1. 8 chapter: >> International Trade Krugman/Wells Economics
©2009  Worth Publishers 1

2. How comparative advantage leads to mutually beneficial international trade
The sources of international comparative advantage
Who gains and who loses from international trade, and why the gains exceed the losses
How tariffs and import quotas cause inefficiency and reduce total surplus
Why governments often engage in trade protection to shelter domestic industries from imports and how international trade agreements counteract this

3. Comparative Advantage and International Trade
Goods and services purchased from other countries are imports; goods and services sold to other countries are exports.
Globalization is the phenomenon of growing economic linkages among countries.
To understand why international trade occurs and why economists believe it is beneficial to the economy, we will first review the concept of comparative advantage.
The following graph illustrates the growing importance of international trade…

4. The Growing Importance of International Trade
(a) U.S. Imports and Exports
(b) Imports and Exports for Different Countries, 2005
Percent of GDP
Percent of GDP
90% I
mpo r ts
18% 80 16 70 14 60 12 50 10 40 8 30 6
Figure Caption: Figure 8-1: The Growing Importance of International Trade
Panel (a) illustrates the fact that over the past 40 years, the United States has exported a steadily growing share of its GDP to other countries and imported a growing share of what it consumes from abroad. Panel (b) demonstrates that international trade is significantly more important to many other countries than it is to the United States, with the exception of Japan.
Expo r ts 20 4 2 10
1960
1970
1980
1990
2000
2006
U.S.
Year
China
France
Canada
Mexico
Germany
Belgium

5. Production Possibilities and Comparative Advantage, Revisited
Let’s repeat the definition of comparative advantage from earlier: A country has a comparative advantage in producing a good or service if the opportunity cost of producing the good or service is lower for that country than for other countries.
The Ricardian model of international trade analyzes international trade under the assumption that opportunity costs are constant.
Autarky is a situation in which a country cannot trade with other countries.
The following figure shows hypothetical production possibility frontiers for the U.S. and Colombia and we assume that: there are only two goods and the production possibility frontiers are straight lines.

6. Comparative Advantage and the Production Possibility Frontier
(a) U.S. Production Possibility Frontier
(b) Vietnamese Production Possibility Frontier
Quantity of computers
Quantity of computers
2,000
Slope = –2
U.S. production and consumption in autarky
Vietnamese production and consumption in autarky
Slope = –0.5
1,000 C US
1,000
Figure Caption: Figure 8-2: Comparative Advantage and the Production Possibility Frontier
The U.S. opportunity cost of each ton of shrimp in terms of computers is 2: 2 computers must be forgone for every additional ton of shrimp produced. The Vietnamese opportunity cost of each ton of shrimp in terms of computers is 0.5: only 0.5 computer must be forgone for every additional ton of shrimp produced. So Vietnam has a comparative advantage in shrimp and the United States has a comparative advantage in computers. In autarky, CUS is the U.S. production and consumption bundle and CV is the Vietnamese production and consumption bundle. C V
500
PPF
PPF US V
500
1,000
1,000
2,000
Quantity of shrimp (tons)
Quantity of shrimp (tons)

7. The Gains from International Trade
The Ricardian model of international trade shows that trade between two countries makes both countries better off than they would be in autarky—that is, there are gains from trade.
The following tables and figures illustrate that specialization has the effect of increasing total world production of both goods and that each country can consume more of both goods than it did under autarky.

8. Production and Consumption Under Autarky
(a) United States
Production
Consumption
Quantity of shrimp (tons)
500
Quantity of computers
1,000
(b) Vietnam
(c) World (United States and Vietnam)
1,500

9. Production and Consumption After Specialization and Trade
(a) United States
Production
Consumption
Quantity of shrimp (tons)
750
Quantity of computers
2,000
1,250
(b) Vietnam
(c) World (United States and Vietnam)

