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Quarterly Census of Employment and Wages

BLS Completes Release of Expanded Historical NAICS Basis Data

BLS has released reconstructed NAICS basis data for the years 1990 and 1991 from the Quarterly Census of Employment and Wages program (QCEW).  This complements the earlier release of data for 1992 through 2000. QCEW is the name of the Covered Employment and Wages program, formerly known as the ES-202 program. This release includes annual averages of establishments, employment, weekly wages, and average annual wages and total annual wages. Also included are monthly employment, quarterly establishment counts, quarterly wage totals, and quarterly average weekly wages. Data on Unemployment Insurance (UI) taxable wages, and UI contributions are not available. Data for the years 1990 through 2000 were released as they were developed, with the most recent years released first. Data for the entire 1990-2000 period are available as of the end of September 2004.

Period Covered by This Release

This release covers 1990 and 1991.

Flat Files (FTP)

The FTP directories were updated on September 27, 2004. They include all the reconstructed NAICS basis QCEW data published by BLS. This includes detailed industry data available at county, MSA, State, and national levels. Establishment data are available in quarterly and annual form. Employment is available on a monthly and annual basis. Total wages are available on a quarterly and annual basis. The quarterly wages are available as a total and as average weekly wages. The annual wages are available as an annual total and as annual average wages and average weekly wages.

Data Access & Tools

The BLS database that supports the Most Requested Statistics tool, the Create Customized Tables tools (both the one screen version and the multiple screen version) and the Series Report tool is planned to be updated in 2005. As is the case with current quarterly data from the QCEW program, the data to be included on the database will be a subset of the complete file. The exact composition of the subset has not been determined.


The fundamental methodology of the data reconstruction is the same as that of the base QCEW program. Individual establishment reports have been classified by industry, ownership, area, and establishment size. These are then aggregated to the various publication levels. The most detailed are data at the 6-digit NAICS industry level, by ownership, by county. The most comprehensive is total U.S. Covered Employment. The methodological difference is that NAICS industry codes were not generally assigned to the establishment reports at the time the data were collected. Instead, a variety of techniques have been utilized to assign industry classifications for those establishments.

The reconstructed data is based on datasets of establishment reports that differ from those used to create corresponding SIC based QCEW data for the same period. The resulting economic data are generally similar to the previously released SIC-based QCEW data. There are also differences between the reconstructed NAICS basis data and the NAICS employment estimates for this period produced by the Current Employment Statistics (CES) program.

There were approximately 5 million data series released as a result of the QCEW NAICS reconstruction effort. Because of the volume of the data, and the methodology used to construct it, the QCEW reconstructed NAICS data may exhibit characteristics such as jumps between periods. BLS believes the reconstructed NAICS data will be a useful tool for many types of economic analysis.

In contrast, with about 25,000 series, the CES program reviewed the historic NAICS data they have released. As part of this review, efforts were made to make the data suitable for a broad variety of time series analysis purposes. Where CES data are available, the CES data should be considered preferable for use.

Disclosure Methodology

Industry classification on a NAICS basis, while broadly different from industry classification on an SIC basis, is also quite similar. The existence of two datafiles (one SIC based and one NAICS based) has the potential to permit cross-tabulations that would allow the isolation of individual establishment reports. The methodology BLS has chosen to produce the reconstructed NAICS data was integrated with a disclosure processing methodology which will reasonably protect against such possibilities. One aspect of that methodology is particularly noteworthy for data users. In contrast to the practice used for current period data, (essentially all QCEW data but the reconstructed NAICS data) files and databases that contain reconstructed data, will not contain entries for industries and aggregations that failed BLS's confidentiality tests. In the current period data, the files and databases would contain an entry that indicated that the data were not disclosable. Under both disclosure practices, upper level industry aggregates include the nondisclosable data that contributed to the upper levels. As a result, users may not see all of the data that add up to the upper levels.

Area Classification

The QCEW data on a reconstructed NAICS basis are also available aggregated to Core Based Statistical Area (CBSA) definitions, such as Metropolitan Statistical Areas (MSAs), Micropolitan Statistical Areas (MicroSAs), and Combined Statistical Areas (CSAs). The reconstructed CBSA level data are based on the Office of Management and Budget's CBSA definitions as of March 17, 2004.


Last Modified Date: October 6, 2004