1. BA 187 – International Trade
Standard Trade Model and Gains from Trade

2. Standard Trade Model Technology Tastes
Two countries produce two goods, X & Y using two factors of production, labor, L and capital, K. (2 x 2 x 2 model)
Prod’n function exhibits constant returns to scale, diminishing marginal returns to a factor.
Economies have different endowments of the factors of prod’n.
Tastes
Economy’s preferences can be represented by community indifference curves.
Assume away distortions like taxes, subsidies, imperfect competition.

3. Technology & Country PPF
PPF: Shape shows diminishing marg. returns to factors of prod’n.
Iso-Value Lines: For given set of relative prices, px, shows prod’n points with equal value.
Perfect Competition: Nation chooses highest iso-value line given its PPF. Y
Iso-value lines
Prod’n Possibilities X

4. Trade and Relative Prices
Begin with country in autarkic equilibrium:
relative price (PX/PY)A & consump/prod’n at point A.
Opening country to trade changes relative price.
Assume Home exports Good X, then new price will be steeper than in autarchy (PX/PY)T > (PX/PY)A.
Home consumes at point C, produces at point Q
Increases prod’n of Good X (which it exports).
Increases consumption of Good Y (which it imports).
As in Classical Model, opening trade leads to gains to both economies. You should be able to show that Foreign will also benefit, using a similar diagram.

5. Effects of Trade on a CountryCH QH
(PX/PY)T
U’H Y UH
Home Imports, CY - QY
Home Exports, QX - CX A
Prod’n Possibilities
(PX/PY)A X

6. % Change in U.S. Employment Resulting from Foreign Trade, 1970-1980
Industry
Percent Change
Footwear
-15.9
Motor Vehicles & equipment
-11.1
Electrical components
-7.8
Leather Products
-6.3
Apparel
Service industry machines
5.7
Misc. machinery
8.0
Aircraft & parts
12.8
Office & computing machines
16.1
Engines & turbines
17.8
Construction machinery
19.9
Source: R.Z. Lawrence, Can America Compete?

7. Sources of Gains from Trade
Can break a country’s gains from trade into two distinct parts.
Gains from Exchange (Consumption Gains)
Assume trade changes the relative price but the country continues to produce at the autarchy equilib. Point A.
Nation still experiences a gain in welfare due to price change measured by move from point A to C1.
Gains from Specialization (Production Gains)
The change in relative price leads the country to change production from Point A to Point Q1.
Nation experiences an additional gain in welfare due to prod’n specialization measured by move from point C1 to C2.
This is similar to the substitution/wealth effect analysis of a price change in microeconomics.

8. Sources of Gains from TradeY C1
(PX/PY)2 Q2
Prod’n Possibilities A1
(PX/PY)1 X

9. Sources of the Basis for Trade

10. The Basis for Trade
Mutual gains from trade arise in the Standard model of trade in essentially two ways:
Differences in Production Possibilities
PPF’s may differ across countries in ways that give rise to trade due to:
Differences in Technology
Differences in Factor Endowments
Differences in Tastes
Utility curves across countries can differ in ways that give rise to trade even when PPF’s are identical.
Illustrate trade possibilities in these two situations

11. Differing Technology/EndowmentsQF QH C*
New equilib. consumption at C*.
Each country has different prod’n ;point.
Assuming identical utility function for Home & Foreign
(PX/PY)*
Opening trade changes relative prices
PPFH
PPFF
Home & Foreign PPF’s differ due to differences in
technology or factor endowments. Y AH AF
Autarky Equilibrium at AH and AF X

12. Differing Utility FunctionsAF UF
Utility curves differ across countries,
autarchy prices differ based on utility. CF
U’F
Each consumes at different point,
both countries gain from trade.
Assuming identical PPF’s for Home & Foreign. Q*
(PX/PY)*
Open trade, equalizes relative prices,
both countries produce at point Q. Y CH
U’H AH UH X

13. Revealed Comparative Advantage Composition of Exports & Imports of the U.S., Europe, and Japan in 1990
U.S.
% of Total
Europe
Japan
Exports
Imports
Commodities
(21.2)
(24.1)
(18.4)
(26.8)
(2.5)
(54.8)
Food
10.8
5.8
10.4
10.7
0.6
14.5
Fuel
3.1
13.3
3.7
8.8
0.4
24.5
Manufactures
(73.9)
(75.5)
(79.7)
(71.0)
(95.9)
(42.6)
Autos
9.0
15.2
11.7
9.2
23.1
Chemicals
10.0
4.6
12.0
5.5
6.5
Telecomm
13.1
12.3
6.1
8.2
23.3
4.8
Textiles
1.9
6.3
6.8
2.2
Source: GATT, International Trade,

