Introduction
The Heckscher-Ohlin (HO hereafter) model was first conceived by two Swedish economists, Eli Heckscher (1919) and Bertil Ohlin. Rudimentary concepts were further developed and added later by Paul Samuelson and Ronald Jones among others. There are four major components of the HO model:
Eli Heckscher (1879 - 1952)
Heckscher was a Swedish economist. He is probably best known for his book "Mercantilist." Although his major interest was in studying economic history, he also developed the essentials of the factor endowment theory of international trade in a short article in Swedish in 1919. It was translated into English thirty years later.
Bertil Ohlin (1899-1979)
Heckscher's student, Bertil Ohlin developed and elaborated the factor endowment theory. He was not only a professor of economics at Stockholm, but also a major political figure in Sweden. He served in Riksdag (Swedish Parliament), was the head of liberal party for almost a 1/4 of a century. He was Minister of Trade during World War II. In 1979 Ohlin was awarded a Nobel prize jointly with James Meade for his work in international trade theory.
HO Model = 2 × 2 × 2 model (2 countries, 2 commodities, 2 factors)
For example, there are two countries (America and Britain); each country is endowed with 2 homogeneous factors (labor and capital) and produces 2 commodities.
This is the smallest case of "even" model, i.e., the number of commodities is equal to that of factors. Extending the model to a more general case is not easy. In fact, the results obtained from a more general model do not have the clear, common sense interpretations which the simple HO model enjoys.
Of course, the assumptions are somewhat unrealistic in the sense that they are not likely to be observed in the real world. However, even if some of the assumptions are violated, international trade has a tendency to equalize factor prices; it will remove the wage gaps between countries, despite the constraint that trading countries impose on the movement of factors, in particular, on the movement of workers.


Transportation costs are assumed to be zero.
In reality, transportation costs are a significant portion of the marketing costs of most traded goods, especially in agricultural products.
Remark: This is unrealistic. However, it is not a bad assumption, because transportation costs inhibit and reduce trade volume; it does not reverse the trade pattern between the countries.
PC prevails in both product and factor markets. This assumption rules out monopolistic and oligopolistic market structures. It also rules out price and wage rigidities. In a perfectly competitive market all buyers and sellers are price takers, i.e., each one is too small to exert market power and influence market prices. All factors are fully employed.
Like Ricardo, HO model draws a sharp distinction between domestic and external factor mobility. The maximum degree of factor mobility is permitted between industries within the same country (domestic factor mobility). But neither capital nor labor can cross national borders (international factor immobility).
DFM insures that workers move from a low wage region to a high wage region, and capital moves from a low interest country to a high interest region. The net effect is that all factor prices are the same within a country.
IFI implies that Mexican workers are not allowed to work or migrate to the US.
Neither country specializes in one commodity. After the introduction of free trade, neither country specializes in one commodity, as in Ricardian model. Each country produces both goods.
Such a production function is sometimes said to be homogeneous of degree 1 - HD(1) for short here.
CRS means that a proportionate increase in all inputs increases the output by the same percentage.
Specifically, CRS means:
If y = F(L,K), then y' = F(2L,2K) = 2y.
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Along the expansion path k, output increases at a constant rate as the amounts of inputs increase. |
Production functions are the same in
America and Britain. The HO model is a long run model. Ohlin argued that
"the physical conditions of production are everywhere the same." Some countries
may be slow to adopt new technology. With the development of modern telecommunications,
information travels fast. The is a result of declining transportation
and communication costs.

Remark: The implication of (1) and (2) is that commodity trade equalizes
commodity prices between countries. That is, Americans and Britons pay the
same prices for same commodities.
Will commodity price equalization result in factor price equalization?

A unit value isoquant is a locus of input combinations that yield $1 worth of output.
(1) Among many isoquants choose the one for which p*2y2 = 1, or y2 = 1/p*2.
(2) Different production functions yield different isoquants:
Two different UVIs intersect each other.
In Figure 2, industry 2 is more capital intensive than industry 1.
If factors are not chosen optimally, production costs will be higher unnecessarily.
(3) Choose y2, L2, and K2 to
maximize Π = p*2y2 - wL2 - rK2
subject to y2 = F2(L2,K2).
Once the desired output is chosen, the cost must be minimized. The equilibrium condition is:
MRTS = w/r
Figure 3, Implication of cost minimization

