparative advantage in producing wheat and a comparative disadvantage in producing cars. Exporting wheat and importing cars will benefit the nation as a whole, as it will be able to consume more of

both goods. However, the introduction of trade will likely be harmful to domestic auto workers and manufacturers.

10.美国向世界其他国家出口玉米和飞机，从世界其他国家进口石油和衣服。你认为这种交易模式符合比较

优势原理吗？为什么符合或为什么不符合？

11.比尔和希拉是一家人，他们都生产食品和衣服。在1 小时内，比尔可以生产1 单位食品或1 单位衣服，而希拉里能生产2 单位食品和3 单位衣服。他们每人每天工作10 小时。

c.假设一人每天在每种产品上生产时间与另一人相同，画出该家庭的生产可能性边界。

d.现在希拉里提议由她专业生产衣服。也就是说，她将为家庭生产全部衣服。如果她将全部时间用于生

产衣服，衣服仍不够家庭所用，那么比尔也会生产一部分衣服。现在，该家庭的生产可能性边界是什么样子的？

e.比尔建议由希拉里专业从事食品的生产。也就是说，希拉里为家庭生产所有的食品。如果希拉里将她

的全部时间用于食品生产，但食品仍不够家庭所用，那么比尔也会生产一部分食品。现在，该家庭的生产可

能性边界是什么样子的？

f.比较一下你对于问题(c)、(d)、(e)的答案，然后使用比较优势原理判断哪种时间配置方式是最合理的。

b. Bill has a comparative advantage in the production of food because he has a lower opportunity cost (1 unit of clothing per unit of food) than Hillary (1.5 units of clothing per unit of food).

Figure 6

c. See Figure 6. If Bill and Hillary spend all of their time producing food, they can produce 30 units [(10 ? 1) + (10 ? 2)] per day. If they spend all of their time producing clothing, they can produce 40 units per day [(10 ? 1) + (10 ? 3)].

e.If no clothing is produced, Bill and Hillary can still produce only 30 units of food. If Hillary switches to

clothing production, the household gives up 2/3 unit of food for every unit of clothing produced. When Hillary’s 10 hours are devoted to producing clothing, she wo uld be producing 30 units of clothing while Bill is producing 10 units of food.

Of course, if Bill then begins to produce clothing, the household gives up 1 unit of food for each unit of clothing produced. Bill and Hillary could devote all their time to producing clothes. If they choose to do so, they can produce 40 units. Their production possibilities frontier is shown in Figure 7.

(为折线)

Figure 7

e. Again, Hillary and Bill can chose to produce no clothing and produce all food (30 units). To gain some clothing, Bill would produce clothing, sacrificing 1 unit of food for each unit of clothing produced. If Bill spends all of his time producing food, he would produce 10 units, while Hillary produced 20 units of food. To gain additional clothing, the household would need Hillary to reallocate her time away from food production toward clothing production (at a cost of 1/2 unit of food for each unit of clothing produced). If they choose to produce only clothing, they can produce 40 units of clothing. See Figure 8.

Figure 8

f. It is clear that the production possibilities expand when Hillary specializes in the production

of clothing. This makes sense because she has a comparative advantage in the production of clothing.

Unit4

1.使用供给和需求图解释下列论断。

c.“当中东地区的战争爆发时，汽油价格上升，凯迪拉克汽车价格下降。”

Since much oil production takes place there, the war disrupts oil supplies, shifting the supply curve for gasoline to the left,

With a higher price for gasoline, the cost of operating a gas-guzzling automobile, like a Cadillac, will increase. As a result, the demand for used Cadillacs will decline, as people in the market for cars will not find Cadillacs as attractive. In addition, some people who already own Cadillacs will try to sell them. The result is that the demand curve for used Cadillacs shifts to the left, while the supply curve shifts to the right, as shown

in Figure 9.

2. “笔记本需求增加，提高了笔记本的需求量但不会提高笔记本的供给量。”这个论断正确吗？请

解释。

False

As Figure 10 shows, the increase in demand for notebooks results in an increased quantity supplied. The only way the statement would be true is if the supply curve was a vertical line, as shown in Figure 11

3. 考虑大型家庭汽车（minivans）的市场。对于下列事件，分指出它影响的是需求或供给的哪个决

定因素？你还要指出需求或供给是增加了还是减少了。然后画图说明它对大型家庭汽车的价格和销量的影响。

a.人们决定多要孩子。

they will want larger vehicles for hauling their kids around, so the demand for minivans will increase. Supply won't be affected. The result is a rise in both price and quantity, as Figure 12 shows.