10. The Gains from International Trade
(a) U.S. Production and Consumption
(b) Vietnamese Production and Consumption
Quantity of computers
Quantity of computers
Vietnamese production and consumption in autarky Q
U.S. production with trade US
2,000
U.S. consumption with trade
Vietnamese consumption with trade C’ US
1,250 C
PPF US
1,000 V
1,000
U.S. production and consumption in autarky C’
750 V
Vietnamese production with trade C
500 V
Figure Caption: Figure 8-3: The Gains from International Trade
Trade increases world production of both goods, allowing both countries to consume more. Here, each country specializes its production as a result of trade: the United States produces at QUS and Vietnam produces at QV. Total world production of computers has risen from 1,500 to 2,000 and of shrimp from 1,500 tons to 2,000 tons. The United States can now consume bundle C′ US, and Vietnam can now consume bundle C′ V—consumption bundles that were unattainable without trade.
PPF Q U S V
500
750
1,000
1,000
1,250
2,000
Quantity of shrimps (tons)
Quantity of shrimps (tons)

11. Sources of Comparative Advantage
The main sources of comparative advantage are:
International differences in climate
Differences in technology
Factor endowments
The relationship between comparative advantage and factor availability is found in an influential model of international trade, the Heckscher–Ohlin model.

12. Heckscher-Ohlin Model
According to the Heckscher-Ohlin model, a country has a comparative advantage in a good whose production is intensive in the factors that are abundantly available in that country.
A key concept in the model is factor intensity.
The factor intensity of production of a good is a measure of which factor is used in relatively greater quantities than other factors in production. Oil refining is capital-intensive compared to clothing manufacture, because oil refiners use a higher ratio of capital to labor than clothing producers.

13. Heckscher-Ohlin Model
The Heckscher–Ohlin model shows how comparative advantage can arise from differences in factory endowments: goods differ in their factor intensity, and countries tend to export goods that are intensive in the factors they have in abundance.
Trade in manufactured goods amongst developed countries is best explained by increasing returns to production.

14. Supply, Demand, and International Trade
The Effects of Imports
The domestic demand curve shows how the quantity of a good demanded by domestic consumers depends on the price of that good.
The domestic supply curve shows how the quantity of a good supplied by domestic producers depends on the price of that good.
The world price of a good is the price at which that good can be bought or sold abroad.

15. The Effects of Imports
When a market is opened to trade, competition among importers or exporters drives the domestic price to equality with the world price.
If the world price is lower than the autarky price, trade leads to imports and a fall in the domestic price compared to the world price.
There are overall gains from trade because consumer gains exceed the producer losses.

16. Education, Skill Intensity, and Trade
The upward slope of the yellow curve illustrates the fact that as a German industry grows more skill intensive, its share of exports to the United States also grows.
In contrast, the downward slope of the brown curve shows that as a Bangladeshi industry grows less skill-intensive, its share of exports to the United States rises.
Share of U.S. imports from Germany, by industry
Share of U.S. imports from Bangladesh, by industry
12%
0.4%
Germany (left scale) 10
0.3 8 6
0.2
Figure Caption: Figure 8-4: Education, Skill Intensity, and Trade
In this graph, increasing skill intensity is measured by moving from left to right along the horizontal axis. The vertical axes measure the share of exports from a given industry to the United States, with Germany on the left axis and Bangladesh on the right. The upward slope of the yellow curve illustrates the fact that as a German industry grows more skill intensive, its share of exports to the United States also grows. In contrast, the downward slope of the brown curve shows that as a Bangladeshi industry grows less skill-intensive, its share of exports to the United States rises.
Bangladesh (right scale) 4
0.1 2
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
Skill intensity of industry

17. Consumer and Producer Surplus in Autarky
Price of shrimp
Domestic supply
Consumer surplus A P A
Producer surplus
Domestic demand
Figure Caption: Figure 8-5: Consumer and Producer Surplus in Autarky Consumer and Producer Surplus in Autarky
In the absence of trade, domestic price is PA, the autarky price at which the domestic supply curve and the domestic demand curve intersect. The quantity produced and consumed domestically is QA. Consumer surplus is represented by the blue-shaded area, and producer surplus is represented by the red-shaded area. Q
Quantity of Shrimp A
Consumer surplus is represented by the blue-shaded area.
Producer surplus is represented by the red-shaded area.

