Employment and wage data developed in the QCEW program have been classified by industry since 1938. An industrial code, based on a description provided by the employer on a questionnaire, is assigned to each establishment by the State workforce agency. If a private or government employer conducts different activities at various establishments or installations, separate industrial codes are assigned, to the extent possible, to each establishment.
The QCEW program has an extensive database of historical and current economic data. While QCEW data are not intended to be a time series, differences in classification systems may lead to perceived discontinuity in QCEW data.
Please refer to the following links for detailed description on each version of NAICS, as well as its predecessor, the Standard Industry Classificatoin (SIC) system.
For a HTML view of the supersector and sector structure of NAICS, please refer to the QCEW supersector page.
There are congruency issues in the NAICS system, where there may be only one 6-digit industry, which is more detailed, under a 5-digit industry. The QCEW program has created an easy-to-read list of all NAICS congruencies. Please refer to the QCEW NAICS congruencies page.
For a break-down of the SIC industries, please refer to the Occupational Safety and Health Administration SIC manual. For more information on QCEW data classified under SIC, please refer to the technical readme.
Last Modified Date: October 21, 2011