复习题：

1，Explain how absolute advantage and comparative advantage differ. 绝对优势和比较优势区别。

答案：绝对优势反映一个人、公司或国家与另外一个人、公司或国家相比，其生产率水平的高低。

     比较优势其实是基于不同人、公司和国家的机会成本来比较。

     一个国家、公司或个人，可能在生产所有产品中都具有绝对优势，但是不可能都具有比较优势。

 

2，Give an example in which one person has an absolute advantage in doing something but another person has a comparative advantage. 举出一例，说明某人有绝对优势做一些事情，而另一个人则有比较优势。

 

答案：小李和小张都是修理工。小李每天可修理10台电视机，或20台洗衣机。而小张每天能修理15台电视机或30台洗衣机。

      很明显，小张无论修电视机还是洗衣机都具有绝对优势。

      现在考虑机会成本---

      小李修一台电视机的机会成本是“修2台洗衣机”，修一台洗衣机的机会成本是“修0.5台电视机”。

      小张修一台电视机的机会成本是“修2台洗衣机”，修一台洗衣机的机会成本是“修0.5台电视”。

      所以，小张和小李在修理洗衣机和电视机方面，都没有比较优势。

 

      改变一下条件，小张每天能修理15台电视机，或25台洗衣机。那么小张修一台电视机的机会成本是“修1.67台洗衣机”，修一台洗衣机的机会成本是“修0.6台电视”。这样小张修洗衣机的机会成本就高于小李，不具有比较优势。所以，小张应该专门修电视机，而小李专门修洗衣机。

 

3, Is absolute advantage or comparative advantage more important for trade? explain your reasoning, using the example in your answer to Question 2.对贸易而言，是绝对优势重要还是相对优势重要。用题2做说明。

答案：相对优势重要。

 

4，Will a nation tend to export or import goods for which it has a comparative advantage? Explain. 一个国家倾向于出口还是进口其有比较优势的产品？

答案：出口。

 

5，Why do economists oppose policies that restrict trade among nations? 为何经济学家反对政客限制国家之间贸易的做法？

答案：每个国家都有比较优势，通过国际贸易，能促进贸易国的繁荣。

 

应用题：

1，Consider the farmer and the rancher from our example in this chapter. Explain why the farmer’s opportunity cost of producing 1 pound of meat is 2 pounds of
potatoes. Explain why the rancher’s opportunity cost of producing 1 pound of meat is 1/8 pound of potatoes.

答案：略。因牵涉到课本举例。

 

2，Maria can read 20 pages of economics in an hour. She can also read 50 pages of sociology in an hour. She spends 5 hours per day studying.玛利雅每小时可以阅读《经济学》20页或《社会学》50页。她每天阅读5小时。
a. Draw Maria’s production possibilities frontier for reading economics and sociology. 绘出玛利雅的“阅读可能性”曲线。

答案：

 

b. What is Maria’s opportunity cost of reading 100 pages of sociology? 玛利雅阅读100页《社会学》的机会成本是什么？

答案：40 页经济学

 

3. American and Japanese workers can each produce 4 cars a year. An American worker can produce 10 tons of grain a year, whereas a Japanese worker can produce
5 tons of grain a year. To keep things simple, assume that each country has 100 million workers.美国和日本工人每年每人都可以制造4辆小汽车。美国工人每人每年能生产10吨谷物，日本工人每年则生产5吨谷物。为了使问题简单化，假设两个都有100百万工人。
a. For this situation, construct a table analogous to Table 3-1.作出类似表3-1的图标。

答案：略。

 

b. Graph the production possibilities frontier of the American and Japanese economies. 绘出美国和日本的生产可能性边界曲线。

c. For the United States, what is the opportunity cost of a car? Of grain? For Japan, what is the opportunity cost of a car? Of grain? 对美国而言，一辆汽车的机会成本是什么？一吨谷物的机会成本是什么？对日本呢？

答案：对美国，每辆汽车的机会成本是2.5 顿谷物，每吨谷物的机会成本是2/5辆汽车。
      对日本，汽车的机会成本是5/4吨谷物，每吨谷物的机会成本是4/5辆汽车。

 

d. Which country has an absolute advantage in producing cars? In producing grain? 哪个国家有生产汽车的绝对优势？哪个国家有生产谷物的绝对优势？

