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 National Compensation Measures 
Handbook of Methods at www.bls.gov/opub/hom/ncs/home.htm.

Sample size
Data for this reference period were collected from a probability sample of approximately 28,100 
occupational observations selected from a sample of about 7,000 private industry establishments and 
approximately 7,600 occupational observations selected from a sample of about 1,400 state and local 
government establishments that provided data at the initial interview. Beginning December 2021, an 
additional (fourth) private industry sample is used in estimation to mitigate the impact of 
decreasing response rates.

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 ECI data are available in xlsx format at 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/eci/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
For additional information on the use of fixed employment weights in computing the ECI, see 
www.bls.gov/opub/mlr/2016/article/introducing-2012-fixed-employment-weights-for-the-
employment-cost-index.htm. Beginning with the December 2022 release, the ECI is introducing new
employment weights, see www.bls.gov/eci/notices/2022/eci-2021-fixed-weights-and-2018-socupdate.htm.

Additional information
Historical tables are available in xlsx format for constant dollar, current dollar, and continuous
series, see www.bls.gov/eci/tables.htm. 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. If you are 
deaf, hard of hearing, or have a speech disability, please dial 7-1-1 to access telecommunications 
relay services.