Why did the ECI change to the NAICS and SOC classification systems?
The United States adopted NAICS and SOC as the standard industrial and occupational classification systems to be used by all Federal statistical agencies to provide a means of comparing data across agencies. NAICS was developed collaboratively with Mexico and Canada and is designed to provide comparability between the statistical systems of the three partners in the North American Free Trade Agreement (NAFTA). Information on NAICS and SOC, including background and definitions are available from the BLS websites: www.bls.gov/bls/naics.htm and www.bls.gov/soc/. • How has the ECI changed due to the adoption of NAICS and SOC? As a result of the switch in industry and occupational classifications, some new series have been introduced, some series have been discontinued, and some series from the old structure are either continuous or not continuous with new series. This is not the result of a change in what an establishment or the employees have been doing, but instead stems from a reclassif