答案：美日都没有生产汽车的绝对优势。

      美国有生产谷物的绝对优势。

 

e. Which country has a comparative advantage in producing cars? In producing grain? 哪个国家有生产汽车的比较优势？哪个国家有生产谷物的比较优势？

答案：日本有生产汽车比较优势。美国有生产谷物比较优势。

 

f. Without trade, half of each country’s workers produce cars and half produce grain. What quantities of cars and grain does each country produce? 不发生贸易，每个国家的工人一半生产汽车，一半生产谷物。则每个国家汽车和谷物产量各是多少？

答案：美：200百万汽车，500百万吨谷物。
      日：200百万汽车，250百万吨谷物。

g. Starting from a position without trade, give an example in which trade makes each country better off.从没有贸易出发，举例说明贸易使美国国家状况变好。

答案：假如美国从生产汽车的工人中，抽调出一人去生产谷物。则美国汽车产量将减少4辆，达到199，999，996辆，而谷物产量将增加10吨，达到500，000，010吨（不考虑编辑产量递减）。假设日本从生产谷物的工人中抽调一人去生产汽车，则汽车产量增加4辆，达到200，000，004辆，而谷物产量减少达到249，999，995吨。现在日本用4辆汽车去交换美国谷物，4辆汽车交换8吨谷物，则美国和日本将拥有的汽车数均恢复到200百万辆。日本将拥有谷物249，999，995+32=250百万吨+3吨，比交换前增加了3吨。而美国将拥有的谷物量为500百万吨+2吨，比交换前增加了2吨，所以贸易使日美均受益。

 

4. Pat and Kris are roommates. They spend most of their time studying (of course), but they leave some time for their favorite activities: making pizza and brewing root beer. Pat takes 4 hours to brew a gallon of root beer and
2 hours to make a pizza. Kris takes 6 hours to brew a gallon of root beer and 4 hours to make a pizza.帕特和克里斯是室友。大部分时间用来学习（当然），但是闲暇时间他们做课外活动：制作比萨饼和无醇饮料。帕特用4小时可以酿1加仑饮料2小时制作1个比萨饼，而克里斯则分别用6小时和4小时。
a. What is each roommate’s opportunity cost of making a pizza? Who has the absolute advantage in making pizza? Who has the comparative advantage
in making pizza? 他们的制作比萨饼的机会成本？谁有绝对优势？谁有比较优势？

答案：帕特制作比萨饼的机会成本是 0.5 加仑饮料.克里斯是2/3加仑饮料。
      帕特既有制作比萨饼的绝对优势，有有比较优势。

b. If Pat and Kris trade foods with each other, who will trade away pizza in exchange for root beer? 如果帕特和克里斯互相交换产品，谁将用比萨饼换饮料。

答案：帕特。

c. The price of pizza can be expressed in terms of gallons of root beer. What is the highest price at which pizza can be traded that would make both roommates better off? What is the lowest price? Explain. 如果有利可图，比萨饼的价格范围应该是？（用饮料作计价单位）

答案：应该在0.5-2/3加仑饮料之间。
如果价格超过2/3加仑饮料，克里斯将自己酿饮料. 如果价格低于0.5加仑饮料，帕特也没意愿去交换。

 

5. Suppose that there are 10 million workers in Canada, and that each of these workers can produce either 2 cars or 30 bushels of wheat in a year.假设加拿大有10百万工人，每个工人每年可生产2辆小汽车或30蒲式耳小麦。
a. What is the opportunity cost of producing a car in Canada? What is the opportunity cost of producing a bushel of wheat in Canada? Explain the relationship between the opportunity costs of the two goods. 一辆小汽车和一蒲式耳小麦的机会成本各是多少？它们之间是什么关系？

答案：一辆汽车的机会成本是15蒲式耳小麦。一蒲式耳小麦的机会成本是1/15辆卡车。互为倒数。

b. Draw Canada’s production possibilities frontier. If Canada chooses to consume 10 million cars, how much wheat can it consume without trade? Label this point on the production possibilities frontier.绘出加拿大的PPF曲线。如果加拿大决定消费10百万汽车，则能消费多少小麦，在PPT曲线上标出该点。

