U.S. Bureau of Labor Statistics

Current Employment Statistics - CES (National)

Seasonal Adjustment Files and Documentation

Most series published by the Current Employment Statistics program reflect a regularly recurring seasonal movement that can be measured from past experience. By eliminating that part of the change attributable to the normal seasonal variation, it is possible to observe the cyclical and other nonseasonal movements in these series. Seasonally adjusted series are published monthly for selected employment, hours, and earnings estimates.

Below you will find links to technical details and related research on the CES implementation of seasonal adjustment, including input files used during the latest production run. The seasonal adjustment input files have been compressed into zip files. A zip file utility is necessary to extract the files. For more information please visit How to View ZIP Files.

• Seasonal Adjustment in the Current Employment Statistics Program — Technical information on the CES implementation of seasonal adjustment, including a detailed description of input files and methodology used. (HTML) (PDF)
• Seasonal adjustment input specification files: All Employees (Zip File)
— Control (specification) files used as input to X-12-ARIMA for the CES All Employees series. Included is a readme.txt file that provides a brief description of the control files and viewing instructions. The files have been compressed.
• Seasonal adjustment input specification files: All Other Data Types (Zip File)
— Control (specification) files used as input to X-12-ARIMA for all CES data types other than All Employees. Included is a readme.txt file that provides a brief description of the control files and viewing instructions. The files have been compressed.
• UPDATED Other seasonal adjustment input files (Zip File)
— Other files used by CES as input to X-12-ARIMA for seasonal adjustment, including user-defined regression files, a file of prior adjustments, and a file containing recent outliers. Included is a readme.txt file that provides a brief description of the files and instructions. The files have been compressed.
• Seasonal Adjustment Research — Technical research related to seasonal adjustment in the CES program.
  • "Concurrent Seasonal Adjustment for Industry Employment Statistics" (2002) — This examines results from research comparing concurrent seasonal adjustment to projected-factor seasonal adjustment, and discusses the implications of a conversion to concurrent seasonal adjustment by the CES Program. (HTML) (PDF)
  • "Adjusting for Calendar Related Fluctuations in Average Weekly Hours and Average Hourly Earnings Series" (1998) — This research discusses distortions in the CES hours and earnings series caused by differences between reference periods in any given pair of months. In highly seasonal months and industries, this variation can be an important determinant of the magnitude of seasonal hires or layoffs that have occurred at the time the survey was taken, thereby complicating seasonal adjustment. (HTML)
  • "Adjusting for a Calendar Effect in Employment Time Series" (1996) — This research discusses inconsistencies in the seasonally adjusted series that arise because of variations of 4 to 5 weeks between the reference periods in any given pair of months. In highly seasonal months and industries, this variation can be an important determinant of the magnitude of seasonal hires or layoffs that have occurred at the time the survey was taken, thereby complicating seasonal adjustment. (PDF)

Last Modified Date: March 9, 2007