(类似的词：cost rise/reduce)

d.运动型多用途车（sports utility vehicles, SUVs）价格上升。sport utility vehicles are substitutes for minivans

6.使用供给和需求图，说明下列事件对运动衫市场的影响。

c.所有大学要求学生穿着校服参加早操。

raises the demand for sweatshirt

7.一项调查显示年青人吸实毒品的数量增加了。在随后的辩论中，人们提出了两个假说：

●警察怠工使得人们在街上很容易买到毒品。

●对毒品危害宣传不够使得人们对吸毒的危害性的认识程度下降。

a.使用供给和需求图说明分说明上述每个假说如何导致了吸毒量增加。

b.价格变动信息如何能帮助我们辨这两种假说谁对谁错？

警力的削减将导致毒品的供给增加，如图4-21所示，毒品的供给曲线将从1S向右移动至2S，而需求

不受影响。因此，毒品的均衡价格将下降，均衡数量将增加，即毒品消费量将增加。

育投入的削减将导致毒品需求增加，如图4-22所示，毒品的需求曲线将从1D向右移动至2D，而供给

不受影响。因而毒品的均衡价格将上升，均衡数量将增加，即毒品消费量将增加。

B. 如果毒品均衡价格下降，则该信息支持第一种假设；如果毒品均衡价格上升，则该信息支持第二种

假设

9.番茄酱是一种调味品，也是热狗的互补品。如果热狗价格上升，番茄酱市场将会发生什么样的变化？番茄、番茄汁和桔子汁这三个市场分会发生什么样的变化？

Since the quantity of ketchup falls, the demand for tomatoes by ketchup producers falls, so both price and quantity of tomatoes fall. When the price of tomatoes falls, producers of tomato juice face lower input prices, so the supply curve for tomato juice shifts out, causing the price of tomato juice to fall and the quantity

of tomato juice to rise.

The fall in the price of tomato juice causes people to substitute tomato juice for orange juice, so the demand for orange juice declines, causing the price and quantity of orange juice to fall. Now you can see clearly why a rise in the price of hot dogs leads to a fall in price of orange juice!

10.比萨饼市场上的需求和供给表如下：

a.画出比萨饼的需求曲线和供给曲线。这个市场的均衡价格和均衡数量分为多少？

b.如果市场的实际价格高于均衡价格，什么力量将会驱使市场向均衡状态运动？

c.如果市场的实际价格低于均衡价格，什么力量将会驱使市场向均衡状态运动？

If price were greater than $6, quantity supplied would exceed quantity demanded, so suppliers would reduce their price to gain sales.

If price were less than $6, quantity demanded would exceed quantity supplied, so suppliers could raise their price without losing sales.

In both cases, the price would continue to adjust until it reached $6, the only price at which there is neither a surplus nor a shortage.

11.考虑下列事件：科学家发现吃桔子可以降低患上糖尿病的风险，与此同时，农民使用化肥增加了桔

子树的产量。画图说明这些变化对桔子均衡价格和均衡数量的影响。

12.人们经常将硬面包圈（bagels）和奶油奶酪放在一起吃，因此它们是互补品。

面粉flour—an ingredient in bagels milk——cream cheese的原材料

13. 供给给定the supply curve is vertical because the basketball arena has a fixed number of seats no matter what the price.

a monopolistically competitive market.垄断竞争市场

Each competitor sells a product that may taste differently or may come in a different variety of flavors.

A perfectly competitive market is a market where there are many buyers and sellers of an identical product. No buyer or seller has the ability to influence the price of the product.

Unit5

1.对于下列每组商品，判断哪种商品的需求可能更富有弹性，并说明理由。

a. 教师指定的教材或推理小说mystery novels have close substitutes and are a luxury good, while

c.未来六个月内乘坐地铁或未来五年内乘坐地铁subway rides during the next five years has more elastic demand

d.麦根可乐（root beer）或水

Root beer is a luxury with close substitutes, while water is a necessity withno close substitutes.

2.假设商务乘客和旅游乘客对机票（纽约至波士顿）的需求如下：

用中点法分计算需求弹性

b.为何旅游乘客的弹性可能与商务乘客的弹性不同？

The price elasticity of demand for vacationers is higher

vacationers can choose more easily a different mode of transportation (like driving or taking the train). Business travelers are less likely to do so since time is more important to them and their schedules are less adaptable

3.假设取暖用油的需求价格弹性在短期为0.2，在长期为0.7。

a.如果价格从每单位1.80 元上涨为2.20 元，短期中取暖用油的需求有何变化？（请使用中点法计算。）

b.为什么这个弹性可能取决于时间维度？

With time going by,people can purchase alternative heat sources. They can have more elastic demand in heating oil in the long run.

4.某商品价格变动使得其需求量下降了30%，而该商品的销售总收入上升了15%。该商品的需求曲线是富有弹性的还是缺乏弹性的？请解释。

If quantity demanded fell, price must have risen. If total revenue rose, then the percentage increase in the price must be greater than the percentage decline in quantity demanded. Therefore, demand is inelastic.

