In the 2003 comprehensive revision, the estimates of income and employment-by-industry were converted to the 1997 North American Industry Classification System. The increased detail provided by NAICS improves the placement of primary activities among NIPA subcomponents, and because of the differences between NAICS and the Standard Industrial Classification (SIC), the methodologies used to estimate some NIPA components changed.

The income and employment-by-industry tables that were affected by this conversion are Tables 6.1-6.22. 

The SIC and the NAICS overlap years for these tables is 1998-2000. Annual estimates are presented on a NAICS basis beginning with 1998.

Personal consumption expenditures and private fixed investment in equipment and software are classified by type of product rather than by industry, thus the conversion to the NAICS standard did not directly impact these estimates. However, since some components within personal consumption expenditures and private fixed investment are estimated based upon industry source data that was converted to the NAICS standard, there were indirect effects on these estimates. For more information on the impacts of conversion to the NAICS standard, see Preview of Revised NIPA Estimates for 1997: Effects of Incorporating the 1997 Benchmark I-O Accounts and Proposed Definitional and Statistical Changes, Stephanie H. McCulla and Carol E. Moylan, Survey of Current Business, January 2003 [PDF, Tables in XLS format]