§ 8. We have now arrived at what seems a law of International Values, of great simplicity and generality. But we have done so by setting out from a purely arbitrary hypothesis respecting the relation between demand and cheapness. We have assumed their relation to be fixed, though it is essentially variable. We have supposed that every increase of cheapness produces an exactly proportional extension of demand; in other words, that the same invariable value is laid out in a commodity whether it be cheap or dear; and the law which we have investigated holds good only on this hypothesis, or some other practically equivalent to it. Let us now, therefore, combine the two variable elements of the question, the variations of each of which we have considered separately. Let us suppose the relation between demand and cheapness to vary, and to become such as would prevent the rule of interchange laid down in the last theorem from satisfying the conditions of the Equation of International Demand. Let it be supposed, for instance, that the demand of England for linen is exactly proportional to the cheapness,
the German cost of production (viz. for two millions of linen) and would gain the whole advantage of the trade, Germany being no better off than before.
That such, however, would not be the practical result, will soon be evident. The residuary demand of Germany for 200,000 yards of cloth furnishes a resource to England for purposes of foreign trade of which it is still her interest to avail herself; and though she has no more labour and capital which she can withdraw from linen for the production of this extra quantity of cloth, there must be some other commodities in which Germany has a relative advantage over her (though perhaps not so great as in linen): these she will now import, instead of producing, and the labour and capital formerly employed in producing them will be transferred to cloth, until the required amount is made up. If this transfer just makes up the 200,000 and no more, this augmented n will now be equal to m; England will sell the whole 1,200,000 at the German values; and will still gain the whole advantage of the trade. But if the transfer makes up more than the 200,000, England will have more cloth than 1,200,000 yards to offer; n will become greater than m, and England must part with enough of the advantage to induce Germany to take the surplus. Thus the case which seemed at first sight to be beyond the limits, is transformed practically into a case either coinciding with one of the limits or between them. And so with every other case which can be supposed.
