An official website of the United States government
The Current Population Survey (CPS) is based on a sample of U.S. households. Each month, approximately 60,000 scientifically selected households are contacted for participation in the survey so that the BLS can publish timely information about the U.S. labor market, such as the unemployment rate.
Statistics based on the CPS are subject to sampling and nonsampling error. When a sample, rather than the entire population, is surveyed, estimates may differ from the true population values that they represent. The component of this difference that occurs because samples differ by chance is known as sampling error, and its variability is measured by the standard error of the estimate.
An estimate and its respective standard error can be used to build a confidence interval, which is a range of values centered around the estimate that is likely to include the true population value with a degree of confidence. BLS analyses are generally conducted at the 90-percent level of confidence.
Estimates from the CPS are also affected by nonsampling error, which can occur for many reasons, including the failure to sample a segment of the population, inability to obtain information for all respondents in the sample, inability or unwillingness of respondents to provide correct information, mistakes made by respondents, and errors made in the collection or processing of the data. A discussion of nonsampling error is available in Chapter 4.1 of the Current Population Survey Design and Methodology (Technical paper 77, October 2019).
There are tools available for examining the reliability of CPS estimates and determining whether estimates are statistically different from each other:
Last modified date: November 21, 2025