Offshoring Pollution: Is the United States Increasingly Importing Polluting Goods?

The question posed by the title of this article has been at the heart of debates about pollution havens, industrial flight to developing countries, and now carbon "leakage." Is the United States increasingly importing goods whose production generates relatively more pollution, rather than manufacturing those goods domestically? The consensus seems to be "yes," at least judging by the many public policies designed to counteract this offshoring of pollution. The evidence, however, is mixed, at least in part because empirical research has focused on a slightly different set of questions. After reviewing this research, I present a simple methodology for answering the specific question asked in the title. Using the World Bank's 1987 inventory of industry-specific U.S. air pollution emissions intensities, Bureau of Economic Analysis input-output tables, and data on U.S. imports, I show that from 1972 to 2001 the composition of U.S. imports shifted toward relatively clean goods, rather than polluting goods. Perhaps more surprising, this "green" shift of U.S. imports is even larger than the corresponding green shift of U.S. domestic manufacturing. Based on this analysis, the article concludes that over the past thirty years, the United States does not appear to have been offshoring pollution by importing polluting goods.