Comparative advantage

In economics, the law of comparative advantage says that two countries (or other kinds of parties, such as individuals or firms) can both gain from trade if, in the absence of trade, they have different relative costs for producing the same goods. Even if one country is more efficient in the production of all goods (absolute advantage), it can still gain by trading with a less-efficient country, as long as they have different relative efficiencies.[
For example, if, using machinery, a worker in one country can produce both shoes and shirts at 6 per hour, and a worker in a country with less machinery can produce either 2 shoes or 4 shirts in an hour, each country can gain from trade because their internal trade-offs between shoes and shirts are different. The less-efficient country has a comparative advantage in shirts, so it finds it more efficient to produce shirts and trade them to the more-efficient country for shoes. Without trade, its cost per shoe was 2 shirts; by trading, its cost per shoe can reduce to as low as 1 shirt depending on how much trade occurs (since the more-efficient country has a 1:1 trade-off). The more-efficient country has a comparative advantage in shoes, so it can gain in efficiency by moving some workers from shirt-production to shoe-production and trading some shoes for shirts. Without trade, its cost to make a shirt was 1 shoe; by trading, its cost per shirt can go as low as 1/2 shoe depending on how much trade occurs.
The net benefits to each country are called the gains from trade.

Origins of the theory

Comparative advantage was first described by David Ricardo who explained it in his 1817 book On the Principles of Political Economy and Taxation in an example involving England and Portugal.[4] In Portugal it is possible to produce both wine and cloth with less labor than it would take to produce the same quantities in England. However the relative costs of producing those two goods are different in the two countries. In England it is very hard to produce wine, and only moderately difficult to produce cloth. In Portugal both are easy to produce. Therefore while it is cheaper to produce cloth in Portugal than England, it is cheaper still for Portugal to produce excess wine, and trade that for English cloth. Conversely England benefits from this trade because its cost for producing cloth has not changed but it can now get wine at a lower price, closer to the cost of cloth. The conclusion drawn is that each country can gain by specializing in the good where it has comparative advantage, and trading that good for the other.

Example 1

Two men live alone on an isolated island. To survive they must undertake a few basic economic activities like water carrying, fishing, cooking and shelter construction and maintenance. The first man is young, strong, and educated. He is also faster, better, and more productive at everything. He has an absolute advantage in all activities. The second man is old, weak, and uneducated. He has an absolute disadvantage in all economic activities. In some activities the difference between the two is great; in others it is small.
Despite the fact that the younger man has absolute advantage in all activities, it is not in the interest of either of them to work in isolation since they both can benefit from specialization and exchange. If the two men divide the work according to comparative advantage then the young man will specialize in tasks at which he is most productive, while the older man will concentrate on tasks where his productivity is only a little less than that of the young man. Such an arrangement will increase total production for a given amount of labor supplied by both men and it will benefit both of them.