18. The Domestic Market with Imports
Price of computer
Domestic supply
World price P W A P A
Autarky price
Domestic demand
Figure Caption: Figure 8-6: The Domestic Market with Imports
Here the world price of shrimp, PW, is below the autarky price, PA. When the economy is opened to international trade, imports enter the domestic market, and the domestic price falls from the autarky price, PA, to the world price, PW. As the price falls, the domestic quantity demanded rises from QA to QD and the domestic quantity supplied falls from QA to QS. The difference between domestic quantity demanded and domestic quantity supplied at PW, the quantity QD−QS, is filled by imports. Q Q Q
Domestic quantity demanded with trade D A S
Domestic quantity supplied with trade
Quantity of computers
Exports

19. The Effects of Imports on Surplus
Changes in surplus
Price of computer
Gain
Loss
Consumer surplus – X
Domestic supply
Producer surplus X + Z W
Change in total surplus P
+ Z W Z X P A A Y
Domestic demand
Figure Caption: Figure 8-7: The Effects of Imports on Surplus
When the domestic price falls to PW as a result of international trade, consumers gain additional surplus (areas X+Z) and producers lose surplus (area X). Because the gains to consumers outweigh the losses to producers, there is an increase in the total surplus in the economy as a whole (area Z). Q Q Q D A S
Quantity of computers
Exports

20. The Effects of Exports
If the world price is higher than the autarky price, trade leads to exports and a rise in the domestic price compared to the world price.
There are overall gains from trade because producer gains exceed the consumer losses.
The graph that follows shows the domestic market with exports.

21. The Domestic Market with Exports
Price of computer
Domestic supply
World price P W A P A
Autarky price
Domestic demand
Figure Caption: Figure 8-8: The Domestic Market with Exports
Here the world price, PW, is greater than the autarky price, PA. When the economy is opened to international trade, some of the domestic supply is now exported. The domestic price rises from the autarky price, PA, to the world price, PW. As the price rises, the domestic quantity demanded falls from QA to QD and the domestic quantity supplied rises from QA to QS. The portion of domestic production that is not consumed domestically, Q−Q, is exported. Q Q Q
Domestic quantity demanded with trade D A S
Domestic quantity supplied with trade
Quantity of computers
Exports

22. The Effects of Exports on Surplus
Changes in surplus
Price of computer
Gain
Loss
Consumer surplus – X
Domestic supply
Producer surplus X + Z W
Change in total surplus P
+ Z W Z X P A A Y
Domestic demand
Figure Caption: Figure 8-9: The Effects of Exports on Surplus
When the domestic price rises to PW as a result of trade, producers gain additional surplus (areas X+Z) but consumers lose surplus (area X). Because the gains to producers outweigh the losses to consumers, there is an increase in the total surplus in the economy as a whole (area Z). Q Q Q D A S
Quantity of computers
Exports

23. International Trade and Wages
Exporting industries produce goods and services that are sold abroad.
Import-competing industries produce goods and services that are also imported.
International trade tends to increase the demand for factors that are abundant in our country compared with other countries, and to decrease the demand for factors that are scarce in our country compared with other countries.

24. Effects of Trade Protection
An economy has free trade when the government does not attempt either to reduce or to increase the levels of exports and imports that occur naturally as a result of supply and demand. Policies that limit imports are known as trade protection or simply as protection.
Most economists advocate free trade, although many governments engage in trade protection of import-competing industries. The two most common protectionist policies are tariffs and import quotas. In rare instances, governments subsidize export industries.

25. Effects of a Tariff A tariff is a tax levied on imports.
It raises the domestic price above the world price, leading to a fall in trade and total consumption and a rise in domestic production.
Domestic producers and the government gain, but consumer losses more than offset this gain, leading to deadweight loss in total surplus.

