Now, exactly the same case is presented in almost every simple neighborhood trade. The proprietor may be able to keep his books better than does the bookkeeper whom he employs. The merchant may be able to sweep out the store better than the cheap boy does it. The carpenter may be able to raise better vegetables than can the gardener from whom he purchases. Yet the merchant does not turn to sweeping and the carpenter to raising vegetables, because if they did they would have to quit or limit by so much their present better-paying work, and would lose far more than they would gain.
So whenever the people in one country have a greater advantage in one article than in another, relative to another country, the foreigners, like the low-paid man, will be willing to exchange at a ratio that will make it profitable to specialize in the product wherein the greater superiority lies.[7]
But this is always hard doctrine for the popular mind, and particularly for the commercial mind endeavoring to carry on a business that can not be made "to pay" in the face of foreign competition. It is easy to believe that a country ought not to import goods unless it is at an absolute disadvantage in their production. It is often declared that as our country can produce any kind of goods "as well" as foreign countries (meaning with as few days' labor), there is a loss on every unit imported. The fundamental principle of trade as applied to such cases shows that not the advantage which one country enjoys over the other as to a single product determines whether it will gain by producing at home, but the comparative advantages enjoyed in the production of the two articles in question.
As a simple example, suppose that a day's labor in country A will secure two bushels of wheat (2x) and two hundred pounds of iron (2y), whereas in B a day's labor will secure 1x or 2y. Then A's comparative advantage in producing x becomes a reason for A's not trying to produce y. Trade can take place (aside from transportation outlay) at any ratio between 2x = 2x (A's minimum) and 2x = 4y (B's maximum). Evidently at any rate between these two ratios each party would gain something by the trade, e.g., at 2x = 3y A would get 3 instead of 2y by a day's labor, and B would get 1-1/3x instead of 1x for a day's labor (2x for 1-1/2 day's labor instead of for two days'). If, however, A could produce exactly twice as much of everything as B could, then there could be no motive on either side for trade. But this never happens.
§ 6. #Equation of international exchange.# Foreign trade of course can take place as barter, and in earlier times, particularly, very commonly did so. But in the existing monetary economy nearly all trades are expressed in terms of monetary prices. Both the prices of all the particular objects of international trade and the general levels of prices in any two trading countries come to be pretty definitely interrelated. Changes in the one country at once compel readjustments in the other. To understand in the most general way how this occurs, a knowledge at least of the elementary principles of foreign exchange is required, and to this we may now turn.
Let us begin with the proposition known as the equation of international exchange, which is sometimes given thus: the value of the imports of a country must in the long run equal the value of the exports. But this proposition (especially the words imports and exports) must be understood in a much broader sense than that of the movements of merchandise merely. The proposition might better be expressed: the total credits of a nation (including money actually sent abroad) must just equal its total debits (including money imported). Into the balance of accounts between any two nations enter many items: the cash values of the imports and exports of merchandise; freights, insurance premiums, and commissions; the expenses of citizens while traveling abroad; money brought in or taken out by immigrants; the cost of the governmental foreign services (such as the salaries of consuls and of diplomatic representatives); subsidies and war indemnities received from or paid to foreign nations; the investments of foreign capital; and credit items of many kinds, on both sides of the account.
The effect of loans upon the equation differs at different periods according as they are just being made, are continuing, or are being repaid. When foreign capital is first invested in a country, whether it is loaned to the government or to individuals or to corporations, either gold must be remitted to the borrowing country or goods be sent. But later the interest payments and the eventual repayment of the principal of the loan act in the opposite direction. Accruing interest must be offset annually by exports from the debtor country and the repayment of the principal requires that either money or goods be exported equal in value to the original obligations. In popular opinion an excess of exports of merchandise is an index, if not the real cause, of national prosperity; but evidently it is no true index whatever on this point. An excess of exports may at any given moment indicate that the country is rich and is lending abroad, or that it is in debt and is paying interest, or that it is repaying the principal. On the other hand, an excess of imports may indicate either that a country is poor, and is borrowing from abroad, or that it is rich, with many foreign investments, and is receiving the income from them in the form of a regular shipment of goods from the debtors.
The following statistics of the foreign commerce (merchandise imports and exports) of the principal countries of the world are given in significant groupings which call for various explanations.
Figures are in million dollars ($1,000,000) and are mostly for the year 1908, (Stat. Abst. 1908, p. 769). At the present writing the war has altered all the lines of commerce.