Example 2

Suppose there are two countries of equal size, Northland and Southland, that both produce and consume two goods, food and clothes. The productive capacities and efficiencies of the countries are such that if both countries devoted all their resources to food production, output would be as follows:
Northland: 100 tonnes
Southland: 400 tonnes
If all the resources of the countries were allocated to the production of clothes, output would be:
Northland: 100 tonnes
Southland: 200 tonnes
Assuming each has constant opportunity costs of production between the two products and both economies have full employment at all times. All factors of production are mobile within the countries between clothes and food industries, but are immobile between the countries. The price mechanism must be working to provide perfect competition.
Southland has an absolute advantage over Northland in the production of food and clothes. There seems to be no mutual benefit in trade between the economies, as Southland is more efficient at producing both products. The opportunity costs shows otherwise. Northland's opportunity cost of producing one tonne of food is one tonne of clothes and vice versa. Southland's opportunity cost of one tonne of food is 0.5 tonne of clothes, and its opportunity cost of one tonne of clothes is 2 tonnes of food. Southland has a comparative advantage in food production, because of its lower opportunity cost of production with respect to Northland, while Northland has a comparative advantage in clothes production, because of its lower opportunity cost of production with respect to Southland.
To show these different opportunity costs lead to mutual benefit if the countries specialize production and trade, consider the countries produce and consume only domestically. The volumes are:
Production and consumption before trade
Country Food Clothes
Northland 50 50
Southland 200 100
TOTAL 250 150
This example includes no formulation of the preferences of consumers in the two economies which would allow the determination of the international exchange rate of clothes and food. Given the production capabilities of each country, in order for trade to be worthwhile Northland requires a price of at least one tonne of food in exchange for one tonne of clothes; and Southland requires at least one tonne of clothes for two tonnes of food. The exchange price will be somewhere between the two. The remainder of the example works with an international trading price of one tonne of food for 2/3 tonne of clothes.
If both specialize in the goods in which they have comparative advantage, their outputs will be:
Production after trade
Country Food Clothes
Northland 0 100
Southland 300 50
TOTAL 300 150
World production of food increased. clothes production remained the same. Using the exchange rate of one tonne of food for 2/3 tonne of clothes, Northland and Southland are able to trade to yield the following level of consumption:
Consumption after trade
Country Food Clothes
Northland 75 50
Southland 225 100
World total 300 150
Northland traded 50 tonnes of clothes for 75 tonnes of food. Both benefited, and now consume at points outside their production possibility frontiers.
Assumptions in Example 2:
Two countries, two goods - the theory is no different for larger numbers of countries and goods, but the principles are clearer and the argument easier to follow in this simpler case.
Equal size economies - again, this is a simplification to produce a clearer example.
Full employment - if one or other of the economies has less than full employment of factors of production, then this excess capacity must usually be used up before the comparative advantage reasoning can be applied.
Constant opportunity costs - a more realistic treatment of opportunity costs the reasoning is broadly the same, but specialization of production can only be taken to the point at which the opportunity costs in the two countries become equal. This does not invalidate the principles of comparative advantage, but it does limit the magnitude of the benefit.
Perfect mobility of factors of production within countries - this is necessary to allow production to be switched without cost. In real economies this cost will be incurred: capital will be tied up in plant (sewing machines are not sowing machines) and labour will need to be retrained and relocated. This is why it is sometimes argued that 'nascent industries' should be protected from fully liberalised international trade during the period in which a high cost of entry into the market (capital equipment, training) is being paid for.
Immobility of factors of production between countries - why are there different rates of productivity? The modern version of comparative advantage (developed in the early twentieth century by the Swedish economists Eli Heckscher and Bertil Ohlin) attributes these differences to differences in nations' factor endowments. A nation will have comparative advantage in producing the good that uses intensively the factor it produces abundantly. For example: suppose the US has a relative abundance of capital and India has a relative abundance of labor. Suppose further that cars are capital intensive to produce, while cloth is labor intensive. Then the US will have a comparative advantage in making cars, and India will have a comparative advantage in making cloth. If there is international factor mobility this can change nations' relative factor abundance. The principle of comparative advantage still applies, but who has the advantage in what can change.
Negligible transport cost - Cost is not a cause of concern when countries decided to trade. It is ignored and not factored in.
Before specialization, half of each country's available resources are used to produce each good.
Perfect competition - this is a standard assumption that allows perfectly efficient allocation of productive resources in an idealized free market.

Example 3

The economist Paul Samuelson provided another well known example in his Economics. Suppose that in a particular city the best lawyer happens also to be the best secretary, that is he would be the most productive lawyer and he would also be the best secretary in town. However, if this lawyer focused on the task of being a lawyer and, instead of pursuing both occupations at once, employed a secretary, both the output of the lawyer and the secretary would increase, as it is more difficult to be a lawyer than a secretary.
[edit]Effect of trade costs

Trade costs, particularly transportation, reduce and may eliminate the benefits from trade, including comparative advantage. Paul Krugman gives the following example.[5]
Using Ricardo's classic example:
Unit labor costs
Cloth Wine
Britain 100 110
Portugal 90 80
In the absence of transportation costs, it is efficient for Britain to produce cloth, and Portugal to produce wine, as, assuming that these trade at equal price (1 unit of cloth for 1 unit of wine) Britain can then obtain wine at a cost of 100 labor units by producing cloth and trading, rather than 110 units by producing the wine itself, and Portugal can obtain cloth at a cost of 80 units by trade rather than 90 by production.
However, in the presence of trade costs of 15 units of labor to import a good (alternatively a mix of export labor costs and import labor costs, such as 5 units to export and 10 units to import), it then costs Britain 115 units of labor to obtain wine by trade – 100 units for producing the cloth, 15 units for importing the wine, which is more expensive than producing the wine locally, and likewise for Portugal. Thus, if trade costs exceed the production advantage, it is not advantageous to trade.
Krugman proceeds to argue more speculatively that changes in the cost of trade (particularly transportation) relative to the cost of production may be a factor in changes in global patterns of trade: if trade costs decrease, such as on the advent of steam-powered shipping, trade should be expected to increase, as more comparative advantages in production can be realized. Conversely, if trade costs increase, or if production costs decrease faster than trade costs (such as via electrification of factories), then trade should be expected to decrease, as trade costs become a more significant barrier.