26. The Effect of a Tariff Price of shrimp Domestic supply
Price with tariff P T
Tariff P W
Domestic demand
Figure Caption: Figure 8-10: The Effect of a Tariff
A tariff raises the domestic price of the good from PW to PT. The domestic quantity demanded shrinks from QD to QDT, and the domestic quantity supplied increases from QS to QST. As a result, imports—which had been QD− QS before the tariff was imposed—shrink to Q−Q after the tariff is imposed.
World price Q Q Q Q
Quantity of Shrimp S ST D T D
Imports after tariff
Imports before tariff

27. A Tariff Reduces Total Surplus
Changes in surplus
Price of shrimp
Gain
Loss
Domestic supply
Consumer surplus –( A + ) + B C D
Producer surplus A
Government revenue C
Change in total surplus P T –( B + D )
Tariff A B C D P W
Domestic demand
Figure Caption: Figure 8-11: A Tariff Reduces Total Surplus
When the domestic price rises as a result of a tariff, producers gain additional surplus (area A), the government gains revenue (area C), and consumers lose surplus (areas A+B+C+D). Because the losses to consumers outweigh the gains to producers and the government, the economy as a whole loses surplus (areas B+D). Q Q Q Q S ST D T D
Quantity of Shrimp
Imports after tariff
Imports before tariff

28. Effects of an Import Quota
An import quota is a legal limit on the quantity of a good that can be imported.
Its effect is like that of a tariff, except that revenues—the quota rents—accrue to the license-holder, not to the government.
Now, let’s move on to the political economy of trade protection…

29. The Political Economy of Trade Protection
Arguments for Trade Protection
Advocates of tariffs and import quotas offer a variety of arguments. Three common arguments are:
national security
job creation
the infant industry argument
Despite the deadweight losses, import protections are often imposed because groups representing import-competing industries are smaller and more cohesive than groups of consumers.

30. International Trade Agreements and the World Trade Organization
To further trade liberalization, countries engage in international trade agreements.
International trade agreements are treaties in which a country promises to engage in less trade protection against the exports of other countries in return for a promise by other countries to do the same for its own exports.
Some agreements are for only a small number of countries, such as the North American Free Trade Agreement which is among the United States, Canada and Mexico.

31. International Trade Agreements and the World Trade Organization
The World Trade Organization (WTO) is a multinational organization that seeks to negotiate global trade agreements as well as adjudicate trade disputes between member countries.
The European Union, or EU, is a customs union among 27 European nations.

32. New Challenges to Globalization
There are two concerns shared by economists:
Worries about the effects of globalization on inequality.
Worries that new developments, in particular the growth in offshore outsourcing, are increasing economic insecurity.
Offshore outsourcing takes place when businesses hire people in another country to perform various tasks.

33. International trade is of growing importance to the United States and of even greater importance to most other countries. Foreign trade has been growing rapidly, a phenomenon called globalization.
The Ricardian model of international trade assumes that opportunity costs are constant. It shows that there are gains from trade: two countries are better off with trade than in autarky.
The Heckscher–Ohlin model shows how differences in factor endowments determine comparative advantage.

34. The domestic demand curve and the domestic supply curve determine the price of a good in autarky. When international trade occurs, the domestic price is driven to equality with the world price, the price at which the good is bought and sold abroad.
If the world price is below the autarky price, a good is imported. This leads to an increase in consumer surplus, a fall in producer surplus, and a gain in total surplus. If the world price is above the autarky price, a good is exported. This leads to an increase in producer surplus, a fall in consumer surplus, and a gain in total surplus.
International trade leads to expansion in exporting industries and contraction in import-competing industries.

35. Most economists advocate free trade, but in practice many governments engage in trade protection.
A tariff is a tax levied on imports. An import quota is a legal limit on the quantity of a good that can be imported.
Although several popular arguments have been made in favor of trade protection, in practice the main reason for protection is probably political: import-competing industries are well-organized and well-informed about how they gain from trade protection, while consumers are unaware of the costs they pay.
Many concerns have been raised about the effects of globalization.