5.上个月，咖啡杯的均衡价格陡然上升，但是均衡数量还和以前一样。有三个人试图解释这种现象。谁的解释可能是正确的。请给出理由。

比尔：需求增加，但是供给完全缺乏弹性。

瓦莱丽：供给下降，但需求完全缺乏弹性。

If demand increases, but supply is “totally” inelastic, equilibrium price will rise but the equilibrium quantity will remain the same. This would also occur if supply decreases and demand is “totally” inelastic.

7.对于商品X 和Y，你有下列信息：

●商品X 的需求收入弹性：-3.

●商品X 的需求关于商品Y 价格的交叉价格弹性：2.

收入增加且商品Y 价格下降会必然导致商品X 的需求减少吗？为什么？

Yes, an increase in income would decrease the demand for good X because the income elasticity is less than zero, indicating that good X is an inferior good. A decrease in the price of good Y will

decrease the demand for good X because the two goods are substitutes (as indicated by a cross-

price elasticity that is greater than zero).

8.玛利亚决定总是将她收入的1/3 用于购买衣服。

a.她对衣服的需求收入弹性为多少？1

maintaining her clothing expenditures as a constant fraction of her income means the percentage change in her quantity of clothing must equal her percentage change in income.

b.她对衣服的需求价格弹性为多少？1

every percentage point increase in the price of clothing would lead her to reduce her quantity purchased by the same percentage.

c.如果玛利亚的品味（tastes）变化了，她决定总是将收入的1/4 用于购买衣服，她的需求曲线将怎样变化？她的需求收入弹性和需求价格弹性现在分为多少？

Since Emily spends a smaller proportion of her income on clothing, then for any given price, her quantity demanded will be lower. Thus her demand curve has shifted to the left. But because she'll again spend a constant fraction of her income on clothing, her income and price elasticities of demand remain one.

9.《纽约时报》（1996 年2 月17 日）的报道指出，乘坐地铁的人数在票价上升后减少了：“1995 年12 月份是票价从1.25 美元上升为1.50 美元的第一个完整月份，这个月份乘坐地铁的人比去年同期减少了400 万人次，减少了4.3%。”

a.使用这些数据计算地铁需求的价格弹性。(点弹性，没用中点法the midpoint method)

b.根据你的估算，说说在票价上升后，地铁部门的收入有何变化？

With inelastic demand, the Transit Authority's revenue rises when the fare rises.

c.为什么你计算出来的弹性可能是不可靠的？

it is only the first month after the fare increase.

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.

10. 汤姆和杰瑞一人开一辆车到加油站加油。还没看到价格，每个人都已下了订单。汤姆说，“我要10 加仑汽油。”杰瑞说，“我要10 美元的汽油。”他们的需求价格弹性分为多少？

Tom'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.

11.考虑针对吸烟的公共政策。

年青人对香烟需求的价格弹性大于成年人的。为什么这个结论可能是正确的？

have less income, a higher price elasticity of demand.

adults are more likely to be addicted to cigarettes, making it more difficult to reduce their quantity

demanded in response to a higher price.

12.你是某个博物馆的馆长。博物馆资金不足，因此你决定增加门票收入。你应该提高还是降低门票的价格？为什么？

you need to know if the demand is elastic or inelastic. If demand is elastic, a decline in the price of admissions will increase total revenue. If demand is inelastic, an increase in the price of admissions

will cause total revenue to rise.

13.药品的需求通常缺乏弹性，计算机的需求通常富有弹性。假设技术进步使得这两种商品的供给都变

为原来的2 倍（也就是说，每个价格水平上的供给量都是原来的2 倍）。

a.药品市场和计算机市场的均衡价格和数量将会发生什么样的变化？价格下降，数量增加

b.哪种商品的价格变化大？

c.哪种商品的数量变化大？

d.消费者在这两种商品上花费的费用分别有什么样的变化？

a. As Figure 2 shows, the increase in supply reduces the equilibrium price and increases the

equilibrium quantity in both markets.

b. In the market for pharmaceutical drugs (with inelastic demand), the increase in supply leads to

a relatively large decline in the equilibrium price and a small increase in the equilibrium

quantity.

Figure 2

c. In the market for computers (with elastic demand), the increase in supply leads to a relatively

large increase in the equilibrium quantity and a small decline in the equilibrium price.

d. Because demand is inelastic in the market for pharmaceutical drugs, the percentage increase in

quantity will be lower than the percentage decrease in price; thus, total consumer spending will

decline. Because 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.

14.几年前，密苏里河与密西西比河的洪水摧毁了附近成千上万亩小麦。

a.小麦被摧毁的农民们的状况变差了，但是小麦未被摧毁的农民们却从洪水中受益。为什么？

b.为了确定农民这一群体的状况因洪水变好还是变差了，你需要关于小麦市场的哪些信息？

the destruction of some of the crops reduced the supply, causing the equilibrium price to rise.

b. the price elasticity of demand. It could be that the total revenue received by all farmers as a group actually rose. If the demand is inelasti

c.

