How do the NAICS industry indexes compare to SIC indexes?
Two criteria were applied to determine if the new and old series are comparable. The first criterion is based on the overlap of employment between the two series. For example, a NAICS series is deemed comparable to the corresponding SIC series only if at least 90 percent of the employment in the NAICS classification is also in the SIC classification, and at least 90 percent of the employment in the SIC classification is also in the NAICS classification. If the first test was passed, a second test compared the old and new index series. A series was considered continuous in the NAICS index when it was within 1.5 index points of the SIC series for the period December 1994 through December 2004. For the ECI, all of the industry and occupational series that met the first employment overlap criteria also passed the second index comparison test. Table 1 shows the NAICS industry indexes that will be published starting March 2006, and indicates series which have met the comparability tests, as
