ABSTRACT
The classical theory of international trade was formulated primarily with a view to its providing guidance on questions of national policy, and although it included considerable descriptive analysis of economic process, the selection of phenomena to be scrutinized and problems to be examined was almost always made with reference to current issues of public interest. This was true even of the classical discussions of the mechanism of international trade, but it was more conspicuously true in the field which is sometimes called "the theory of international value," where the problems were expressly treated with reference to their bearing on "gain" or "loss" to England, or on the distribution of gain as between England and the rest of the world. Recognition of its "welfare analysis" orientation is essential to the understanding and the appraisal of the classical doctrine. Although the classical economists did not clearly separate them, and shifted freely from one to the other, they followed three different methods of dealing with the question of "gain" from trade: (I) the doctrine of comparative costs, under which economy in cost of obtaining a given income was the criterion of gain; (2) increase in income as a criterion of gain; and (3) terms of trade as an index of the international division and the trend of gain. This chapter will deal with the doctrine of comparative costs.
