1. The Heckscher-Ohlin-Samuelson Theorem
ECN 3860
International Economics
Dr. Ali Moshtagh

2. The Classical and Neo-Classical Models of International Trade
The Classical model of international trade is based on the “Labor Theory of Value”; it assumes only one factor of production, identical technology between the two countries, identical tastes, etc.. The model promotes specialization and requires complete specialization for at least one country, due to constant opportunity costs.
Given a concave production possibilities frontier, international trade should lead to incomplete specialization, due to increasing costs.
The Neo-Classical models of international trade assume more than one factor of production. The Heckscher-Ohlin-Samuelson model (also known as the Factor Endowment or the Variable Proportion Model) not only describes the pattern of trade, but it also predicts the impact of trade on the national income and returns to the factors of production.

3. Other Assumptions: two countries, two factors, two products;
perfect competition in all markets;
Free trade;
Factors of production are available in fixed amounts in each country;
Full mobility of factors of production between industries within each country;
Immobility of factors of production between countries;
The two countries are alike with respect to tastes;
Technology is available to both countries; and
Linear homogeneous production functions of degree one (constant returns to scale).

4. The Heckscher-Ohlin Theorem
Critical Assumptions:
Countries are characterized by different factor endowments--a country is capital abundant if it has a higher ratio of capital to other factors than does its trading partner;
There are different factor intensities between products--a product is capital-intensive if, at identical wages and rents, its production requires more capital per worker than does the other product.

5. The H-O Theorem
Given identical production functions but different factor endowments between countries, a country will tend to export the commodity which is relatively intensive in her relatively abundant factor
In general, countries tend to have comparative advantage in the products that are relatively intensive in their relatively abundant factors

6. The Stolper-Samuelson Theorem:
Assumptions:
One country produces two goods (wheat and cloth) with two factors of production (capital and labor);
neither good is an input into the production of the other;
competition prevails;
factor supplies are given;
both factors are fully employed;
both factors are mobile between sectors (but not between countries);
one good (wheat) is capital-intensive and the other (cloth) is labor-intensive);
opening trade raises the relative price of the export good.

7. The Stolper-Samuelson Theorem
moving from no trade to free trade raises the returns to the factor used intensively in the rising-price industry, and lowers the returns to the factor used intensively in the falling-price industry, regardless of which goods the sellers of the two factors prefer to consume

8. The Factor Price Equalization Theorem
Assumptions:
there are two countries using two factors of production producing two products;
competition prevails in all markets;
each factor supply is fixed, and there is no migration between countries;
each factor is fully employed in each country with or without trade;
there are no transportation or information costs;
free trade;
production functions exhibit constant returns to scale, and are the same between countries for any industry;
production functions are not subject to factor intensity reversals; and
both countries produce both products with or without trade.

9. The Factor Price Equalization Theorem
Free trade will equalize not only commodity prices but also factor prices, so that all workers earn the same wage rate and all units of capital will earn the same rental return in both countries regardless of the factor supplies or the demand patterns in the two countries

10. Hourly Pay in Manufacturing

11. The Leontief Paradox
In 1953 Wassily Leontief published the results of the most famous empirical investigations in economics, an attempt to test the consistency of the H-O Model with the U.S. trade patterns.
Leontief’s objectives were:
to prove that the H-O Model was correct; and
to show that the U.S. exports were capital intensive
Leontief developed a 1947 input-output table for the U.S. to determine the capital-labor ratios used in the production of U.S. exports and imports. Leontief found that the U.S. exports used a capital-labor ratio of $13,991 per man year, whereas import substitutes used a ratio of $18,184 per man year.

12. The Leontief Paradox (13,991 / 1) / (18,184 / 1) = 0.77
The key ratio of [( KX / LX ) / ( KM / LM )]
(13,991 / 1) / (18,184 / 1) = 0.77
was calculated. Given the presumption that the U.S. was relatively capital abundant, that ratio was just the reverse of what the H-O Model predicted. Thus, it is called the Leontief Paradox.