Effects on the economy

Conditions that maximize comparative advantage do not automatically resolve trade deficits. In fact, many real world examples where comparative advantage is attainable may require a trade deficit. For example, the amount of goods produced can be maximized, yet it may involve a net transfer of wealth from one country to the other, often because economic agents have widely different rates of saving.
As the markets change over time, the ratio of goods produced by one country versus another variously changes while maintaining the benefits of comparative advantage. This can cause national currencies to accumulate into bank deposits in foreign countries where a separate currency is used.
Macroeconomic monetary policy is often adapted to address the depletion of a nation's currency from domestic hands by the issuance of more money, leading to a wide range of historical successes and failures.
[edit]Considerations

Development economics

The theory of comparative advantage, and the corollary that nations should specialize, is criticized on pragmatic grounds within the import substitution industrialization theory of development economics, on empirical grounds by the Singer–Prebisch thesis which states that terms of trade between primary producers and manufactured goods deteriorate over time, and on theoretical grounds of infant industry and Keynesian economics. In older economic terms, comparative advantage has been opposed by mercantilism and economic nationalism. These argue instead that while a country may initially be comparatively disadvantaged in a given industry (such as Japanese cars in the 1950s), countries should shelter and invest in industries until they become globally competitive. Further, they argue that comparative advantage, as stated, is a static theory – it does not account for the possibility of advantage changing through investment or economic development, and thus does not provide guidance for long-term economic development.
Much has been written since Ricardo as commerce has evolved and cross-border trade has become more complicated. Today trade policy tends to focus more on "competitive advantage" as opposed to "comparative advantage". One of the most indepth research undertakings on "competitive advantage" was conducted in the 1980s as part of the Reagan administration's Project Socrates to establish the foundation for a technology-based competitive strategy development system that could be used for guiding international trade policy.

Free mobility of capital in a globalized world

Ricardo explicitly bases his argument on an assumed immobility of capital:
" ... if capital freely flowed towards those countries where it could be most profitably employed, there could be no difference in the rate of profit, and no other difference in the real or labour price of commodities, than the additional quantity of labour required to convey them to the various markets where they were to be sold."
He explains why, from his point of view, (anno 1817) this is a reasonable assumption: "Experience, however, shows, that the fancied or real insecurity of capital, when not under the immediate control of its owner, together with the natural disinclination which every man has to quit the country of his birth and connexions, and entrust himself with all his habits fixed, to a strange government and new laws, checks the emigration of capital."
Some scholars, notably Herman Daly, an American ecological economist and professor at the School of Public Policy of the University of Maryland, have voiced concern over the applicability of Ricardo's theory of comparative advantage in light of a perceived increase in the mobility of capital: "International trade (governed by comparative advantage) becomes, with the introduction of free capital mobility, interregional trade (governed by Absolute advantage)."
Adam Smith developed the principle of absolute advantage. The economist Paul Craig Roberts notes that the comparative advantage principles developed by David Ricardo do not hold where the factors of production are internationally mobile.[8][9] Limitations to the theory may exist if there is a single kind of utility. Yet the human need for food and shelter already indicates that multiple utilities are present in human desire. The moment the model expands from one good to multiple goods, the absolute may turn to a comparative advantage. The opportunity cost of a forgone tax base may outweigh perceived gains, especially where the presence of artificial currency pegs and manipulations distort trade. Global labor arbitrage, where one country exploits the cheap labor of another, would be a case of absolute advantage that is not mutually beneficial.
Economist Ha-Joon Chang criticized the comparative advantage principle, contending that it may have helped developed countries maintain relatively advanced technology and industry compared to developing countries. In his book Kicking Away the Ladder, Chang argued that all major developed countries, including the United States and United Kingdom, used interventionist, protectionist economic policies in order to get rich and then tried to forbid other countries from doing the same. For example, according to the comparative advantage principle, developing countries with a comparative advantage in agriculture should continue to specialize in agriculture and import high-technology widgits from developed countries with a comparative advantage in high technology. In the long run, developing countries would lag behind developed countries, and polarization of wealth would set in. Chang asserts that premature free trade has been one of the fundamental obstacles to the alleviation of poverty in the developing world. Recently, Asian countries such as South Korea, Japan and China have utilized protectionist economic policies in their economic development