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.

Seasonal Adjustment Publication Changes
Beginning with the release of the 2012 Benchmark, on February 1, 2013, CES began publishing additional seasonally adjusted series with each second preliminary estimate. All the necessary files and data for these series are now available, along with the information provided for the published seasonally adjusted series, with the first preliminary estimates. More information on seasonally adjusted structure publication changes is available at www.bls.gov/web/empsit/cesnewseries.htm and in the most current Benchmark Article at www.bls.gov/web/empsit/cesbmart.htm.

Seasonal adjustment in the CES program
Technical information on CES seasonal adjustment, including a detailed description of input files and methodology. (HTML) (PDF)

Seasonal adjustment model specification list
The annually updated seasonal adjustment model specification list can be found in the most current Benchmark Article. (HTML) (PDF)

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)

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Development of seasonally adjusted data for first preliminary 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.

Note: The files in this section are equivalent to the files available prior to the 2012 Benchmark release, and were used in seasonally adjusting first preliminary estimates. The ZIP file containing the prior adjustments and manual outliers is now in the last section, Other data used in seasonal adjustment.

• UPDATED Seasonal adjustment input specification files: all employees (Zip File) -- Specification files used as input to X-12-ARIMA for the CES all employees seasonally adjusted series that aggregate to Total nonfarm. Included is a readme.txt file that provides a brief description of the specification files and viewing instructions. The files have been compressed.
• UPDATED Seasonal adjustment input specification files: all employee hours and earnings (Zip File) -- Specification files used as input to X-12-ARIMA for the CES all employees hours and earnings seasonally adjusted series that aggregate to Total nonfarm. Included is a readme.txt file that provides a brief description of the specification files and viewing instructions. The files have been compressed.
• UPDATED Seasonal adjustment input specification files: all other data types (Zip File) -- Specification files used as input to X-12-ARIMA for all CES data types other than all employees or all employees hours and earnings seasonally adjusted series that aggregate to Total nonfarm.. Included is a readme.txt file that provides a brief description of the specification files and viewing instructions. The files have been compressed.

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Development of seasonally adjusted data for second preliminary estimates
Note: The files in this section relate to detailed series not published prior to the 2012 Benchmark release. The ZIP file containing the prior adjustments is located in the last section, Other data used in Seasonal Adjustment. The prior adjustment files are appropriate for use with these series; however, manual outliers identified for the first closing series are not applied to any detailed seasonally adjusted series available at second closing.

• NEW Seasonal adjustment input specification files: all employees, independent series (Zip File) -- Specification files used as input to X-12-ARIMA for the CES all employees independent seasonally adjusted series. Included is a readme.txt file that provides a brief description of the specification files and viewing instructions. The files have been compressed.
• NEW Seasonal adjustment input specification files: all employee hours and earnings, independent series (Zip File) -- Specification files used as input to X-12-ARIMA for the CES all employees hours and earnings independent seasonally adjusted series. Included is a readme.txt file that provides a brief description of the specification files and viewing instructions. The files have been compressed.
• NEW Seasonal adjustment input specification files: all other data types, independent series (Zip File) -- Specification files used as input to X-12-ARIMA for all CES data types other than all employees or all employees hours and earnings seasonally adjusted series that aggregate to Total nonfarm.. Included is a readme.txt file that provides a brief description of the specification files and viewing instructions. The files have been compressed.

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Other data used in Seasonal Adjustment

• 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.

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Last Modified Date: February 5, 2013