1. The Power of Trade and Comparative Advantage
Chapter 2
The Power of Trade and Comparative Advantage

2. Outline Trade and Preferences
Specialization, Productivity, and the Division of Knowledge
Comparative Advantage
Trade and Globalization

3. Discussion Question
Think of the last time you bought or sold something. Why did you make the trade?
Answer: You probably traded because you preferred what you got over what you gave up. For example, if you bought a candy bar for $1, you probably preferred the candy bar to having $1 in your pocket.

4. Trade and Preferences eBay profits by making buyers and sellers happy
Selling a broken laser pointer on EBay (1995)
Offered at $1 and sold for $14.83 to a collector of broken laser points
One man’s junk is another man’s treasure
eBay profits by making buyers and sellers happy

5. Tyler Cowen and Alex Tabarrok
eBay profits by making buyers and sellers happy.
RICH HOXSEY
Tyler Cowen and Alex Tabarrok
Modern Principles: Macroeconomics, Third Edition / Modern Principles of Economics, Third Edition Copyright © 2015 by Worth Publishers

6. Introduction Benefits of Trade
Trade makes people better off when preferences differ.
Trade increases productivity through specialization and the division of knowledge.
Trade increases productivity through comparative advantage.

7. Trade and Preferences Trade Creates Value
Trade moves goods from people who value them less to people who value them more.
Trade makes people with different preferences better off.

8. Specialization Trade Allows Specialization
With no trade, there is no specialization.
People will specialize in the production of a single good only when they can trade for other goods.

9. Specialization Increased Productivity
We can produce more through trade than by individual production.
People who specialize have more knowledge about their field.
Because they sell large quantities, people who specialize can take advantage of large-scale equipment.

10. Specialization Division of Knowledge
Without specialization, each person produces their own food, clothing, and so on.
Each person has the same knowledge as everybody else.
The combined knowledge of a society is not much more than that of a single person.

11. Tyler Cowen and Alex Tabarrok
Contra episode 56, even Spock’s brain could not come close to running a modern economy; the work needed to do that would have to be spread across millions of brains. For this reason, some economists consider “Spock’s Brain” to be the worst Star Trek episode ever.
THE KOBAL COLLECTION AT ART RESOURCE, NY
Tyler Cowen and Alex Tabarrok
Modern Principles: Macroeconomics, Third Edition / Modern Principles of Economics, Third Edition Copyright © 2015 by Worth Publishers

12. Specialization Division of Knowledge
With specialization, much more knowledge is used than could exist in a single brain.
Knowledge increases productivity so specialization increases total output.
Every increase in world trade is an opportunity to increase the division of knowledge.
When everyone knows something different, the combined brain power of society is huge

13. Reducing Trade Barriers, Berlin 1989
DAVID BRAUCHLI/REUTERS/LANDOV
Tyler Cowen and Alex Tabarrok
Modern Principles: Macroeconomics, Third Edition / Modern Principles of Economics, Third Edition Copyright © 2015 by Worth Publishers

14. Self-Check One of the benefits of specialization is: Less pollution.
More equality.
Increased productivity.
Answer: c – increased productivity.

15. Definition Production Possibilities Frontier:
Shows all the combinations of goods that a country can produce given its productivity and supply of inputs.

16. Production Possibilities Frontier
PPF is a very simplified and abstract model representing production and trade
PPF exists for a given country at a given point in time
PPF can be used to demonstrate:
Scarcity
Tradeoffs (opportunity costs)
Efficiency (unemployment of resources)
Economic growth
Figure 2-1 (2-1): Production and Consumption in Mexico and the United States without Trade
Tyler Cowen and Alex Tabarrok
Modern Principles: Macroeconomics, Third Edition / Modern Principles of Economics, Third Edition Copyright © 2015 by Worth Publishers

17. Production Possibilities Frontier
Assume that we have a two-country, two-good economic model
The table shows the labor (resource) required to produce each good for each economy
The PPF
Figure 2-1 (2-1): Production and Consumption in Mexico and the United States without Trade
Tyler Cowen and Alex Tabarrok
Modern Principles: Macroeconomics, Third Edition / Modern Principles of Economics, Third Edition Copyright © 2015 by Worth Publishers

18. Production Possibilities Frontier
The PPF for each economy based on the output table
Assuming that each economy has 24 units of labor as a resource, the PPF shows all the possible combinations of production for each country
The midpoint on each PPF represents equal division of labor between the two products (no trade occurring)
Figure 2-1 (2-1): Production and Consumption in Mexico and the United States without Trade
Tyler Cowen and Alex Tabarrok
Modern Principles: Macroeconomics, Third Edition / Modern Principles of Economics, Third Edition Copyright © 2015 by Worth Publishers

19. Production – Resource Inputs
Units of Labor
Country
Computers
Shirts
Mexico 12 2
U.S. 1
The U.S. can produce both computers and shirts at lower cost (less labor).
The U.S. has an absolute advantage in the production of both goods.

20. Definition Absolute advantage:
The ability to produce the same good using fewer inputs than another producer.

21. Production Possibilities Frontier
Figure 2-1 (2-1): Production and Consumption in Mexico and the United States without Trade
Tyler Cowen and Alex Tabarrok
Modern Principles: Macroeconomics, Third Edition / Modern Principles of Economics, Third Edition Copyright © 2015 by Worth Publishers

22. Martha Stewart: Writing Books vs Ironing
Comparative advantage: It’s a good thing.
AMANDA EDWARDS/GETTY IMAGES
Tyler Cowen and Alex Tabarrok
Modern Principles: Macroeconomics, Third Edition / Modern Principles of Economics, Third Edition Copyright © 2015 by Worth Publishers

23. Comparative Advantage
Absolute and Comparative Advantage
Another reason to trade is to take advantage of differences.
Countries have different climates, levels of human capital, and so on.
Different countries are therefore suited to produce different goods.

