曼昆经济学原理微观经济学英文版习题答案(考试章节筛选)
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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 becau 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 becau as they compare benefits to costs, a
change in incentives may cau 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)
乔布斯演讲视频governments can sometimes improve market outcomes. Trade can make everyone better off
becau it allows countries to specialize in what they do best and to enjoy a wider variety of
goods and rvices. Markets are usually a good way to organize economic activity becau
the invisible hand leads markets to desirable outcomes. Governments can sometimes
improve market outcomes becau sometimes markets fail to allocate resources efficiently
becau 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 rvices; (2) prices ri when
the government prints too much money; and (3) society faces a short-run tradeoff between
inflation and unemploy ment. A country’s standard of living depends on its ability to
produce goods and rvices, 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 ri when the government prints too much money becau 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.pasha
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 u your last ten dollars on pizza or on a study guide for that tough economics
cour).
2. The opportunity cost of eing 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 el 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 dert 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 at belts shows that policy actions
can have quite unintended conquences. 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 lors and some winners becau 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 reprents the idea that even though individuals and
firms are all acting in their own lf-interest, prices and the marketplace guide them to do
complete什么意思what is good for society as a whole.
sundays
7. The two main caus 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.
cauway bay8. Productivity is important becau a country's standard of living depends on its ability to
produce goods and rvices. The greater a country's productivity (the amount of goods and
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rvices produced from each hour of a worker's time), the greater will be its standard of
living.
9. Inflation is an increa in the overall level of prices in the economy. Inflation is caud by
increas 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 increa spending on national parks,
the tradeoff is between parks and other spending items or tax cuts. If more moneywork out
goes into the park system, that may mean less spending on national defen 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
bad on whether the new factory will increa 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 increa 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 rearch.
2. When the benefits of something are psychological, such as going on a vacation, it isn't easy
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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 t of golf clubs? Then you
can decide if you'd rather have the new clubs or the vacation. A cond 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.
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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 cour.
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 loss 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 ri 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 wh ether 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 increas 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, suppo
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
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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 u. If you make
too many CDs and not enough castte tapes, people with castte 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 aris becau condhand smoke harms nonsmokers.
d. Efficiency: The market failure occurs becau of Standard Oil's monopoly power.
e. Equity
f. Efficiency: There is an externality becau of accidents caud by drunk drivers.
stiff12. 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 ca. 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 increa
by providing more health care. But more likely, if the government mandated
incread spending on health care, the economy would be less efficient becau it
would give people more health care than they would choo 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 reprent 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.
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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 economy 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 incread productivity, so that an hour of work
produces more goods and rvices than it ud to. Thus incomes have continuously rin
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 increa
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, becau 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
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