Every month, usually on the first Friday, the BLS releases its Employment Situation Summary, commonly known as the "US jobs report," among other monthly, quarterly, annual, etc., reports. The methods the BLS uses for the surveys that originate the data for the jobs reports, and how the calculations for the reports are done, are
publicly available government data, published on the BLS website. The BLS collects job data in two separate surveys: the Current Population Survey (CPS) and Current Employment Statistics (CES).
Current Population Survey (CPS) This survey provides data on the employed, unemployed, and those not in the labor force. It measures the
unemployment rate,
labor force participation rate, and
employment-to-population ratio. It is a monthly survey of U.S. households, conducted by the
United States Census Bureau for the BLS. Participation in the survey is voluntary. After the interviews are conducted, the Census Bureau processes the raw data files (as submitted by interviewers) to create a microdata file that can be used to produce estimates. This processing includes removing all personally identifiable information, assigning standardized occupation and industry classifications, editing the data for completeness and consistency, and creating new data elements based on responses to multiple survey questions. Data from field interviewers and centralized call centers are transmitted to Census Bureau headquarters daily during the survey interview period through secure electronic communications. When the Census Bureau's processing activities are completed, the microdata file is securely transferred to the BLS for estimation of labor force statistics.
Current Employment Statistics (CES) This program produces detailed industry estimates of nonfarm employment, hours, and earnings of workers on payrolls. CES National Estimates (CES-N) produces data for the nation, and CES State and Metro Area (CES-SA) produces estimates for all 50 States, the District of Columbia, Puerto Rico, the Virgin Islands, and about 450 metropolitan areas and divisions. Each month, CES surveys approximately 121,000 businesses and government agencies, representing approximately 631,000 individual worksites, drawn from a sampling frame of unemployment insurance tax accounts. Both programs use the same sample and collection methods. Participation in the survey is voluntary under federal law, but it is mandatory in California, New Mexico, Ohio, Oregon, South Carolina, and Puerto Rico. The South Carolina requirement applies to firms with more than 20 employees. The businesses report data on employment, hours, and earnings for all paid workers from their payroll records. The data is collected for the pay period that includes the 12th of the month (regardless of its length), via a form sent to workplaces, by telephone, and online (but not by email, for security reasons). For its monthly estimation, the CES-N program uses a matched sample concept and weighted sample data to produce employment, hours, and earnings estimates. Regarding its reliability, the CES survey, like other sample surveys, is subject to two types of error: sampling and nonsampling error. The magnitude of sampling error, or variance, is directly related to the size of the sample and the percentage of universe coverage achieved by the sample. The CES sample covers over one-third of total universe employment, yielding a very small variance for the total nonfarm estimates. Nonsampling error includes response errors, nonresponse bias, and frame imperfections, such as the inability to account for business births.
Revisions The BLS cautions on its releases page that "data in archived news releases may have been revised in subsequent releases. The latest data, including any revisions, may be obtained from the databases accessible on the program homepages." The primary reasons for the monthly revisions are the collection of additional samples and seasonal adjustments. Also, each year, CES March employment data are reanchored or benchmarked to employment population totals primarily derived from the
Quarterly Census of Employment and Wages. This is done by replacing the March data-based employment estimates with universe counts of employment. The data are also re-seasonally adjusted to account for the benchmark revision and the re-evaluation of outliers and models. "Although revisions can seem disruptive to some users, they are an integral part of the quality control of CES sample-based estimates." The BLS does not wait until it has all the reports to make the estimate and avoid revisions because users of the data are "intensely interested in the earliest possible read on labor market developments." As the revised estimates are based on more complete data, they create a higher resolution picture; sometimes, the revised data produce a totally different picture. Following Trump's firing of Commissioner McEntarfer, the media explained how The Employment Situation reports are made, stating that revisions are not unusual, nor are large changes in them abnormal. The BLS considers its initial job numbers as preliminary when they are first published, because some businesses do not report their payroll data by the deadline (only about 60% do), making the report harder to estimate. The BLS continues collecting the payroll data (three months after the deadline, when more than 90% of workplaces have responded), and revising it according to seasonal adjustments; if more complete data is much above or below the preliminary data, "revisions can be exacerbated by the BLS' seasonal adjustments, which sometimes need to be recalculated." According to the WSJ, the BLS has faced issues with data collection in recent years. Budget cuts—including a governmental hiring freeze earlier this year—and response rates have made providing real-time, accurate data more difficult. For example, the BLS surveys about 120,000 employers by phone or online to track the number of jobs in the economy and about 30% to 40% do not reply on time—up from under 20% a decade ago. According to Barry Knapp of Ironsides Macroeconomics, the model used by BLS systematically overestimates the employment effects of small businesses. At the same time, reduced numbers of job-seeking foreigners are not caused by higher employment but by increased deportations and sinking immigration, which is not reflected in the BLS reports.{{cite web| title = U.S. Payroll Gains Not As Robust As Reported, BLS Data Suggest ==Commissioners==