15. 解释下列论断为何可能是正确的：全世界发生干旱能提高农民们销售谷物所得的总收入，但如果

只是美国堪萨斯州发生了干旱，那么堪萨斯州的农民的总收入就会减少。

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.

amount), while the output by Kansas farmers declines, thus reducing their income.

Unit6

1.古典音乐的发烧友劝服政府对音乐会门票价格设置了40 元的价格上限，结果去听音乐会的人变

多了还是变少了？

If the price ceiling of $40 per ticket is below the equilibrium price, then quantity demanded exceeds

quantity supplied, so there will be a shortage of tickets. The policy decreases the number of people who attend classical music concerts, because the quantity supplied is lower because of the lower price.

2.政府认为自由市场的奶酪价格太低了。

a.假设政府对奶酪市场设置了紧的价格下限。画图分析它对奶酪价格和销售量的影响。奶酪出现了短缺

还是过剩现象？

b.生产奶酪的农民抱怨价格下限降低了他们的总收入。这事有可能吗？请解释。

c.政府对农民抱怨的反应是，同意以价格下限的价格水平购买所有过剩的奶酪。与原来只实行价格下限

政策相比，谁从这个新政策中获益？谁遭受了损失？

producers benefit and taxpayers lose.

Producers would produce quantity Q3 of cheese, and their total revenue would increase substantially.

However, consumers would buy only quantity Q2 of cheese, so they are in the same position as before.

Taxpayers lose because they would be financing the purchase of the surplus cheese through higher taxes.

3.一项最新研究发现，游戏飞盘的需求和供给表为：8

飞盘制造者对政府宣称，飞盘提高了科学家对空气动力学的理解程度，因此对国家安全非常重要。国会表决

同意对飞盘实行2 元的价格下限，该价格下限高于均衡价格。新的市场价格是多少？飞盘的销量是多少？

10 the quantity demanded.

c.愤怒的大学生在华盛顿游行，要求政府降低飞盘的价格。国会因此取消了价格下限并设置了价格上限，该价格上限比原来的价格下降低1 元钱。新的市场价格是多少？飞盘的销量是多少？9 it has no effect, because the market equilibrium price is $8, which is below the ceiling. So the market price is $8 and the quantity sold is six million Frisbees.

4.假设美国联邦政府要求消费者每买一箱啤酒就要缴纳2 元的税收。（事实上，联邦政府和州政府都

征收某种形式的啤酒税。）

b.现在画出征税后市场的供给和需求图，在图中标示出消费者支付的价格、生产者得到的价格以及啤酒

的销量。消费者支付的价格和生产者得到的价格之差是多少？啤酒的销量是增加了还是减少了？

5.某参议员希望增加税收并且使得企业职工状况变好。他的助手建议说：既然工资税由企业缴纳一部分、职工缴纳一部分，只要提高企业缴纳的那部分工资税、降低职工缴纳的那部分工资税，而且做到企业多缴的部分足够补偿职工少缴纳的部分，那么就能实现你的目标。

这个助手的建议正确吗？为什么？

Wrong.

It would not make workers better off, because the division of the burden of a tax depends on the elasticity of supply and demand and not on who must pay the tax. The less elastic ,the more burden.

Because the tax wedge would be larger, it is likely that both firms and workers, who share the burden of any tax, would be worse off.

(the more elastic the more tax)

6.如果政府对每辆高档汽车征收500 元的奢侈品税，征税后价格会上升。站在消费者的角度来看，该

汽车的价格上涨幅度是大于、小于还是恰好等于500 元？

a luxury car likely has an elastic demand, the price will rise by less than $500. The burden of any tax is shared by both producers and consumers

(非答案，也可写上)

The only exceptions would be if the supply curve were perfectly elastic or the demand curve were perfectly inelastic, in which case consumers would bear the full burden of the tax and the price paid by consumers would rise by exactly $500.

7.美国国会和总统都认为美国应该减少汽油使用量，从而减少空气污染。他们对市场上出售的汽油征税，每单位汽油征收0.50 元。

a.他们应该对汽油的生产者（即供给者）征税还是对汽油的消费者征税？使用供给和需求图详细解释。

It does not matter whether the tax is imposed on producers or consumers the effect will be the same

If the tax is imposed on producers, the supply curve shifts up by the amount of the tax (50 cents) to S2. Then the equilibrium quantity is Q2, the price paid by consumers is P2, and the price received (after taxes are paid) by producers is P2 – 50 cents.

