In Chapter I we established that the export dependence thesis could be most fruitfully (although not necessarily most easily) tested with regard to manufactured exports and the United States. Accordingly, in this chapter the effect of export dependence on U.S. commercial policy is examined in an aggregate data analysis of 129 manufacturing sectors. The 129 sectors are based on the three-digit industry groups of the Standard Industrial Classification (SIC) and comprehensively cover the full range of U.S. manufacturing activity as classified by the SIC. 1