The question then becomes how to construct a data series that reflects the full range of industries and activities included within "outsourcing." Several different approaches can shed light on this phenomena. A starting point is to examine what has happened to the composition of U.S. trade using the "end-use" categories of the Bureau of Economic Analysis (as suggested by Irwin, 1996). Rather than assign- ing goods by their production process, these categories assign them according to their use by purchasers. T