If the tax is instead imposed on consumers, the demand curve shifts down by the amount of the tax (50 cents)

to D2. The downward shift in the demand curve (when the tax is imposed on consumers) is exactly the same magnitude as the upward shift in the supply curve when the tax is imposed on producers. So again, the equilibrium quantity is Q2, the price paid by consumers is P2 (including the tax paid to the government), and the price received by producers is P2 – 50 cents.

b.如果汽油的需求弹性增大，那么征税对于减少汽油消费量的效果增加了还是减少了？请用文字和图形

进行解释。

The more elastic the demand curve is, the more effective this tax will be

Greater elasticity of demand means that quantity falls more in response to the rise in the price of gasoline.

e.征税使得汽油消费者的状况变好了还是变差了？为什么？

hurt by the tax because they get less gasoline at a higher price.

d.征税使得石油行业职工的状况变好了还是变差了？为什么？

Hurt..

With a lower quantity of gasoline being produced, some workers may lose their jobs. With a lower price received by producers, wages of workers might decline.

8.教材中有个案例探讨的是美国联邦最低工资法。

a.假设在非熟练劳动市场上，最低工资高于均衡工资。画出非熟练劳动市场的供给和需求图。使用非熟

练劳动的供给和需求图，表明市场工资、就业人数、失业人数。另外，请在图中指出支付给非熟练工人的总工资。

In the absence of the minimum wage, the market wage would be w1 and Q1 workers would be employed.

With the minimum wage (wm) imposed above w1, the market wage is wm, the number of employed workers is Q2, and the number of workers who are unemployed is Q3 ? Q2. Total wage payments to workers are shown as the area of rectangle ABCD, which equals wm times Q2.

b.现在假设劳工部长提议提高最低工资。这种政策对就业人数有何影响？就业人数的变化取决于需求弹

性还是供给弹性、还是取决于二者亦或不取决于这二者？

depends only on the elasticity of demand. The elasticity of supply does not matter, because there is a surplus

of labor.

c.上述（b）中的政策对失业人数有何影响？失业人数的变化取决于需求弹性还是供给弹性、还是取决

于二者亦或不取决于这二者？

increase unemployment.

depends on both the elasticities of supply and demand. The elasticity of demand determines the change in the quantity of labor demanded, the elasticity of supply determines the change in the quantity of labor supplied, and the difference between the quantities supplied and demanded of labor is the amount of unemployment.

b）中的政策增加还是减少了支付给非熟练工人的总工资？如果非熟练劳动的需求是富有弹性的，该问题的答案(

With inelastic demand, the percentage decline in employment would be lower than the percentage increase in the wage, so total wage payments increase.

9.美国政府实施了两种干预香烟市场的项目。一是，媒体宣传和在烟盒上印制警示语，目的在于让公众意识到香烟的危害。二是，农业部对烟农进行价格扶持，即将烟草的价格提高到均衡价格上方。

a. 这两个项目对香烟的消费有何影响？使用香烟市场图说明你的答案。

b. 这两个项目对香烟价格有何综合影响？

The combined effect of the two programs on the price of cigarettes is ambiguous. The education

the cost of production of cigarettes, which tends to increase the price. The end result on price depends on the relative sizes of these two effects.

further reduces cigarette consumption, because it increases the price to consumers. As shown in the figure, the quantity falls to Q3.

10.红袜队主场所在的芬威球场，最多可坐39,000 人。因此，供给的门票数量固定在这一数字上。波士顿市发现了增加财政收入的良机：消费者每买一张门票需要缴纳5 元税收。红袜队的球迷都是热爱公益的市民，他们乖乖地缴税。画图说明税收的影响（准确标出相关数据）。税收负担落在球队老板、球迷还是二者身上？

Since the supply of seats is perfectly inelastic, the entire burden of the tax will fall on the team’s owners.

Ok~11.补贴和税收相反。对冰淇淋买者征税时，消费者每买一个冰淇淋需要缴纳0.50 元的税收；而在补贴的情形下，消费者每买一个冰淇淋政府就给他0.50 元。

a.每个冰淇淋补贴0.50 元的政策，对冰淇淋的需求曲线、买者实际支付的价格、卖者实际得到的价格和冰淇淋的销量分有何影响？

b.这个补贴政策使消费者受益还是遭受损失？生产者呢？政府呢？

12. 2008 年春天，参议员约翰.麦肯恩和希拉里.克林顿（那时他们在竞选总统）提出暂时取消联邦汽油税，该政策只在2008 年夏季有效，目的是帮助消费者应对较高的汽油价格。

a.在夏天，由于正值度假高峰，汽油需求旺盛，炼油厂几乎满负荷运行。这个事实说明汽油的供给价格弹性是怎样的？inelastic.

b.根据你在（a）中的答案，你认为谁将会从这个暂时性的政策中受益？

If gasoline refineries are operating at near full capacity, supply is likely to be highly inelastic.

b. The burden of a tax falls on the side of the market that is relatively more inelasti

c. Thus, it will be suppliers who will benefit from the temporary suspension of the federal gasoline tax.

Unit7

1.梅丽莎花了120 元钱买了一个iPod，并因此得到80 元钱的消费者剩余。

a.她的支付意愿为多少？200

b.如果她买的iPod 是打折品，因此她只花了90 元钱，这种情形下她的消费者剩余为多少？

c.如果iPod 的价格为250 元，她的消费者剩余为多少？

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.

