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 27,900 
occupational observations selected from a sample of about 6,900 private industry establishments and 
approximately 7,500 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/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
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 introduced new employment weights, see 
www.bls.gov/eci/notices/2022/eci-2021-fixed-weights-and-2018-soc-update.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
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