BEA recommends using estimates of real economic growth that are based on chain-type quantity indexes or chained dollars. The method for computing contributions to growth is discussed in the article "A Preview of the 1999 Comprehensive Revision of the National Income and Product Accounts: Statistical Changes," in the October 1999 Survey of Current Business. This formula eliminates problems with the non-additivity of component industries to total product (GDP or GDP by state) when valued in chained dollars. An individual industry's contribution to the percent change in total chained-dollar product is given by:
For additional discussion of the issues involved in analyzing real economic growth based on chain-type quantity indexes or chained dollars measures, refer to the box, "Using Chained Dollar Estimates for Computing Contributions to Economic Growth: A Cautionary Note," in: Lum, Sherlene K. S. and Brian C. Moyer, "Gross Product by Industry, 1995-97," Survey of Current Business 78 (November 1998): 20-40.