什么样的变化。说明柠檬汽水市场上的消费者剩余将会出现什么的样的变化。请借助图形说明。

Note that an event that affects consumer surplus in one market often has effects on consumer surplus in other markets.

3.假设法式面包（French bread）的需求增加。说明法式面包市场中的生产者剩余的变化。说明面粉市场中的生产者剩余的变化。请借助图形说明。

Note that an event that affects producer surplus in one market leads to effects on producer surplus in related markets.

7.在过去二十年间，平面电视的生产成本已经下降了。请使用这个事实分析下列各个问题。c.假设平面电视的供给非常具有弹性。谁从生产成本下降中获益更大——是消费者还是生产者？

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.

8.四个消费者对理发的支付意愿分如下：

杰瑞：7 元；奥普拉：2 元；艾伦：8 元；菲尔：5 元

四家理发店的生产成本分如下：

A：3 元；B: 6 元；C：4 元；D：2 元。

每个理发店只能为一个人理发。站在效率角度上，应该给几个人理发？哪个理发店应该理发、哪个消费者应

该理发？可能的最大总剩余为多少？

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).

9.假设技术进步降低了计算机的生产成本。 b.计算机和打字机是替代品。使用供给和需求图说明打字机市

场中的价格变化、交易

量变化、消费者剩余的变化和生产者剩余的变化。打字机的生产者应该为计算机的生产技术进步感到高兴还

是难过？

Typewriter producers are sad because their producer surplus declines.

d.上述分析是否有助于解释为何软件生产商比尔.盖茨成为世界富豪之一吗？

YES, because his company produces a lot of software that is a complement with computers and there has been tremendous technological advance in computers.

10.你的朋友正在考虑使用哪家手机运营商的服务。运营商A 每个月索要120 元的服务费，但不限制通

话时间。运营商B 不收取固定的服务费，但规定每分钟话费为1 元。你朋友每个月的通话时间需求为

QD=150-50P，其中P 是每分钟通话的费用。

a.你的朋友若使用运营商A，他额外通话一分钟的成本为多少？若使用运营商B 呢？With Provider A, the cost of an extra minute is $0. With Provider B, the cost of an extra minute is $1.

b.根据你在（a）中的答案，说明若使用运营商A，你朋友应该通话几分钟？若使用运营商B 呢？

With Provider A, my friend will purchase 150 minutes [= 150 – (50)(0)]. With Provider B, my friend would purchase 100 minutes [= 150 – (50)(1)].

c.若你朋友使用运营商A，他每个月应缴纳多少钱？若使用运营商B 呢？

With Provider A, he would pay $120. The cost would be $100 with Provider B.

d若使用运营商A，他的消费者剩余为多少？若使用运营商B 呢？（提示：画出需求曲线并回顾消费者剩余的几何计算方法。）

e.你会建议你朋友使用哪个运营商？为什么？

With Provider A, he buys 150 minutes and his consumer surplus is equal to (1/2)(3)(150) – 120 = 105. With Provider B, his consumer surplus is equal to (1/2)(2)(100) = 100.

e. I would recommend Provider A because he receives greater consumer surplus.

11.考虑医疗保险对医疗服务提供量的影响。假设典型的医疗服务的成本为100 元，但一个拥有医疗保险的

人只需要自己支付20 元，他的保险公司支付剩下的80 元。（保险公司支付的钱来自它收取的保费，但

是被保险人支付的保险费和他接受的医疗服务量无关。） a.画出医疗服务市场的需求曲线。（在你的图中，横轴应该表示医疗服务的数量。）如果每单位医疗服务的价格为100 元，标示出医疗服务需求量。b.如果消费者对于每单位医疗服务只支付20 元，在你的图中标示出医疗服务的需求量。如果每单位医疗

服务的成本为100 元，并且如果每个人都有刚才所说的医疗保险，那么医生提供的医疗服务数量能使总剩余最大吗？请解释。 c.经济学家通常认为医疗保险制度使得人们过度使用医疗服务。为何会出现这种现象，请给出分析。 d.什么样的政策能够阻止这种过度使用的现象？

Figure 18 illustrates the demand for medical care. If each procedure has a price of $100, quantity demanded

will be Q1 procedures.

Figure 18

b. 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.

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.

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.

