The open-economy demand curve DD is an odd shape, with two downward- sloping segments separated by a flat segment in the middle: even to the right of B, there are two distinct segments in the developing-country range. The flat segment covers the range of skill supplies in which a trading economy would be diversified, in the sense of continuing to produce both clothing and machinery (albeit in different proportions than under autarky), as for example in a devel- oping country with skill supply Sj. But a country with a high proportion of unskilled workers, as at S2, would not produce machinery; rather it would spe- cialize in clothing (a country with very few unskilled workers, as at S3, would specialize in machinery). Such specialization puts a country on a segment of the demand curve that slopes downward because increases in the relative supply of unskilled labor have to be absorbed by relative-wage-induced changes in the technique chosen to produce the single good.