Labor Force Statistics from the Current Population Survey

Technical Documentation

This page contains technical documentation and related information on the Current Population Survey (CPS).

On This Page


Concepts and methodology of the CPS

Summarized documentation on the concepts and methodology of the CPS.

Comprehensive documentation on the design and methodology of the CPS, including a history of the survey (links to the Census Bureau website).

Historical comparability is affected by revisions to population controls, changes in occupational and industry classification, and other changes to the survey.


CPS and CES employment differences

There are two monthly surveys that provide sample-based estimates of employment: the CPS, also known as the household survey, and the Current Employment Statistics (CES) survey, also known as the establishment or payroll survey. The establishment survey employment series has a smaller margin of error on the measurement of month-to-month change than the household survey because of its much larger sample size. However, the household survey has a more expansive scope than the establishment survey because it includes the self-employed, unpaid family workers, agricultural workers, and private household workers, who are excluded by the establishment survey. The household survey also provides estimates of employment for demographic groups.


How the government measures unemployment

Description of how the national unemployment statistics are developed from the Current Population Survey (CPS), written in non-technical language.


Occupational and industry classifications used in the CPS

BLS publishes both employment and unemployment data by occupation and industry from the CPS.

The occupational classification reflects the type of job or work that the person does, while the industry classification reflects the business activity of their employer or company. The occupational and industry classifications are based on a person’s sole or primary job, unless otherwise specified. For the unemployed, the occupation and industry are based on the last job held.

The Current Population Survey currently uses the 2010 Census occupational classification and, beginning with data for January 2014, the 2012 Census industry classification. These classifications were derived from the 2010 Standard Occupational Classification (SOC) and the 2012 North American Industry Classification System (NAICS), respectively, to meet the special classification needs of demographic household surveys. The Census classifications use the same basic structure as the SOC and NAICS, but are generally less detailed.

More information about the Census occupational and industry classifications is available from the Census Bureau, including indexes showing where specific jobs and industries are classified.

Learn more about the historical comparability of occupation and industry data from the CPS.


Population control adjustments to the CPS

Population controls are independent estimates of population used to weight the CPS sample results. The CPS population controls are developed by the U.S. Census Bureau. They are based on decennial census information as well as administrative data such as birth and death statistics and estimates of net international migration. Information about the Census Bureau's population estimation methodology is available on their website at http://www.census.gov/popest/methodology/.

The Census Bureau reviews and adjusts the CPS population controls every year. BLS introduces the annual population control adjustments into the CPS estimates beginning with the January data. The adjustments may increase or decrease the population level, depending on whether the latest information indicates the population estimates have trended high or low. Conceptually, the population control adjustments represent the cumulative over- or under-estimation of the population since the last decennial census point.

The results from Census 2010 were incorporated into CPS population controls with the release of data for January 2012. CPS estimates for January 2000 through December 2011 reflect population controls based on Census 2000.

Level shifts in the CPS labor force and employment series may sometimes result from the annual population control adjustments. Significant level shifts may make it difficult for data users to evaluate changes over time periods that include these adjustments. As a convenience to data users, BLS created research series that smooth out level shifts in the labor force and employment estimates resulting from the January 2000 and subsequent population control adjustments.

NOTICE Because the January 2014 population control adjustments had a negligible effect on survey estimates, the smoothed labor force and employment series were not updated. No data were revised, nor were the series extended through December 2013.


Questionnaire for the CPS

Information about the survey collection process, including the questionnaire, is available from the Census Bureau, which conducts the CPS.


Reliability of estimates from the CPS

Statistics from the CPS are subject to both sampling and nonsampling error. When a sample rather than the entire population is surveyed, there is a chance that the sample estimates may differ from the "true" population values they represent. The exact difference, or sampling error, varies depending on the particular sample selected, and this variability is measured by the standard error of the estimate.


Research articles

Browse recent BLS analyses of CPS data by topic: unemployment, labor force characteristics, earnings, and demographic characteristics.


Seasonal adjustment of CPS estimates

Over the course of a year, the size of the labor force, the levels of employment and unemployment, and other measures of labor market activity undergo sharp fluctuations due to such seasonal events as changes in weather, major holidays, and the opening and closing of schools. Because these seasonal events follow a more or less regular pattern each year, their influence on statistical trends can be eliminated by adjusting the statistics from month to month. These adjustments make it easier to observe the cyclical and other nonseasonal movements in the series. BLS regularly produces seasonally adjusted series for selected labor force data from the CPS.

Last Modified Date: April 29, 2014

Recommend this page using: