曼昆经济学原理微观经济学英文版
课后习题答案（考试章节筛选）
UNIT 1
SOLUTIONS TO TEXT PROBLEMS:
Quick Quizzes
1. The four principles of economic decisionmaking are: (1) people face tradeoffs;
(2) the cost of something is what you give up to get it; (3) rational people
think at the margin; and (4) people respond to incentives. People face
tradeoffs because to get one thing that they like, they usually have to give up another thing that they like. The cost of something is what you give up to get it, not just in terms of monetary costs but all opportunity costs.
Rational people think at the margin by taking an action if and only if the
marginal benefits exceed the marginal costs. People respond to incentives
because as they compare benefits to costs, a change in incentives may cause their behavior to change.
2. The three principles concerning economic interactions are: (1) trade can make
everyone better off; (2) markets are usually a good way to organize economic activity; and (3) governments can sometimes improve market outcomes. Trade can make everyone better off because it allows countries to specialize in what they do best and to enjoy a wider variety of goods and services. Markets are usually a good way to organize economic activity because the invisible hand leads markets to desirable outcomes. Governments can sometimes improve market outcomes because sometimes markets fail to allocate resources efficiently
because of an externality or market power.
3. The three principles that describe how the economy as a whole works are: (1)
a country’s standard of living depends on its ability to produce goods and
services; (2) prices rise when the government prints too much money; and (3) society faces a short-run tradeoff between inflation and unemployment. A
country’s standard of livi ng depends on its ability to produce goods and
services, which in turn depends on its productivity, which is a function of the education of workers and the access workers have to the necessary tools and technology. Prices rise when the government prints too much money because more money in circulation reduces the value of money, causing inflation.
Society faces a short-run tradeoff between inflation and unemployment that is only temporary and policymakers have some ability to exploit this relationship using various policy instruments.
Questions for Review
1. Examples of tradeoffs include time tradeoffs (such as studying one subject over
another, or studying at all compared to engaging in social activities) and
spending tradeoffs (such as whether to use your last ten dollars on pizza or
on a study guide for that tough economics course).
2. The opportunity cost of seeing a movie includes the monetary cost of admission
plus the time cost of going to the theater and attending the show. The time cost depends on what else you might do with that time; if it's staying home and watching TV, the time cost may be small, but if it's working an extra three hours at your job, the time cost is the money you could have earned.
3. The marginal benefit of a glass of water depends on your circumstances. If
you've just run a marathon, or you've been walking in the desert sun for three hours, the marginal benefit is very high. But if you've been drinking a lot of liquids recently, the marginal benefit is quite low. The point is that even the necessities of life, like water, don't always have large marginal benefits.
4. Policymakers need to think about incentives so they can understand how people
will respond to the policies they put in place. The text's example of seat belts shows that policy actions can have quite unintended consequences. If incentives matter a lot, they may lead to a very different type of policy; for example, some economists have suggested putting knives in steering columns so that people will drive much more carefully! While this suggestion is silly, it highlights the importance of incentives.
5. Trade among countries isn't a game with some losers and some winners because
trade can make everyone better off. By allowing specialization, trade between people and trade between countries can improve everyone's welfare.
6. The "invisible hand" of the marketplace represents the idea that even though
individuals and firms are all acting in their own self-interest, prices and the marketplace guide them to do what is good for society as a whole.
7. The two main causes of market failure are externalities and market power. An
externality is the impact of one person’s actions on the well-being of a
bystander, such as from pollution or the creation of knowledge. Market power refers to the ability of a single person (or small group of people) to unduly influence market prices, such as in a town with only one well or only one cable television company. In addition, a market economy also leads to an unequal distribution of income.
8. Productivity is important because a country's standard of living depends on
its ability to produce goods and services. The greater a country's
productivity (the amount of goods and services produced from each hour of a worker's time), the greater will be its standard of living.
9. Inflation is an increase in the overall level of prices in the economy.
Inflation is caused by increases in the quantity of a nation's money.
10. Inflation and unemployment are negatively related in the short run. Reducing
inflation entails costs to society in the form of higher unemployment in the
short run.
Problems and Applications
1. a. A family deciding whether to buy a new car faces a tradeoff between
the cost of the car and other things they might want to buy. For example,
buying the car might mean they must give up going on vacation for the
next two years. So the real cost of the car is the family's opportunity
cost in terms of what they must give up.
b. For a member of Congress deciding whether to increase spending on
national parks, the tradeoff is between parks and other spending items
or tax cuts. If more money goes into the park system, that may mean
less spending on national defense or on the police force. Or, instead
of spending more money on the park system, taxes could be reduced.
c. When a company president decides whether to open a new factory, the
decision is based on whether the new factory will increase the firm's
profits compared to other alternatives. For example, the company
could upgrade existing equipment or expand existing factories. The
bottom line is: Which method of expanding production will increase
profit the most?
d. In deciding how much to prepare for class, a professor faces a tradeoff
between the value of improving the quality of the lecture compared to
other things she could do with her time, such as working on additional
research.
2. When the benefits of something are psychological, such as going on a vacation,
it isn't easy to compare benefits to costs to determine if it's worth doing.
But there are two ways to think about the benefits. One is to compare the
vacation with what you would do in its place. If you didn't go on vacation,
would you buy something like a new set of golf clubs? Then you can decide if
you'd rather have the new clubs or the vacation. A second way is to think about
how much work you had to do to earn the money to pay for the vacation; then
you can decide if the psychological benefits of the vacation were worth the
psychological cost of working.
3. If you are thinking of going skiing instead of working at your part-time job,
the cost of skiing includes its monetary and time costs, which includes the
opportunity cost of the wages you are giving up by not working. If the choice
is between skiing and going to the library to study, then the cost of skiing
is its monetary and time costs including the cost to you of getting a lower
grade in your course.
4. If you spend $100 now instead of saving it for a year and earning 5 percent interest, you are giving up the opportunity to spend $105 a year from now. The idea that money has a time value is the basis for the field of finance, the subfield of economics that has to do with prices of financial instruments like stocks and bonds.
5. The fact that you've already sunk $5 million isn't relevant to your decision
anymore, since that money is gone. 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.
You are right to think that the project has lost a total of $3 million ($6 million
in costs and only $3 million in revenue) and you shouldn't have started it.
That's true, but if you don't spend the additional $1 million, you won't have
any sales and your losses will be $5 million. So what matters is not the total
profit, but the profit you can earn at the margin. In fact, you'd pay up to
$3 million to complete development; any more than that, and you won't be
increasing profit at the margin.
6. Harry suggests looking at whether productivity would rise or fall.
Productivity is certainly important, since the more productive workers are,
the lower the cost per gallon of potion. Ron wants to look at average cost.
But both Harry and Ron are missing the other side of the equation?revenue.
A firm wants to maximize its profits, so it needs to examine both costs and
revenues. Thus, Hermione is right?it’s best to examine whether the extra
revenue would exceed the extra costs. Hermione is the only one who is thinking
at the margin.
7. a. The provision of Social Security benefits lowers an individual’s
incentive to save for retirement. The benefits provide some level of
income to the individual when he or she retires. This means that the
individual is not entirely dependent on savings to support consumption
through the years in retirement.
b. Since a person gets fewer after-tax Social Security benefits the
greater is his or her earnings, there is an incentive not to work (or
not work as much) after age 65. The more you work, the lower your
after-tax Social Security benefits will be. Thus the taxation of
Social Security benefits discourages work effort after age 65.
8. a. When welfare recipients who are able to work have their benefits cut
off after two years, they have greater incentive to find jobs than if
their benefits were to last forever.
b. The loss of benefits means that 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. Thus the change in the law is one
that increases efficiency but reduces equity.
9. By specializing in each task, you and your roommate can finish the chores more
quickly. If you divided each task equally, it would take you more time to cook
than it would take your roommate, and it would take him more time to clean than
it would take you. By specializing, you reduce the total time spent on chores.
Similarly, countries can specialize and trade, making both better off. For
example, suppose it takes Spanish workers less time to make clothes than French
workers, and French workers can make wine more efficiently than Spanish workers.
Then Spain and France can both benefit if Spanish workers produce all the clothes
and French workers produce all the wine, and they exchange some wine for some
clothes.
10. a. Being a central planner is tough! To produce the right number of CDs
by the right artists and deliver them to the right people requires an
enormous amount of information. You need to know about production
techniques and costs in the CD industry. You need to know each person's
musical tastes and which artists they want to hear. If you make the
wrong decisions, you'll be producing too many CDs by artists that people
don't want to hear, and not enough by others.
b. Your decisions about how many CDs to produce carry over to other
decisions. You have to make the right number of CD players for people
to use. If you make too many CDs and not enough cassette tapes, people
with cassette players will be stuck with CDs they can't play. The
probability of making mistakes is very high. You will also be faced
with tough choices about the music industry compared to other parts
of the economy. If you produce more sports equipment, you'll have
fewer resources for making CDs. So all decisions about the economy
influence your decisions about CD production.
11. a. Efficiency: The market failure comes from the monopoly by the cable
TV firm.
b. Equity
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.
12. a. If everyone were guaranteed the best health care possible, much more
of our nation's output would be devoted to medical care than is now
the case. Would that be efficient? If you think that currently
doctors form a monopoly and restrict health care to keep their incomes
high, you might think efficiency would increase by providing more health care. But more likely, 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, if poor people are less likely to have adequate health care, providing more health care would represent 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. 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. After all, no one plans to be laid off, so
unemployment benefits are a form of insurance. But there’s an
efficiency problem why work if you can get income for doing nothing?
The ec onomy isn’t operating efficiently if people remain unemployed
for a long time, and unemployment benefits encourage unemployment.
Thus, there’s a tradeoff between equity and efficiency. The more
generous are unemployment benefits, the less income is lost by an
unemployed person, but the more that person is encouraged to remain
unemployed. So greater equity reduces efficiency.
13. Since average income in the United States has roughly doubled every 35 years,
we are likely to have a better standard of living than our parents, and a much
better standard of living than our grandparents. This is mainly the result
of increased productivity, so that 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.
14. If Americans save more and it leads to more spending on factories, there will
be an increase in production and productivity, since the same number of workers
will have more equipment to work with. The benefits from higher productivity
will go to both the workers, who will get paid more since they're producing
more, and the factory owners, who will 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.
15. a. If people have more money, they are probably going to spend more on
goods and services.
b. If prices are sticky, and people spend more on goods and services, then
output may increase, as producers increase output to meet the higher
demand rather than raising prices.
c. If prices can adjust, then the higher spending of consumers will be
matched with increased prices and output won't rise.
16. To make an intelligent decision about whether to reduce inflation, a policymaker
would need to know what causes inflation and unemployment, as well as what
determines the tradeoff between them. Any attempt to reduce inflation will likely lead to higher unemployment in the short run. A policymaker thus faces
a tradeoff between the benefits of lower inflation compared to the cost of higher
unemployment.
UNIT2
SOLUTIONS TO TEXT PROBLEMS:
Quick Quizzes
1. Economics is like a science because economists devise theories, collect data,
and analyze the data in an attempt to verify or refute their theories. In other
words, economics is based on the scientific method.
Figure 1 shows the production possibilities frontier for a society that produces food and clothing. Point A is an efficient point (on the frontier), point B is an inefficient point (inside the frontier), and point C is an infeasible point (outside the frontier).
Figure 1
The effects of a drought are shown in Figure 2. The drought reduces the amount of food that can be produced, shifting the production possibilities frontier inward.
Figure 2
Microeconomics is the study of how households and firms make decisions and how
they interact in markets. Macroeconomics is the study of economy-wide
phenomena, including inflation, unemployment, and economic growth.
2. An example of a positive statement is “higher taxes discourage work effort”
(many other answers are possible). That’s a positive statement because it
describes the effects of higher taxes, describing the world as it is. An
example of a normative statement is “the government should reduce tax rates.”
That is a normative statement because it’s a claim about how the world should
be.
Parts of the government that regularly rely on advice from economists are the
Treasury Department in designing tax policy, the Department of Labor in
analyzing data on the employment situation, the Justice Department in enforcing
the nation’s antitrust laws, the Congressional Budget Offic e in evaluating
policy proposals, and the Federal Reserve in analyzing economic developments
(many other answers are possible).
3. Economic advisers to the president might disagree about a question of policy
because of differing scientific judgments or differences in values. Questions for Review
1. Economics is like a science because economists use the scientific method. They
devise theories, collect data, and then analyze these data in an attempt to
verify or refute their theories about how the world works. Economists use
theory and observation like other scientists, but they are limited in their
ability to run controlled experiments. Instead, they must rely on natural
experiments.
2. Economists make assumptions to simplify problems without substantially
affecting the answer. Assumptions can make the world easier to understand.
3. An economic model cannot describe reality exactly because it would be too
complicated to understand. A model is a simplification that allows the
economist to see what is truly important.
4. Figure 3 shows a production possibilities frontier between milk and cookies
(PPF1). If a disease kills half of the economy's cow population, less milk
production is possible, so the PPF shifts inward (PPF2). Note that if the
economy produces all cookies, so it doesn't need any cows, then production is
unaffected. But if the economy produces any milk at all, then there will be
less production possible after the disease hits.
Figure 3
5. The idea of efficiency is that an outcome is efficient if the economy is getting
all it can from the scarce resources it has available. In terms of the
production possibilities frontier, an efficient point is a point on the frontier, such as point A in Figure 4. A point inside the frontier, such as point B,
is inefficient since more of one good could be produced without reducing the
production of another good.
Figure 4
6. The two subfields in economics are microeconomics and macroeconomics.
Microeconomics is the study of how households and firms make decisions and how
they interact in specific markets. Macroeconomics is the study of economy-wide
phenomena.
7. Positive statements are descriptive and make a claim about how the world is,
while normative statements are prescriptive and make a claim about how the world
ought to be. Here is an example. Positive: A rapid growth rate of money is
the cause of inflation. Normative: The government should keep the growth rate
of money low.
8. The Council of Economic Advisers is a group of economists who consult with the
president of the United States about economic matters. The Council consists
of three members and a staff of several dozen economists. It writes the annual
Economic Report of the President.
9. Economists sometimes offer conflicting advice to policymakers for two reasons:
(1) economists may disagree about the validity of alternative positive
theories about how the world works; and (2) economists may have different values
and, therefore, different normative views about what public policy should try
to accomplish.
Problems and Applications
1. Many answers are possible.
2. a. Steel is a fairly uniform commodity, though some firms produce steel
of inferior quality.
b. Novels are each unique, so they are quite distinguishable.
c. Wheat produced by one farmer is completely indistinguishable from wheat
produced by another.
d. Fast food is more distinguishable than steel or wheat, but certainly
not as much as novels.
3. See Figure 5; the four transactions are shown.
Figure 5
4. a. Figure 6 shows a production possibilities frontier between guns and
butter. It is bowed out because when most of the economy’s resources
are being used to produce butter, the frontier is steep and when most
of the economy’s resources are being used to produce gu ns, the frontier
is very flat. 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 production possibilities frontier is flat. 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 production possibilities frontier is steep.
b. Point A is impossible for the economy to achieve; it is outside the
production possibilities frontier. Point B is feasible but
inefficient because it’s inside the production possibilities
frontier.
Figure 6
c. The Hawks might choose a point like H, with many guns and not much butter.
The Doves might choose a point like D, with a lot of butter and few
guns.
d. If both Hawks and Doves reduced their desired quantity of guns by the
same amount, the Hawks would get a bigger peace dividend because the
production possibilities frontier is much steeper at point H than at
point D. As a result, the reduction of a given number of guns, starting
at point H, leads to a much larger increase in the quantity of butter
produced than when starting at point D.
5. See Figure 7. The shape and position of the frontier depend on how costly it
is to maintain a clean environment the productivity of the environmental industry. Gains in environmental productivity, such as the development of a no-emission auto engine, lead to shifts of the production-possibilities frontier, like the shift from PPF1 to PPF2 shown in the figure.
Figure 7
6. a. A family's decision about how much income to save is microeconomics.
b. The effect of government regulations on auto emissions is
microeconomics.
c. The impact of higher saving on economic growth is macroeconomics.
d. A firm's decision about how many workers to hire is microeconomics.
e. The relationship between the inflation rate and changes in the quantity
of money is macroeconomics.
7. a. The statement that society faces a short-run tradeoff between inflation
and unemployment is a positive statement. It deals with how the
economy is, not how it should be. Since economists have examined data
and found that there is a short-run negative relationship between
inflation and unemployment, the statement is a fact, thus it is a
positive statement.
b. The statement that a reduction in the rate of growth of money will reduce
the rate of inflation is a positive statement. Economists have found
that money growth and inflation are very closely related. The
statement thus tells how the world is, and so it is a positive statement.
c. The statement that the Federal Reserve should reduce the rate of growth
of money is a normative statement. It states an opinion about
something that should be done, not how the world is.
d. The statement that society ought to require welfare recipients to look
e. The statement that lower tax rates encourage more work and more
cases. So the statement reflects how the world is, and is thus a
positive statement.
8.
the federal budget is to be balanced, it should be done over the business
changes that should be made, rather than statements of fact, so they are
normative statements.
The other statements in the table are positive. All the statements concern
the world is, not how the world should be. Note that in all cases, even
them. You could say that positive statements are statements of fact about
the world is, but not everyone agrees about what the facts are.
9. As the president, you'd be interested in both the positive and normative
of economists, but you'd probably be most
works. They know many facts about the economy and the interaction of
sectors. So you would be most likely to call on them about questions of
fact positive analysis. Since you are the president, you are the one who
political consequences. The normative statements made by economists
their own views, not necessarily your views or the electorate’s views.
10. There are many possible answers.
11. As of this writing, the chairman of the Federal Reserve is Alan Greenspan,
chair of the Council of Economic Advisers is R. Glen Hubbard, and the
of the treasury is Paul H. O’Neill.
12. As time goes on, you might expect economists to disagree less about public
and they can be evaluated better. It's likely that the disagreement about
will be reduced after they've been tried in practice. For example, many
economists thought that wage and price controls would be a good idea for
inflation under control, while others thought it was a bad idea. But when
Figure 1
Examples of things that would shift the demand curve include changes in income, prices of related goods like soda or hot dogs, tastes, expectations about future income or prices, and the number of buyers.
A change in the price of pizza would not shift this demand curve; it would only
lead us to move from one point to another along the same demand curve.
3. Here is an example of a supply schedule for pizza:
Price of Pizza Slice Number of Pizza Slices Supplied $ 0.00 0
0.25 100
0.50 200
0.75 300
1.00 400
1.25 500
1.50 600
1.75 700
2.00 800
2.25 900
2.50 1000
The supply curve is graphed in Figure 2.
Figure 2
Examples of things that would shift the supply curve include changes in prices of inputs like tomato sauce and cheese, changes in technology like more
efficient pizza ovens or automatic dough makers, changes in expectations about the future price of pizza, or a change in the number of sellers.
A change in the price of pizza would not shift this supply curve; it would only
move from one point to another along the same supply curve.
4. If the price of tomatoes rises, the supply curve for pizza shifts to the left
because of the increased price of an input into pizza production, but there is no effect on demand. The shift to the left of the supply curve causes the equilibrium price to rise and the equilibrium quantity to decline, as Figure
3 shows.
If the price of hamburgers falls, the demand curve for pizza shifts to the left because the lower price of hamburgers will lead consumers to buy more hamburgers and less pizza, but there is no effect on supply. The shift to the left of the demand curve causes the equilibrium price to fall and the equilibrium
quantity to decline, as Figure 4 shows.
微观经济学（曼昆）案例分析练习题 https://www.doczj.com/doc/6a4506347.html,/ 1、假设我们有以下自行车的市场供给与需求表： a．画出自行车的供给曲线和需求曲线。 b．自行车的均衡价格是多少? c．自行车的均衡数量是多少? d．如果自行车的价格是100美元，存在过剩还是短缺?有多少单位过剩或短缺?这将引起价格上升还是下降？ e．如果自行车的价格是400美元，存在过剩还是短缺?有多少单位过剩或短缺?这将引起价格上升还是下降? f.假设自行车市场的工会为增加工资而谈判。此外，再假设这个事件增加了生产成本，使自行车制造不利，而且，在每种自行车价格时减少了自行车供给量20辆。在图4_2中画出新的供给曲线以及原来的供给和需求曲线。自行车市场新的均衡价格和数量是多少? 【参考答案】： a．
b ．300美元。 c ．50辆自行车。 d ．短缺，70—30=40单位，价格将上升。 e ．过剩，60—40=20单位，价格将下降。 f.均衡价格为400美元，均衡数量为40辆自行车。 2、假设《每日新闻》估计，如果它把自己报纸的价格从1美元提高到1．5美元，那么订 户数就将从5万下降到4万。 a ．当用中点法计算弹性时，《每日新闻》的需求价格弹性是多少? b ．使用中点法的好处是什么? c ．如果《每日新闻》只关心总收益最大化，它应该把报纸的价格从1美元提高到1．5美元吗?为什么该提价或不该提价? 【参考答案】： a ．(10000／45000)／(0.50美元/1.25美元)=0.56。 b ．用中点法的好处是，无论你从价格为1美元开始上升到1.5美元，还是从1.5美元开始下降到1美元，弹性的值是相同的。 c ．应该提价。因为需求价格弹性小于1(缺乏弹性)，价格上升将增加总收益。 3、对下列每一对物品，你预期哪一种物品更富有供给弹性?为什么? a ．电视；海滩的地产
Chapter 8 Application: The Costs of Taxation Test A 1. A tax levied on the buyers of a product shifts the a. demand curve upward or to the right. b. demand curve downward or to the left. c. supply curve upward or to the left. d. supply curve downward or to the right. ANSWER: b. demand curve downward or to the left. TYPE: M KEY1: D SECTION: 1 OBJECTIVE: 1 RANDOM: Y 2. When a tax is levied on a good a. buyers are worse off but sellers are not. b. sellers are worse off but buyers are not. c. neither buyers nor sellers are worse off. d. both buyers and sellers are worse off. ANSWER: d. both buyers and sellers are worse off. TYPE: M KEY1: D SECTION: 1 OBJECTIVE: 1 RANDOM: Y 3. When a tax on a good is enacted, a. sellers always bear the full burden of the tax. b. buyers always bear the full burden of the tax. c. buyers and sellers share the burden of the tax regardless of which party it is levied on. d. sellers bear the full burden if the tax is levied on them, but buyers bear the full burden if the tax is levied on them. ANSWER: c. buyers and sellers share the burden of the tax regardless of which party it is levied on. TYPE: M KEY1: C SECTION: 1 OBJECTIVE: 1 RANDOM: Y 4. A tax placed on a good a. causes the price of the good to fall. b. causes the size of the market for the good to shrink. c. affects buyers of the good, but not sellers. d. is usually borne entirely by the seller of the good. ANSWER: b. causes the size of the market for the good to shrink. TYPE: M KEY1: C SECTION: 1 OBJECTIVE: 1 RANDOM: Y 5. When a tax is levied on a good a. the market price falls because demand declines. b. the market price falls because supply falls. c. the market price rises because demand falls. d. a wedge is placed between the price buyers pay and the price sellers receiv e. ANSWER: d. a wedge is placed between the price buyers pay and the price sellers receive. TYPE: M KEY1: C SECTION: 1 OBJECTIVE: 1 RANDOM: Y
问题与应用 1．描写下列每种情况所面临的权衡取舍： A．一个家庭决定是否买一辆新车。 答：如果买新车就要减少家庭其他方面的开支，如：外出旅行，购置新家具；如果不买新车就享受不到驾驶新车外出的方便和舒适。 B．国会议员决定对国家公园支出多少。 答：对国家公园的支出数额大，国家公园的条件可以得到改善，环境会得到更好的保护。但同时，政府可用于交通、邮电等其他公共事业的支出就会减少。 C．一个公司总裁决定是否新开一家工厂。 答：开一家新厂可以扩大企业规模，生产更多的产品。但可能用于企业研发的资金就少了。这样，企业开发新产品、利用新技术的进度可能会减慢。 D．一个教授决定用多少时间备课。 答：教授若将大部分时间用于自己研究，可能会出更多成果，但备课时间减少影响学生授课质量。E．一个刚大学毕业的学生决定是否去读研究生。 答：毕业后参加工作，可即刻获取工资收入；但继续读研究生，能接受更多知识和未来更高收益。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55%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)。 5．你管理的公司在开发一种新产品过程中已经投资500万美元，但开发工作还远远没有完成。在最近的一次会议上，你的销售人员报告说，竞争性产品的进入使你们新产品的预期销售额减少为300万美元。如果完成这项开发还要花费100万美元，你还应该继续进行这项开发吗？为了完成这项开发，你的最高花费应该是多少?? 答：还应该继续这项开发。因为现在它的边际收益是300 万美元，而边际成本是100 万美元。为了完成这项开发我最多能再花300 万美元。只要边际收益大于边际成本，就有利可图。 6．魔力饮料公司的三位经理正在讨论是否要扩大产量。每位经理提出了做出这个决策的一种方法：哈利：我们应该考查一下我们公司的生产率——每个工人生产的加仑数——将上升还是下降。 罗恩：我们应该考查一下我们的平均成本——每个工人的成本——将上升还是下降。 赫敏：我们应该考查一下多卖一加仑饮料的额外收益，大于还是小于额外的成本。你认为谁对？答：我认为赫敏提出的决策方法正确。因为只有多卖一加仑饮料的额外收益大于它的额外成本时，多卖一加仑饮料才是有利可图的。理性人应该考虑边际量。 77．社会保障制度为65岁以上的人提供收入。如果一个社会保障的领取者决定去工作并赚一些钱，他(或她)所领到的社会保障津贴通常会减少。 A．提供社会保障如何影响人们在工作时的储蓄激励? 答：社会保障的提供使人们退休以后仍可以获得收入，以保证生活。因此，人们不用为不能工作时的生活费而发愁，人们在工作时期的储蓄就会减少。
WHAT’S NEW IN THE S EVENTH EDITION: A new Case Study on Left-Digit Bias has been added and a new In the News feature on "Can Brain Science Improve Economics" has been added. LEARNING OBJECTIVES: By the end of this chapter, students should understand: how to examine problems caused by asymmetric information. the market solutions to asymmetric information. why democratic voting systems may not represent the preferences of society. why people may not always behave as rational maximizers. CONTEXT AND PURPOSE: Chapter 22 is the last chapter in the microeconomics portion of the text. It is the second of two unrelated chapters that introduce students to advanced topics in microeconomics. These two chapters are intended to whet their appetites for further study in economics. The purpose of Chapter 22 is to give students a taste of three topics on the frontier of microeconomic research. The first topic addressed is asymmetric information , a situation when one person in an economic relationship has more relevant knowledge than the other person does. The second topic is political economy , the application of economic tools to the understanding of the functioning of government. The third topic addressed is behavioral economics , the introduction of psychology into the study of economic issues. 22 FRONTIERS OF MICROECONOMICS
1. Describe some of the trade-offs faced by each of the following: a. a family deciding whether to buy a new car b. a member of Congress deciding how much to spend on national parks c. a company president deciding whether to open a new factory d. a professor deciding how much to prepare for class e. a recent college graduate deciding whether to go to graduate school 2. You are trying to decide whether to take a vacation. Most of the costs of the vacation (airfare, hotel, and forgone wages) are measured in dollars, but the benefits of the vacation are psychological. How can you compare the benefits to the costs? 3. You were planning to spend Saturday working at your part-time job, but a friend asks you to go skiing. What is the true cost of going skiing? Now suppose you had been planning to spend the day studying at the library. What is the cost of going skiing in this case? Explain. 4. You win $100 in a basketball pool. You have a choice between spending the money now or putting it away for a year in a bank account that pays 5 percent interest. What is the opportunity cost of spending the $100 now? 5. The company that you manage has invested $5 million in developing a new product, but the development is not quite finished. At a recent meeting, your salespeople report that the introduction of competing products has reduced the expected sales of your new product to $3 million. If it would cost $1 million to finish development and make the product, should you go ahead and do so? What is the most that you should pay to complete development? 6. The Social Security system provides income for people over age 65. If a recipient of Social Security decides to work and earn some income, the amount he or she receives in Social Security benefits is typically reduced.
曼昆经济学原理答案30—34
第十二篇短期经济波动 第三十一章总需求与总供给 复习题 1．写出当经济进入衰退时下降的两个宏观经济变量的名字。写出当经济进入衰退时上升的一个宏观经济变量的名字。 答：当经济进入衰退时，实际GDP和投资支出下降，失业率上升。 2．画出一个有总需求、短期总供给和长期 总供给的曲线的图。仔细地标出正确的轴。 答： 图31—1 经济的长期均衡 3．列出并解释总需求曲线向右下方倾斜的 三个原因。 答：为了理解总需求曲线向右下 方倾斜的原因，我们必须考察物价水平如何影响消费、投资和净出口的物品与劳务需求量。 (1)庇古的财富效应
物价水平下降使消费者感到更富裕，这又鼓励他们更多地支出，消费支出增加意味着物品与劳务的需求量更大。 (2)凯恩斯的利率效应 较低的物价水平降低了利率，鼓励了家庭和企业更多地支出于投资物品，从而增加了物品与劳务的需求量。 (3)蒙代尔——弗莱明汇率效应 当美国物价水平下降引起美国利率下降时，实际汇率贬值，而且这种贬值刺激了美国的净出口，从而增加了国外对美国物品与劳务的需求量。 由于这三个原因，总需求曲线向右下方倾斜。 4．解释为什么长期总供给曲线是垂线。 答：在长期中，一个经济的物品与劳务的供给取决于它资本与劳动的供给，以及用来把资本与劳动变为物品与劳务的生产技术。由于物价水平并不影响这些实际GDP的长期决定因素，所以长期总供给曲线是一条垂线，即经济的资本、劳动和技术决定了物品与劳务供给量，而且，无论物价水平如何变动，供给量都是相同的。
5．列出并解释为什么短期总供给曲线向右上方倾斜的三种理论。 答：在短期中，总供给曲线向右上方倾斜，也就是说，在一个一两年的时期中，经济中物价总水平的上升增加了物品与劳务的供给量，而物价水平下降倾向于减少物品与劳务供给量。什么因素引起物价水平与产量之间的正相关关系呢?宏观经济学家提出了三种理论说明短期总供给曲线的向右上方倾斜。在每一种理论中，一种特殊的市场不完全性引起经济中供给一方的短期状况与长期不同。虽然每一种理论在细节上不同，但它们具有共同的内容：当物价水平背离了人们预期的物价水平时，供给量就背离了其长期水平或“自然水平”。当物价水平高于预期水平时，产量就高于其自然率。当物价水平低于预期水平时，产量就低于其自然率。 (1)新古典的错觉理论 根据这种理论，物价总水平的变动会暂时误导供给者对他们出售其产品的市场发生的变动的看法。由于这些短期的错觉，供给者对物价水平的变动作出了反应，而这种反应引起了向右上方倾斜的总供给曲线。假设物价总水平降到低于
第六章、第七章练习题 一、判断 1．某厂商产量达到5万时的MR=65元，MC=55元，（其它条件一定）该厂商应继续扩大产量. 2. 完全竞争厂商只能被动地接受既定的市场价格。 3. 完全竞争条件下，行业所面临的需求曲线是一条水平线。 4. 完全竞争厂商的短期供给曲线是短期边际成本曲线上等于和高于停止营业点的部分。 5. 完全竞争厂商的平均收益曲线和边际收益曲线与需求曲线是相同的。 6. 完全竞争厂商实现短期均衡时，定可获得大于零的经济利润。 7. 当一个完全竞争行业实现长期均衡时，每个企业都实现了正常利润，且经济利润都为零。 8. 在厂商短期均衡产量上，当AR＜SAC 且AR＞AVC时，厂商亏损，但应继续生产。 9. 在完全竞争市场上，SMC曲线和SAC 曲线的交点，被称为停止营业点。 10.垄断行业由于有规模经济可以比竞争行业产量更高，价格更低 11.完全竞争市场与垄断竞争市场的差别是后者可以影响产品的价格. 12.在完全竞争产品市场，厂商的短期反供给函数为P = SMC =f(Q)。 二、选择题 1、在完全竞争市场上，厂商短期均衡条件是（） A、P=AR B、P=MR C、P=MC D、P=AC 2、在垄断竞争中（） A、为数很少的厂商，有差异的产品 B、许多厂商，同质的产品； C、为数很少几个厂商，同质产品 D、许多厂商，有差异的产品 3、在一般情况下，厂商得到的价格若低于下述哪种成本，他将停止营业？（）A、平均可变成本 B、平均成本 C、平均不变成本 D、边际成本 4、在短期，完全垄断厂商（） A、无盈亏 B、取得最大利润 C、发生亏损 D、以上情况都可能出现 5、下列描述中，不属于完全垄断厂商实行差别定价的条件是（） A、市场存在不完全性 B、各个市场的需求弹性不同； C、市场未达到均衡状态 D、市场必须能有效地分离开来。 6、寡头垄断厂商的产品是（） A、同质的 B、有差异的 C、既可以是同质的，也可以是有差异的 D、以上都不对 7、P=MC的最大利润原则（） A．适用于任何条件下的厂商。 B、仅适用于完全竞争条件下的厂商。C．仅适用于非完全竞争的厂商。 D．所有的市场结构都不能适用。 8、在完全竞争市场上（） A、产品不同质 B、要素不能自由流动 C、信息不畅通 D、价格既定 9、在完全竞争市场的收支相抵点上（） A、P=SAC B、 P=LAC C、P=AVC D、MR=AVC 10、如果某厂商的平均收益曲线从水平线变为向右下方倾斜的曲线，说明（）。A、既有厂商进入也有厂商退出该行业 B、完全竞争被不完全竞争所取代 C、新的厂商进入了该行业 D、原有的厂商退出了该行业11、对一个垄断竞争企业来说，平均收益曲线（）。 A、和企业的需求曲线一样，边际收益曲线在企业的需求曲线之下。 B、在企业的需求曲线之上，边际收益曲线在企业的需求曲线之下。 C、在企业的需求曲线之上，边际收益曲线与企业的需求曲线相同。 D、和边际收益曲线一样都与企业的需求曲线相同。
曼昆微观经济学英文版课后练习题第一章
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1 Chapter 1 Ten Principles of Economics Multiple Choice 1. The word that comes from the Greek word for "one who manages a household" is a. market. b. consumer. c. producer. d. economy. ANS: D DIF: 1 REF: 1-0 TOP: Economy MSC: Definitional 2. The word “economy” comes from the Greek word oikonomos , which means a. “environment.” b. “production.” c. “one who manages a househol d.” d. “one who makes decisions.” ANS: C DIF: 1 REF: 1-0 TOP: Economy MSC: Definitional 3. Resources are a. scarce for households but plentiful for economies. b. plentiful for households but scarce for economies. c. scarce for households and scarce for economies. d. plentiful for households and plentiful for economies. ANS: C DIF: 1 REF: 1-0 TOP: Resources, Scarcity MSC: Interpretive 4. Economics deals primarily with the concept of a. scarcity. b. poverty. c. change. d. power. ANS: A DIF: 1 REF: 1-0 TOP: Scarcity MSC: Definitional 5. Which of the following questions is not answered by the decisions that every society must make? a. What determines consumer preferences? b. What goods will be produced? c. Who will produce the goods? d. Who will consume the goods? ANS: A DIF: 2 REF: 1-0 TOP: Economies MSC: Interpretive 6. The overriding reason as to why households and societies face many decisions is that a. resources are scarce. b. goods and services are not scarce. c. incomes fluctuate with business cycles. d. people, by nature, tend to disagre e. ANS: A DIF: 2 REF: 1-0 TOP: Scarcity MSC: Interpretive 7. The phenomenon of scarcity stems from the fact that a. most economies’ production methods are not very good. b. in most economies, wealthy people consume disproportionate quantities of goods and services. c. governments restricts production of too many goods and services. d. resources are limited. ANS: D DIF: 2 REF: 1-0 TOP: Scarcity MSC: Interpretive
一、名词解释（每小题5分，共50分） 1.机会成本 2.科斯定理 3.搭便车 4.囚徒困境 5.菲利普斯曲线 6.供应学派 7.凯恩斯革命 8.看不见的手 9.比较优势 10.外部性 二、简述题（第11、12、13题各12分，14题14分，共50分） 1.简述银行存款的创造过程。 2.简述失业的根源及其类型。 3.简述节俭的是非。 4.根据有关经济学原理，简析我国森林减少、珍稀动物来绝的原因及解决的措施。 三、论述题(每小题25分，共计50分) 1.论述人民币升值对中国经济的影响。 2.论述政府公共投资对国民经济的作用。 一、名词解释（每小题5分，共50分） 1.机会成本:指人们利用一定资源获得某种收入时所放弃的在其他可能的用途中所能够获取的最大收入。生产一单位的某种商品的机会成本是指生产者所放弃的使用相同的生产要素在其他生产用途中所能得到的最高收入。机会成本的存在需要三个前提条件。第一，资源是稀缺的；第二，资源具有多种生产用途；第三，资源的投
向不受限制。从机会成本的角度来考察生产过程时，厂商需要将生产要素投向收益最大的项目，而避免带来生产的浪费，达到资源配置的最优。机会成本的概念是以资源的稀缺性为前提提出的。从经济资源的稀缺性这一前提出发，当一个社会或一个企业用一定的经济资源生产一定数量的一种或者几种产品时，这些经济资源就不能同时被使用在其他的生产用途方面。这就是说，这个社会或这个企业所能获得的一定数量的产品收入，是以放弃用同样的经济资源来生产其他产品时所能获得的收入作为代价的。这也是机会成本产生的缘由。因此，社会生产某种产品的真正成本就是它不能生产另一些产品的代价。所以，机会成本的含义是：任何生产资源或生产要素一般都有多种不同的使用途径或机会，也就是说可以用于多种产品的生产。但是当一定量的某种资源用于生产甲种产品时，就不能同时用于生产乙种产品。因此生产甲种产品的真正成本就是不生产乙种产品的代价，或者是等于该种资源投放于乙种产品生产上可能获得的最大报酬。一种资源决定用于甲种产品，就牺牲了生产其他产品的机会；从事生产甲种产品的收入，是由于不从事或放弃其他产品生产的机会而产生的。 2.科斯定理:指一种产权理论。科斯本人并未将科斯定理写成文字，科斯定理的提出是由其好友斯蒂格勒首先根据科斯于20世纪60年代发表的《社会成本问题》这篇论文的内容概括出来的。其内容是：只要财产权是明确的，并且其交易成本为0或者很小，则无论在开始时财产权的配置是怎么样的，市场均衡的最终结果都是有效率的。科斯定理进一步扩大了“看不见的手”的作用。按照这个定理，只要那些假设条件成立，则外部影响就不可能导致资源配置不当。或者以另一角度来说，在所给条件下，市场力量足够强大，总能够使外部影响以最经济的办法来解决，从而仍然可以实现帕累托最优状态。西方学者认为，明确的财产权及其转让可以使得私人成本（或利益）与社会成本（或利益）趋于一致。以污染问题为例，科斯定理意味着，一旦所需条件均被满足，则污染者的私人边际成本曲线就会趋于上升，直到与边际社会成本曲线完全重合，从而污染者的利润最大化产量将下降至社会最优产量水平。 科斯定理解决外部影响问题在实际中并不—定真的有效。资产的财产权不一定总是能够明确地加以规定；已经明确的财产权不一定总是能够转让；分派产权会影响收入分配，而收入分配的变动可以造成社会不公平，引起社会动乱。在社会动乱的情况下，就谈不上解决外部效果的问题了。 3.搭便车：指不付成本或支付很低的成本而消费公共产品的行为。公共产品的特点决定了私人厂商不愿自动提供这种产品。这是因为在公用产品消费中存在“搭便车”问题，即每个人都想不付任何成本，或只支付很低的代价，来享受公共产品的服务。由于公共物品具有消费的非竞争性和受益的非排他性，人们可以在不付费的情况下享受公共物品所带来的效益。因此公共产品覆盖的消费者人数越多，搭便车问题就越严重，公共产品由私人厂商提供出来的可能性就越小。例如：1970年美国通用汽车公司研制出了一种汽车污染物排放控制装置，每个售价20美金，如果每个车尾都装上这一装置，可使汽车排放的污染下降30％至50％。然而，污染的降低是一种公共产品，每个人呼吸空气质量是否改善并不取决于自己的车上是否装上这个新发明，而是取决于该地区大多数车主的选择，于是大多数人都不想多花20美元而只是试图搭便车，结果，在私人市场上，这种公共产品的产量总难以达到最佳水平。私人不能提供公共产品，就只能由政府出面担当此项职能。事实上，私人经济中的政府，最初就是为了提供公共产品(法律、国防、公安等等)的目的由众多私人共同建立起来的。政府这一职能具体体现为：①尽可能正确地估价社会对公用产品的实际需求；②按照社会福利最大化的原则确定税收比率，并用税收收入购置公用产品，为公众提供服务。 4.囚徒困境：指两个被捕获的囚犯之间的一种特殊“博弈”，说明为什么甚至在合作对双方有利时，保持合作也是困难的。囚犯两难处境的故事包含着一个一般性的结论，这个结论适用于任何一个力图维持其成员合作的集团。这是博弈论中的一个经典例证，同一市场上的寡头在力图达到垄断结果时的博弈类似于两个处于两难处境的囚犯的博弈。具体情况如下：两囚徒被指控是一桩罪案的同案犯。他们被分关在不同的牢房且无法互通信息。各囚徒都被要求坦白罪行。如果两囚徒都坦白，各将被判入狱5年；如果两人都不坦白，则很难对他们提起刑事诉讼，因而两囚徒可以期望被从轻发落为入狱2年；另一方面，如果一个囚徒坦白而另一个囚徒不坦白，坦白的囚徒就只需入狱1年，而另一个将被判入狱10年。那么囚徒将会怎么选择呢？下表归纳了各种可能的结果。（其中“得益”是负的，表格右下角单元格意思是两个囚徒各2年徒刑）。该表说明，这两个囚徒面临着一种困境。如果他们都不坦白（以一种会遵守的方法），那么两人只需入狱仅仅2年。但他们不能相互讲话，如果囚徒A不坦白，他就冒着被B利用的危险。因为不管囚徒A怎么选择，囚徒B坦白总是最优方案。