Unit8

1.比萨饼的市场具有向下倾斜的需求曲线和向上倾斜的供给曲线。

a.画出竞争市场均衡。标示出价格、交易量、消费者剩余和生产者剩余。

b.假设政府规定每个比萨饼店每卖出一个比萨饼都要缴纳1 元钱的税收。画图说明这种税对比萨饼市场的影响，你要标示出消费者剩余、生产者剩余、政府税收收入和净损失。与征税前相比，它们分有什么变化？

c.如果停止征税，比萨饼的买者和卖者的状况都会变好，但是政府就丧失了税收收入。

假设消费者和生产者资源转移部分收益给政府。与征税的情形相比，这三方的状况都能变好吗？在你的图中用阴影区域进行说明。

without the tax，If consumers and producers gave a little bit more than B+D to the government, then all three parties, including the government, would be better off. This illustrates the inefficiency of taxation

2.评价下列两个论断。你认为正确吗？为什么？

a.“没有净损失的某种税收无法为政府筹集到任何收入。”

F

An example is the case of a tax when either supply or demand is perfectly inelastic. The tax has neither an effect on quantity nor any deadweight loss, but it does raise revenue.

b.“为政府未筹集到任何收入的某种税收不会造成任何净损失。”

F

An example is the case of a 100 percent tax imposed on sellers. With a 100 percent tax on their sales of the good, sellers won't supply any of the good, so the tax will raise no revenue. Yet the tax has a large deadweight loss, since it reduces the quantity sold to zero.

4.假设政府对取暖用油征税。

a.征税后第一年造成的净损失可能比征税后第五年造成的净损失大吗？(不可能)为什么？

over time they may switch to other energy sources and people buying new heaters for their homes will more likely choose gas or electric, so the tax will have a greater impact on quantity

b.征收后第一年筹集到的税收收入可能比征税后第五年筹集的税收收入大吗？为什么？（可能）

Inthe first year, demand is more inelastic, so the quantity does not decline as much and tax revenue is relatively high. As time passes and more people substitute away from oil, the equilibrium quantity declines, as does tax revenue.

5.有一天上完经济学课程后，你的朋友说政府应该对食品征税，这是筹集收入的一种好方法，因为食品的需求通常是非常缺乏弹性的。在什么意义上，对食品征税是筹集收入的“好”方法？在什么意义上，它不是筹集收入的“好”方法？

a good way to raise revenue because it does not lead to much of a deadweight loss; thus taxing food is less inefficient than taxing other things.

But it is not a good way to raise revenue from an equity point of view, since poorer people spend a higher proportion of their income on food, so the tax would hit them harder than it would hit wealthier people.

6. 来自纽约的已故参议员丹尼尔.帕特里克.莫伊尼汉（Daniel Patrick Moynihan）曾经提出应对空头弹（hollow-tipped bullets）征收10,000%的税（一）。

a.你认为这种税能够筹集很多收入吗？为什么？

such a high rate that it is not likely to raise much revenue. Because of the high tax rate, the equilibrium quantity in the market is likely to be at or near zero.

b.如果这种税筹集不到收入，为何该参议员还要提出这样的建议？

ban the use of hollow-tipped bullets. In this case, a tax is as effective as an outright ban.

7.政府对购买袜子的行为征税。

b.生产者得到的价格上升还是下降了？你能判断出生产者的总收入增加了还是下降了吗？请解释。Unless supply is perfectly elastic, the price received by producers falls

c.消费者支付的价格上升还是下降了？你能判断出消费者的总支出增加了还是下降了吗？请详细解释。（提示：考虑弹性。）如果消费者总支出下降，那么消费者剩余增加了吗？请解释。(不管支出增加Or减少，CS都减少了) because of the increase in price and reduction in quantity.

8.假设政府当前对小装饰物（widgets）征收1 分钱的税，筹集到的税收收入为1 亿元；政府对小玩具（gadgets）征收10 分钱的税，筹集到的税收收入也为1 亿元。如果政府对小装饰物的征税税率变为原来的2 倍，但取消对小玩具征税，那么政府筹集到的收入是增加了、减少了还是不变？请解释。

The tax revenue from the tax on widgets equals the tax per unit times the quantity produced. Assuming that neither the supply nor the demand curves for widgets are perfectly elastic or inelastic and since the increased tax causes a smaller quantity of widgets to be produced, then it is impossible for tax revenue to double--multiplying the tax per unit (which doubles) times the quantity (which declines) gives a number that is less than double the original tax revenue from widgets. So the government's tax change will yield less money than before.

（与上文无关）

From the standpoint of economic efficiency, the British poll tax is wonderful, because it does not distort any economic incentives, so it has no deadweight loss. But such a tax is inequitable, because it is more burdensome on the poor than on the rich. As a result, the tax was quite unpopular.