(4) "No specialization" implies that a common isocost curve must be tangent
to both unit value isoquants. Suppose not.
Figure 4
Arbitrary factor prices (w,r) results in specialization in one commodity.
An arbitrary pair of factor prices (w,r) cannot prevail, because it causes the economy to specialize in one good. For instance, given the factor prices represented by the slopes of the two isocost curves, industry 2 survives at point A (p2y2 = c2) The tangency points (both A and B) yield exactly $1 revenue. But the production costs at points 1 and 2 will differ. For example, C1 > C2 = 1. Thus, firms will produce only commodity 2, which costs less but yields the same revenue. That is, the country specializes in good 2 in the above example.
Thus, for a given pair of output prices (p1,p2), there exists a unique pair of factor prices (w,r). This implies that a pair of output prices completely determines a pair of factor prices. Within a country, (p*1,p*2) <=> (w,r).
Figure 5, Common Isocost Curve

Factor Price Equalization TheoremGiven assumptions 1 - 8, factor prices will be equalized between countries. That is,w = w*, r = r*. |
An ironing woman, Edgar Degas. How will her wage be affected by free trade?
w = p1MPL1 = P2MPL2
r = p1MPK1 = P2MPK2
w/r = MPL1/MPK1 = MRTS1 = the slope of UVI: y1 = 1/p1.
= MPL2/MPK2 = MRTS2 = the slope of UVI: y2 = 1/p2.
Thus, in the Home country, a common isocost curve is tangent to both UVIs.
r* = p*1MP*K1 = p*2MP*K2
p*1 = p1 and p*2 = p2. (Free trade implies output price equalization)
Thus, w* = p*1MP*L1 = p1MP*L1. But will marginal products of labor in any industry be the same in the two countries?
(k1 = k*1, k2 = k*2).
Marginal product of each input depends on the amounts of K and L. However, for CRS industries, MPL and MPK are constant along the expansion path of each industry. The following diagram illustrates MPL maintains constant height along the expansion curve Ok2.
Figure 6. Effects of CRS on marginal products.
MP*Li = MPLi, MP*Ki = MPKi.
r* = p*i MP*Ki = piMPKi = r. (interest rate equalization)
1. It could mean that the Heckscher-Ohlin model does not apply to all trade patterns. It applies to industries in which factor proportions are important, e.g., agriculture and manufacture.
2. In practice, transportation costs are not negligible. Free trade does not equalize output prices or wipe out factor price differentials completely, but will reduce the gap in factor prices between countries.
3. Capital is more mobile than labor. If FPE does not hold, both factors have incentives to move across national boundaries. If stringent restrictions are imposed on migration, it is the capital that will move in search of lower labor costs. This means outsourcing and a huge job loss in high wage countries. Capital mobility further reinforces the effect of free trade to equalize factor prices.
Convergence of Long run Income
National income is written as wL+ rK.
wL + rK = (w + rK/L)L = (w + rS/L)L.
Since w and r are equalized in the world market, there are two elements that determine long run national income.
Population or labor force (L) and the savings rate (S/L).
Per capita income is (w+rS/L).
Beyond a certain threshold level of income, per capita savings rate is a decreasing function of per capita income or wage. For example, China's household savings rate is over 20%, but it is expected to decline. Due to its high savings rate, China was able to maintain the growth rate of 9% over the last 25 years. As the savings rate declines with the rise in per capita income, per capita income approaches a limit that is attained by high income. Eventually, in a stationary state, a nation's economic power is measured by its population. In the short run, its wage also matters. However, population growth also stops once the wage reaches a threshold level.
Business Week, September 1, 2003, page 44.
At first glance, IBM's computer disk drive factory in Szekesfehervar, Hungary, doesn't look the picture of industrial decline. Built just eight years ago, its bright facade still glows from a hillside overlooking a bustling shopping plaza. But a closer look reveals an unnatural stillness. Loading docks that once were piled high with components lie empty. Turnstiles that admitted 3,700 workers a day are chained.
IBM shut the plant last November, moving the work to China, where wages are
75% cheaper. Dutch electronics maker Royal Philips Electronics and Singapore
contract manufacturer Flextronics International Ltd. hae moved an addional 1,500
Hungarian jobs to China in the past 18 months. Flextronics also has closed a
1,000-worker plant in the Czech Republic. The closings are sending shudders
across eight formerly communist countries just as they are gearing up to celebrate
their entry into the European Union on May 1.
...
The labor markets of Asia, especially China, are beginning to pull away industrial
investments that helped this region rebuild after communism's collapse. "Their
whole goal has been to join the EU," says Humphrey W. Porter, president
of Flextronics Europe. "The risk is that they don't realize this is a rat
race. And it's just the beginning, not the end."
...
But Eastern Europe's cost advantage is shrinking by the day. In the past two
years, real wages have risen by 20% in Hungary and 11.5% in the Czech Republic,
according to Vienna-based Erste Bank. Despite the runup, wages in Eastern Europe's
most dynamic economies are still 25% lower than those in Western Europe. But
the gap is widening with China, where wages have stayed at about $100 per month
for unskilled factory workers. Even Eastern European companies, such as Hungary's
Karsai Plastics Holding, are opening plants in China.