24. Definition Comparative advantage:
Producing goods at the lowest opportunity cost.

25. Opportunity Costs and the PPF
PPF illustrates the trade-offs or opportunity costs of producing more of one good by giving up the production of the other good. i.e. What is the cost of changing the mix of production for a given country?

26. Comparative Advantage
Units of Labor
Country
Computers
Shirts
Mexico 12 2
U.S. 1
Assuming each country has 24 units of labor:
Production Possibilities
Country
Computers
Shirts
Mexico 2 12
U.S. 24 OR

27. Comparative Advantage
Units of Labor
Country
Computers
Shirts
Mexico 12 2
U.S. 1
Production Possibilities
Country
Computers
Shirts
Mexico 2 12
U.S. 24

28. Comparative Advantage
Production Possibilities
Country
Computers
Shirts
Mexico 2 12
U.S. 24
With no trade, each country will produce some of each good.
The opportunity cost of a good is the amount of the other good that is given up.

29. Comparative Advantage
Production Possibilities
Country
Computers
Shirts
Mexico 2 12
U.S. 24
In Mexico, 1 computer will cost 6 shirts, while 1 shirt will cost 1/6 of a computer.
In the U.S., 1 computer will cost 1 shirt, and 1 shirt will cost 1 computer.

30. Comparative Advantage
Opportunity Cost
Country
1 Computer
1 Shirt
Mexico
6 shirts
1/6 computer
U.S.
1 shirt
1 computer
Mexico has a comparative advantage (lowest opportunity cost) in shirts.
U.S. has a comparative advantage (lowest opportunity cost) in computers.

31. Self-Check
If country A is able to produce furniture at a lower cost than country B, we would say that country A has a(n):
Absolute advantage.
Comparative advantage.
No advantage.
Answer: a – absolute advantage means producing a good with fewer inputs (lower cost).

32. Comparative Advantage
Absolute and Comparative Advantage
To benefit from trade, a country doesn’t need to have an absolute advantage.
A country can benefit from trade if it has a comparative advantage.
Comparative advantage can be illustrated with a production possibilities frontier.

33. Trade Increases Productivity
If each country produces some of each good and only consumes what it produces:
Production Possibilities (no trade)
Country
Computers
Shirts
Mexico 1 6
U.S. 12
TOTAL: 13 18

34. Trade Increases Productivity
If each country specializes and trades, there is more of everything:
Production Possibilities (before trade)
Country
Computers
Shirts
Mexico 12
U.S. 14 10
TOTAL: 22

35. Trade Increases Productivity
If each country specializes and trades, there is more of everything (Mexico is giving 3 shirts for 1 computer):
Production Possibilities (after trade)
Country
Computers
Shirts
Mexico 1 9
U.S. 13
TOTAL: 14 22

36. Trade Increases Productivity
Figure 2-2 (2-2): Production and Consumption in Mexico and the United States with Trade

37. Comparative Advantage
Comparative Advantage and Wages
Differences in wages reflect differences in productivity.
Wages will be higher in high-productivity countries than in low-productivity countries.
Trade raises wages to the highest levels allowed by a country’s productivity.

38. Trade and Globalization
Globalization and Wages
Wages will rise in high-demand industries and fall in low-demand industries.
Workers will move from low-wage industries to high-wage industries until wages equalize.
The transition isn’t always quick or easy.

39. Trade and Globalization
More on Globalization and Wages
While trade will improve worker’s standard of living, domestic wages are determined by labor productivity
Simply increasing wages by government dictate will not make workers better off unless there is, somehow, an increase in productivity and output,
i.e. raising wages will likely result in inflation

40. Trade and Globalization
“Tariffs and import quotas usually reduce the general welfare of a society.”
% of American Economics Association members
Agree 92%
Disagree 6%
“The U.S. should eliminate remaining tariffs and other barriers to trade.”
% of AEA members
Agree 88%
Disagree 8%

41. Example 1
Erin has a choice between two activities: She can repair one transmission per hour or she can repair two fuel injectors per hour. What is the opportunity cost of repairing one fuel injector?
1 transmission
½ transmission
2 transmissions

42. Example 2
Deirdre has a choice between writing one more book this year or five more articles this year. What is the opportunity cost of writing half of a book this year, in terms of articles?
1/5 article
1 article
2.5 articles
10 articles

43. Example 3
Which country has the absolute advantage in producing high-quality cars? Low-quality cars?
North has absolute advantage in both
South has absolute advantage in both
North: high-quality, South: low-quality
South: high-quality, North: low-quality

44. Example 4
What is the opportunity cost of each high-quality car (HQ) in the South?
½ of a low-quality (LQ) car
1 LQ car
2 LQ cars
1.5 LQ cars

45. Example 5
What is the opportunity cost of each high-quality car (HQ) in the NORTH?
½ of a low-quality (LQ) car
1 LQ car
2 LQ cars
1.5 LQ cars

46. Takeaway
Trade makes people better off when preferences differ.
With specialization and trade, the total sum of knowledge used in an economy increases tremendously.
A country can increase its standard of living by specializing in what it can make at low (opportunity) cost and trading.
"When goods don't cross borders, armies will.“ - attributed incorrectly to Frederic Bastiat, but it sounds a lot like Bastiat