9.补贴会造成了净损失

10.思茅镇（Smalltown）宾馆房间的价格为每间每天100 元，通常一天能租出去1,000 间。

a.为了筹集收入，镇长决定宾馆每租出去一个房间就要缴纳10 元钱的税。征税后，房间价格变为108 元，租出去的房间数量减少为900 间。计算这种税筹集到的收入和它造成的净损失。

（提示：三角形的面积=1/2×底×高。）

b.现在镇长将税率增加为原来的2 倍即20 元。房间价格上升为116 元，租出去的房间数量下降为800 间。计算税收收入和净损失。它们分是原来的2 倍吗？请解释。

Unit10

1.考虑下列两种防止你的汽车被盗的方法：使用方向盘锁，小偷难以偷走你的车；使用追踪系统，警察可以

容易地抓到盗车贼。哪种方法对其他车主具有负的外部性？哪种有正的外部性？根据你的分析提出政策建议。

2.你赞成下列说法吗，为什么？

a.“使用矫正税减少污染时，必须综合权衡征税得到的收益和征税造成的净损失。”

b.“政府在决定是对消费者还是生产者征收矫正税时，它应该对产生外部性的那一方征税。”

3.考虑灭火器市场。

a.为什么灭火器可能具有正的外部性？

b.画出灭火器的市场图，在图形中标记出需求曲线、社会价值曲线、供给曲线和社会成本曲线。

c.指出市场均衡数量和有效率的数量。从直觉上解释为什么这两个数量不同。

d.如果每个灭火器产生的外部收益为10 元，说出一种能产生有效率结果的公共政策。

4.旧金山一家戏剧公司提议在市区建立一座新的剧院。在批准之前，城市规划者研究了新剧院对周边社区的

影响。

a.研究发现，剧院会吸引车流、造成交通拥挤，这对社区不利。据估计，剧院每卖一张票就会对社区造

成5 元的额外交通成本。这是哪一种外部性？为什么？

b.画出剧院门票的市场图，标记出需求曲线、社会价值曲线、供给曲线、社会成本曲线、均衡数量、有

效率的数量。你还要在图中表明每张门票的外部成本是多少元钱。

c.进一步研究发现，剧院还将产生第二种外部性。戏剧排练通常持续到深夜，演员、舞台人员和其他剧

院工作者在不同时间往来穿梭。城市规划者发现，行人增加提高了周围街道的安全性，据估计剧院每卖一张

门票能对该社区产生2 元的收益。这是哪一种外部性，为什么？

d.由于剧院现在已有两种外部性，请再画一个图，说明该情形下的剧院门票的市场。仍然需要在图中标

记出需求曲线、社会价值曲线、供给曲线、社会成本曲线、市场均衡数量、有效率的数量。你还要在图中表

明每张门票产生的两种外部性的大小。

e.说出一种能达到有效率数量的政府政策。

6.很多观察家认为我们社会的污染水平太高了。

a.如果社会想将总污染水平降低一定数量，那么让不同企业减少不同数量的污染为何是有效率的？

b.命令和管制方法通常责令所有企业减少相等的污染量。为什么这样的方法通常不能让污染大户更多地

降低污染？

c.经济学家认为合适的矫正税或可交易的污染权能导致有效率的污染减少量。为什么这样的方法能让污

染大户有动机降低污染？

7. 胡威尔（Whoville）市的很多居民都喜欢喝一种叫做滋乐普（Zlurp）的饮料。假设这些居民是相同的。

每个居民对这种可口饮料的支付意愿如下：

a.该饮料的生产成本为1.50 元，完全竞争的供给者以成本价出售（供给曲线是水平的）。该市的每个

居民将消费多少瓶饮料？每个人的消费者剩余为多大？

b.生产饮料产生了污染。每瓶饮料的外部成本为1 元。如果考虑该外部成本，在（a）中分析的那个配

置处，每个人的总剩余为多大？

c.露.辛迪（Cindy Lou）是该市的一个居民，她决定自己减少饮料的消费量，减少一瓶。辛迪的福利有何变化（她的消费者剩余减去她经历的污染成本）？辛迪的决策对该市所有居民的总剩余有何影响？

d.市长格林奇（Grinch）对每瓶饮料征收1 元钱的税收。现在每个人的消费量为多少？计算消费者剩余、外部成本、政府收入和每个人的总剩余。

e.根据你的计算结果，你会支持市长的政策吗？为什么？

8. 瑞格（Ringo）喜欢大声播放摇滚乐，鲁奇阿诺（Luciano）喜欢歌剧、痛恨摇滚乐。不幸的是他们是邻居，而公寓墙壁薄如纸。

a.此处的外部性是什么？

b.房东可以实行什么样的命令和管制措施？这样的措施能导致无效率的结果吗？

c.假设房东允许他们想干什么就干什么。根据科斯定理，瑞格和鲁奇阿诺如何才能达到有效率的结果？

哪些因素能阻止他们达到这样的结果？

9.图4 表明，对于任何给定的关于污染权的需求曲线，政府的下列两种做法可以达到同样的结果：一是用

矫正税制定污染权的价格；二是用污染许可制定污染数量。假设社会在污染控制技术上取得明显进展。

a.仿照图4 画图说明该技术进展对污染权需求的影响。

b.分析在上述每种管制体系下，该技术进展对污染的价格和数量的影响。

10.假设政府决定分配既定数量的可交易污染许可。