14. Determining Trade Equilibrium

15. Trade Equilibrium
In equilibrium, terms of trade adjust to ensure balanced trade between the two countries.
Current account = 0 in Standard Trade Model equilib.
Can illustrate trade equilibrium using diagram of PPF’s and utility curves for the two countries.
Both PPF’s & utility curves differ across countries initially. Autarchy relative prices differ, leading to potential gains from trade.
Trade equalizes relative prices across countries.
In equilibrium, this relative price adjusts to make trade triangles for each country identical, i.e. balanced trade.

16. Determining Trade EquilibriumCF
(PX/PY)* CF
(PX/PY)* QF
(PX/PY)* QH CH
“Trade Triangles” Y AF AH
PPFH
PPFF X

17. Relative Demand & Supply
Alternative, and easier way, to visualize equilibrium terms of trade is to use relative demand and supply.
Relative Demand
Increase in PX/PY, relative price of Good X, results in relative fall in demand for Good X relative to Good Y.
Corresponds to move from C1 to C2 on next slide.
Relative Supply
Increase in PX/PY, relative price of Good X, results in movement along the PPF of each country from Q1 to Q2.
Result is a relative increase in prod’n of Good X relative to Good Y.

18. Deriving Relative Demand & Supply
Relative Price of X
(PX/PY)2 Q2 C2 Y
PX/PY RD RS
PPF C1
(PX/PY)2
(PX/PY)1 Q1
(PX/PY)*
(PX/PY)1 X
Relative Quantity of X
(qX+ q*X)/(qY + q*Y)

19. Terms of Trade for Developing and Developed Countries 1972-1988
Year
1972
1974
1976
1978
1980
1982
1984
1986
1988
Developing Countries
Oil Exporters
100
258
259
248
412
456
206
192
Other 99 94 96 91 84 87 92
Developed Countries 88 89 80 81 90
Terms of Trade = Export Unit Value ÷ Import Unit Value, 1972 = 100
Source: IMF, International Financial Statistics

20. Growth & Trade Equilibrium

21. Economic Growth & Trade
How does economic growth both in our country & in the rest of the world affect trade?
Ambiguity at “common sense” level
Our growth means better able to export to world but
May mean receive lower prices for our exports.
Similar considerations for growth in rest of world.
We look only at effects of growth on trade, particularly a country’s terms-of-trade.
Our economic growth increases our GDP directly but look at whether effect through trade adds or subtracts from this benefit of growth.
Similarly growth in another nation has no direct effect on us but may benefit or hurt us through effect on trade.

22. Growth and a Nation’s PPF
Economic growth shifts out a nation’s PPF.
Trade effects occur because growth often biased, shifts PPF out more in one good than the other.
Export-biased Growth
Growth that expands a nation’s PPF more towards its export good.
Import-biased Growth
Growth that expands a nation’s PPF more towards its import good.

23. Export-Biased Growth and Trade
Relative Price of X Y
PX/PY
PPF1
RS1
RS0
PPF0 Q1
(PX/PY)0
RD0
(PX/PY)1 Q0 X
Relative Quantity of X
(qX+ q*X)/(qY + q*Y)

24. Import-Biased Growth and Trade
Relative Price of X Y
RS1
PX/PY
PPF1 Q1
RS0
PPF0
(PX/PY)1 Q0
(PX/PY)0
RD0 X
Relative Quantity of X
(qX+ q*X)/(qY + q*Y)

25. Economic Growth & Welfare
Export-biased growth tends to worsen a nation’s terms of trade benefiting the rest of the world.
Import-biased growth tends to improve a nation’s terms of trade at the rest of the world’s expense.
Immiserizing Growth
1950’s belief that export-biased growth could worsen terms of trade so much that nation worse off than if had not grown at all.
Requires extreme conditions unlikely to hold in real world (large shift, steep RS & RD curves)

26. Trade Policy & Equilibrium

27. Trade Policy & Equilibrium
Look at effects of three types of gov’t policies on terms of trade equilibrium.
International Income Transfers
Pure income transfers (aid) or short run effects of changes in international lending.
Import Tariffs
Taxes levied on nation’s imports
Export Subsidies
Payments given to domestic producers of export goods.

