Title: A concordance between ten-digit U.S. harmonized system codes and SIC/NAIC's product classes and industries
Description: "This paper provides and describes concordances between the ten-digit Harmonized System (HS) categories used to classify products in U.S.  international trade and the four-digit SIC and six-digit NAICS industries that cover the years 1989 to 2006.  We also provide concordances between ten-digit HS codes and the five-digit SIC and seven-digit NAICS product classes used to classify U.S.  manufacturing production.  Finally, we briefly describe how these concordances might be applied in current empirical international trade research"--National Bureau of Economic Research web site.