Examine why people tend to use common r esour ces too much Consider some of the impor tant common r esour ces in our economy Consider some of the impor tant public goods in our economy Lear n t he def ini ng characteristics of public goods and common r esour ces Examine why private markets fail to pr ovide public goods See why the cost-benefit analysis of public goods is both necessar y and dif ficult An old song lyric maintains that “the best things in life are free.” A moment’s thought reveals a long list of goods that the songwriter could have had in mind. Na-ture provides some of them, such as rivers, mountains, beaches, lakes, and oceans.The government provides others, such as playgrounds, parks, and parades. In each case, people do not pay a fee when they choose to enjoy the benefit of the good.Free goods provide a special challenge for economic analysis. Most goods in our economy are allocated in markets, where buyers pay for what they receive and sellers are paid for what they provide. For these goods, prices are the signals that guide the decisions of buyers and sellers. When goods are available free of charge,however, the market forces that normally allocate resources in our economy are absent. In this chapter we examine the problems that arise for goods without market prices. Our analysis will shed light on one of the Ten Principles of Economics P U B L I C G O O D S A N D C O M M O N R E S O U R C E S 225
Chapter 5 Elasticity and Its Application TRUE/FALSE 1. Elasticity measures how responsive quantity is to changes in price. ANS: T DIF: 1 REF: 5-0 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Definitional 2. Measures of elasticity enhance our ability to study the magnitudes of changes. ANS: T DIF: 1 REF: 5-0 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Definitional 3. The demand for bread is likely to be more elastic than the demand for solid-gold bread plates. ANS: F DIF: 2 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 4. In general, demand curves for necessities tend to be price elastic. ANS: F DIF: 1 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 5. In general, demand curves for luxuries tend to be price elastic. ANS: T DIF: 1 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 6. Necessities tend to have inelastic demands, whereas luxuries have elastic demands. ANS: T DIF: 2 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 7. Goods with close substitutes tend to have more elastic demands than do goods without close substitutes. ANS: T DIF: 2 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 8. The demand for Rice Krispies is more elastic than the demand for cereal in general. ANS: T DIF: 2 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 9. The demand for soap is more elastic than the demand for Dove soap. ANS: F DIF: 2 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 10. The demand for gasoline will respond more to a change in price over a period of five weeks than over a period of five years. ANS: F DIF: 2 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 11. Even the demand for a necessity such as gasoline will respond to a change in price, especially over a longer time horizon. ANS: T DIF: 2 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Interpretive 12. The price elasticity of demand is defined as the percentage change in quantity demanded divided by the percentage change in price. ANS: T DIF: 1 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Definitional 13. The price elasticity of demand is defined as the percentage change in price divided by the percentage change in quantity demanded. ANS: F DIF: 1 REF: 5-1 NAT: Analytic LOC: Elasticity TOP: Price elasticity of demand MSC: Definitional 288