Employment Cost Index Technical Note

					   TECHNICAL NOTE
					   
The Employment Cost Index (ECI) measures the change in the cost of labor, free from the influence of 
employment shifts among occupations and industries. For information on survey concepts, coverage, 
methods, nonresponse adjustment, and imputation, see Employment Cost Index Handbook of Methods at 
www.bls.gov/opub/hom/eci/home.htm.

Sample size: Data for this reference period were collected from a probability sample of approximately
28,500 occupational observations selected from a sample of about 6,700 private industry establishments
and approximately 7,300 occupational observations selected from a sample of about 1,400 state and local
government establishments that provided data at the initial interview.

Standard errors: To assist users in ascertaining the reliability of ECI series, standard errors of all
current quarter not seasonally adjusted 3- and 12-month percent change series are also available, see 
www.bls.gov/eci/factsheets/eci-standard-errors.htm and the database query tool at 
www.bls.gov/eci/data.htm. Standard errors provide users a measure of the precision of an estimate to 
ensure that it is within an acceptable range for their intended purpose. 

Historical listings: Historical tables are available in XLSX format for constant dollar, current dollar,
and continuous series, see www.bls.gov/eci/tables.htm. The continuous occupational and industry series 
listing uses the Standard Industrial Classification (SIC) Manual and Occupational Classification System
(OCS) series from 1975 through 2005 and the North American Industry Classification System (NAICS) and 
Standard Occupational Classification (SOC) from 2006 to the present. It provides the official series 
deemed continuous after the change in classification systems. For more information on the criteria used
in defining continuous series, see the article published in the Monthly Labor Review at 
www.bls.gov/opub/mlr/2006/04/art2full.pdf. 

Employer Costs for Employee Compensation data: The costs per hour worked of compensation components are 
published as part of the Employer Costs for Employee Compensation (ECEC) news release. The ECEC release 
dates are available at www.bls.gov/schedule/news_release/ecec.htm. Historical ECEC data are available in
XLSX format at www.bls.gov/ecec/tables.htm. Since the ECEC is calculated with current employment weights
rather than the fixed weights used in computing the ECI, year-to-year changes in the cost levels usually
differ from those in the ECI.

Fixed employment weights: Fixed employment weights are updated periodically to reflect the current 
industry and occupational employment distributions, see 
www.bls.gov/eci/factsheets/eci-reweighting-and-recoding.htm. 

Seasonal factors: Detailed information on seasonal factors for the 2026 reference year and the revisions
of historical seasonally adjusted data for the most recent five years can be found at 
www.bls.gov/eci/factsheets/annual-seasonal-adjustment.htm. More information on seasonal adjustment can
be found at www.bls.gov/opub/mlr/2024/article/seasonality-in-the-employment-cost-index.htm. 

Additional information: ECI release dates are available on the release calendar at 
www.bls.gov/schedule/news_release/eci.htm. Subscribe to receive the BLS Economic News Release email at
public.govdelivery.com/accounts/USDOLBLS/subscriber/new. 

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