28. International Income Transfers
Income transfer from Home to Foreign.
Home expenditure falls, Foreign expenditure rises.
Net result for RD depends on differences in marg. prop. to spend on Good X between Home & Foreign.
Transfer shifts RD back if donor has higher mps on its export than recipient.
Donor’s terms of trade worsen.
Relative Price of X
PX/PY
RD1
(PX/PY)1
RS0
(PX/PY)0
RD0
Relative Quantity of X
(qX+ q*X)/(qY + q*Y)

29. Import Tariffs & Terms of Trade
Both tariffs & subsidies drive a wedge between prices of goods internationally (external prices) & domestically (internal prices).
Tariff
Makes imported goods more expensive within a nation than they are outside. This has two effects within nation:
Home producers face lower relative price of Good X & so produce less X and more Y. (RS falls)
Home consumers demand less Y and more X. (RD rises)
Home’s terms of trade improve at expense of Foreign.
Size of effect depends on how large Home is relative to ROW. If country is small then little impact on world RD and RS so correspondingly small effect on terms of trade

30. Effects of a Import Tariff
Relative Price of X
Import tariff decreases internal relative price of export good X vs. good Y.
Internal price of export good X falls.
Home produces less X & more Y (RS shifts in).
Home consumes less X & more Y (RD shifts out).
Terms of trade improve for Home and worsen for Foreign.
PX/PY
RS1
RD1
RS0
(PX/PY)1
(PX/PY)0
RD0
Relative Quantity of X
(qX+ q*X)/(qY + q*Y)

31. Effects of a Export Subsidy
Relative Price of X
Export subsidy has exact opposite effect on internal versus external prices to an import tariff.
Internal price of export good X rises.
Home produces more X & less Y (RS shifts out).
Home consumes less X & more Y (RD shifts in).
Terms of trade worsen for Home and improve for Foreign.
PX/PY
RS0
RS1
RD1
(PX/PY)0
(PX/PY)1
RD0
Relative Quantity of X
(qX+ q*X)/(qY + q*Y)

32. Summary of Policy Effects
International Distribution of Income
Import Tariff
Tariff hurts Rest of World by hurting its terms of trade.
Improves Home’s terms of trade BUT leads to distortion in prod’n & consumption (efficiency losses).
Export Subsidy
Subsidy helps ROW by improving its terms of trade.
Hurts Home’s terms of trade AND leads to distortion in prod’n & consumption (efficiency losses)
In a multi-commodity world:
Export subsidies to goods we import, improve our welfare
Import tariffs on goods we export, hurt our welfare.

33. Alternative Method to Determine Trade Equilibrium

34. Offer Curves and Trade Equilib.
Offer Curve analysis focuses explicitly on a country’s exports and imports at any terms of trade.
Use PPF/Utility function diagram to generate difference between consumption and prod’n for each good at any relative price (its trade triangle at each relative price).
Offer Curve Diagram summarizes these trade triangles with relative price equal to slope of ray from origin.
Can construct an Offer Curve for each country. Point at which they cross is where trade is balanced, i.e. trade triangles are equal.
Can use to analyze effects of growth or trade policy as alternative to relative demand/supply approach.

35. Deriving An Offer Curve
Home Imports, CY – QY Q2
(PX/PY)2 C2
Foreign Exports, Q*Y – C*Y Y
Home Country Offer Curve
(PX/PY)2 C1 Q1
(PX/PY)1
(PX/PY)1
Prod’n Possibilities X
Home Exports, Q*X – C*X
Foreign Imports, C*X – Q*X

36. Offer Curves & Trade Equilibrium
Home Imports, CY – QY
Foreign Exports, Q*Y – C*Y
Home Country Offer Curve
Equilib. Price Ratio, PX /PY X Y
Foreign Country Offer Curve
Home Exports, Q*X – C*X
Foreign Imports, C*X – Q*X

37. Export-Biased Growth and Trade II
Home Imports, CY – QY
Foreign Exports, Q*Y – C*Y
Home Country Offer Curves Y
OC0
OC1
PPF1 C1
PPF0 C0 Q0 Q1
(PX/PY) X
Home Exports, Q*X – C*X
Foreign Imports, C*X – Q*X

38. Export-biased Growth & Trade II
Home Imports, CY – QY
Foreign Exports, Q*Y – C*Y
Home Country OC0
( PX /PY)0
OC1
( PX /PY)1
Foreign Country Offer Curve
Home Exports, Q*X – C*X
Foreign Imports, C*X – Q*X