Employment Cost Index Technical Note
Last Modified Date: January 31, 2020
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
Data for this reference period were collected from a probability sample of approximately 25,500
occupational observations selected from a sample of about 6,300 private industry establishments and
approximately 7,800 occupational observations selected from a sample of about 1,400 state and local
government establishments that provided data at the initial interview.
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/ncs/ect/ectvar.htm and the public data query tools at www.bls.gov/ncs/ect/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 are available at www.bls.gov/ect/#tables. The continuous occupational and industry
series listing uses the Standard Industrial Classification Manual and Occupational Classification System
series from 1975 through 2005 and the North American Industry Classification System and Standard
Occupational Classification 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 news release (ECEC). The ECEC release dates are available at
www.bls.gov/schedule/news_release/ecec.htm. Historical ECEC data are available in summary documents at
www.bls.gov/ect/#tables. 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