答案：150 百万蒲式耳小麦，图中A点。

c. Now suppose that the United States offers to buy 10 million cars from Canada in exchange for 20 bushels of wheat per car. If Canada continues to consume 10 million cars, how much wheat does this deal allow Canada to consume? Label this
point on your diagram. Should Canada accept the deal? 假设美国愿意用每20蒲式耳小麦换一辆小汽车的价格换加拿大10百万辆小汽车。如果加拿大继续消费10百万辆汽车，则这笔交易导致加拿大可消费小麦数量为？标出该点，加拿大应该接受这笔交易吗？

答案：加拿大工人全部生产汽车，不再生产小麦。汽车交换的小麦为200百万吨。图中B点。应该接受这笔交易。

 

6. Consider a professor who is writing a book. The professor can both write the chapters and gather the needed data faster than anyone else at his university.
Still, he pays a student to collect data at the library. Is this sensible? Explain. 设想一名教授正在写一本书。该教授写书和收集必要资料都快于大学其他人。但是，他决定付费给学生去图书馆收集资料。这个决定明智吗？

答案：也许教授在写作和收集方面都有优势。但是学生在收集数据方面有比较优势。教授应该付钱让学生收集数据。

 

7. England and Scotland both produce scones and sweaters. Suppose that an English worker can produce 50 scones per hour or 1 sweater per hour. Suppose that a Scottish worker can produce 40 scones per hour or 2 sweaters per hour.英格兰和苏格兰都生产烤饼和汗衫。假设英格兰工人每小时可以生产50个烤饼或1件汗衫。而苏格兰工人每小时可以生产40个烤饼或2件汗衫。

a. Which country has the absolute advantage in the production of each good? Which country has the comparative advantage? 哪个国家在哪种产品有绝对优势？比较优势？

答案：英格兰在生产烤饼方面有绝对优势，苏格兰在生产汗衫方面有绝对优势。

      英格兰：烤饼的机会成本是1/50汗衫。汗衫的机会成本是50个烤饼。
      苏格兰：烤饼的机会成本是1/20汗衫。汗衫的机会成本是20个烤饼。
      这样，英格兰有生产烤饼的比较优势，苏格兰有生产汗衫的比较优势。

b. If England and Scotland decide to trade, which commodity will Scotland trade to England? Explain.如果英格兰和苏格兰决定贸易，苏格兰应该出口什么？解释之。

答案；苏格兰应该出售汗衫。因为有比较优势。

 

c. If a Scottish worker could produce only 1 sweater per hour, would Scotland still gain from trade? Would England still gain from trade? Explain.如果苏格兰工人每小时能生产1件汗衫，苏格兰能从贸易中获益吗？英格兰呢？解释之。

答案：仍然有利。比较优势仍然存在。

 

9. The following table describes the production possibilities of two cities in the country of Baseballia:
         PAIRS OF RED            PAIRS OF  WHITE
         SOCKS PER  WORKER       SOCKS PERWORKER
         PER HOUR                PER HOUR
BOSTON    3                      3
CHICAGO   2                      1

a. Without trade, what is the price of white socks (in terms of red socks) in Boston? What is the price in Chicago? 没有贸易，以红袜子计价的白袜子在波士顿价格是？在芝加哥呢？

答案：在波士顿：每双白袜子的价格与每双红袜子的价格相当。
      在芝加哥：红袜子的价格是1/2白袜子。白袜子的价格是2个红袜子。

 

b. Which city has an absolute advantage in the production of each color sock? Which city has a comparative advantage in the production of each color sock?

答案：波士顿生产红袜子和白袜子都具有绝对优势。
      芝加哥具有生产红袜子的比较优势，而波士顿具有生产白袜子的比较优势。

c. If the cities trade with each other, which color sock will each export?

答案：芝加哥输出红袜子，波士顿输出白袜子。

d. What is the range of prices at which trade can occur? 发生贸易的价格范围是？

答案：对芝加哥而言，当红袜子的价格处于1/2白袜子和1个白袜子之间时。
      对波士顿而言，当白袜子价格处于1和2个红袜子之间时。

 

11. Are the following statements true or false? Explain in each case.判断正误并解释。

a. “Two countries can achieve gains from trade even if one of the countries has an absolute advantage in the production of all goods.”即使一个国家在所有产品生产中都有绝对优势，贸易双方也可从贸易中获益。

答案：对。

b. “Certain very talented people have a comparative advantage in everything they do.” 某些有天赋的人在做任何事情时，都有比较优势。

答案：错。

c. “If a certain trade is good for one person, it can’t be good for the other one.” 如果贸易有利于一方，必定不利于另一方。

答案：错。