国际经济学第三章答案

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6 Chapter 3

1．Home has 1200 units of labor available. It can produce two goods, apples and bananas.

The unit labor requirement in apple production is 3, while in banana production it is 2.

a．Graph out the production possibilities frontier:

b．What is the opportunity cost of apples in terms of bananas?

5.1LbLaaa

c．In the absence of trade, what would the price of apples in terms of bananas be?

In the absence of trade, since labor is the only factor of production and supply decisions are

determined by the attempts of individuals to maximize their earnings in a competitive

economy, only when LbLaba/aa /PPwill both goods be produced. So 1.5 /PPba

2．Home is as described in problem 1. There is now also another country, Foreign, with a

labor force of 800. Foreign’s unit labor requirement in apple production is 5, while in

banana production it is 1.

a．Graph Foreign’s production possibilities frontier:

b．Construct the world relative supply curve. 0200400600800200400600800QbananaQapple Home's PPF

0200400600800100080160240320400Q*bananaQ*apple Foreign's PPF 百度文库 - 让每个人平等地提升自我

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3．Now suppose world relative demand takes the following form: Demand for apples/demand

for bananas = price of bananas/price of apples.

a．Graph the relative demand curve along with the relative supply curve:

abba/PP/DD

∵When the market achieves its equilibrium, we have 1ba)(DDbabbaaPPQQQQ

∴RD is a hyperbola xy1

b．What is the equilibrium relative price of apples?

The equilibrium relative price of apples is determined by the intersection of the RD and RS

curves.

RD: yx1

RS:

5]5,5.1[5.1],5.0(5.0)5.0,0[yyyxxx

∴25.0yx 百度文库 - 让每个人平等地提升自我

6 ∴2/bPaPee

c．Describe the pattern of trade.

∵babeaebaPPPPPP///

∴In this two-country world, Home will specialize in the apple production, export apples

and import bananas. Foreign will specialize in the banana production, export bananas and

import apples.

d．Show that both Home and Foreign gain from trade.

International trade allows Home and Foreign to consume anywhere within the colored

lines, which lie outside the countries’ production possibility frontiers. And the indirect

method, specializing in producing only one production then trade with other country, is a

more efficient method than direct production. In the absence of trade, Home could gain

three bananas by foregoing two apples, and Foreign could gain by one foregoing five

bananas. Trade allows each country to trade two bananas for one apple. Home could then

gain four bananas by foregoing two apples while Foreign could gain one apple by

foregoing only two bananas. So both Home and Foreign gain from trade.

4．Suppose that instead of 1200 workers, Home had 2400. Find the equilibrium relative price.

What can you say about the efficiency of world production and the division of the gains from

trade between Home and Foreign in this case?

RD: yx1 百度文库 - 让每个人平等地提升自我

6 RS:

5]5,5.1[5.1],1(1)1,0[yyyxxx

∴5.132yx

∴5.1/bPaPee

In this case, Foreign will specialize in the banana production, export bananas and import

apples. But Home will produce bananas and apples at the same time. And the opportunity

cost of bananas in terms of apples for Home remains the same. So Home neither gains nor

loses but Foreign gains from trade.

5．Suppose that Home has 2400 workers, but they are only half as production in both

industries as we have been assuming, Construct the world relative supply curve and

determine the equilibrium relative price. How do the gains from trade compare with those in

the case described in problem 4?

In this case, the labor is doubled while the productivity of labor is halved, so the ＂effective

labor＂remains the same. So the answer is similar to that in 3. And both Home and Foreign

can gain from trade. But Foreign gains lesser compare with that in the case 4. 百度文库 - 让每个人平等地提升自我

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6．”Korean workers earn only $ an hour; if we allow Korea to export as much as it likes to

the United States, our workers will be forced down to the same level. You can’t import a $5

shirt without importing the $ wage that goes with it.” Discuss.

In fact, relative wage rate is determined by comparative productivity and the relative demand

for goods. Korea’s low wage reflects the fact that Korea is less productive than the United

States in most industries. Actually, trade with a less productive, low wage country can raise the

welfare and standard of living of countries with high productivity, such as United States. So

this pauper labor argument is wrong.