"it is not a difference in the absolute cost of production, which determines the interchange, but a difference in the comparative cost. It may be to our advantage to procure iron from Sweden in exchange for cottons, even although the mines of England as well as her manufactories should be more productive than those of Sweden; for if we have an advantage of one-half in cottons, and only an advantage of a quarter in iron, and could sell our cottons to Sweden at the price which Sweden must pay for them if she produced them herself, we should obtain our iron with an advantage of one-half as well as our cottons. We may often, by trading with foreigners, obtain their commodities at a smaller expense of labour and capital than they cost to the foreigners themselves. The bargain is still advantageous to the foreigner, because the commodity which he receives in exchange, though it has cost us less, would have cost him more."
To illustrate the cases in which interchange of commodities will not, and those in which it will, take place between two countries, Mr. Mill, in his Elements of Political Economy,[1] makes the supposition that Poland has an advantage over England in the production both of cloth and of corn. He first supposes the advantage to be of equal amount in both commodities; the cloth and the corn, each of which required 100 days' labour in Poland, requiring each 150 days' labour in England. "It would follow, that the cloth of 150 days' labour in England, if sent to Poland, would be equal to the cloth of 100 days' labour in Poland; if exchanged for corn, therefore, it would exchange for the corn of only 100 days' labour. But the corn of 100 days' labour in Poland, was supposed to be the same quantity with that of 150 days' labour in England. With 150 days' labour in cloth, therefore, England would only get as much corn in Poland, as she could raise with 150 days' labour at home; and she would, in importing it, have the cost of carriage besides. In these
- ↑ Third ed. p. 120.