Employment Cost Index Technical Note
Last Modified Date: April 28, 2017
The Employment Cost Index (ECI) measures the change in the cost of labor, free from the influence of
employment shifts among occupations and industries. Detailed information on survey concepts, coverage,
methods, nonresponse adjustment, and imputation can be found in the BLS Handbook of Methods,
Chapter 8, “National Compensation Measures,” at www.bls.gov/opub/hom/pdf/homch8.pdf.
Data for the March 2017 reference period were collected from a probability sample of approximately
27,900 occupational observations selected from a sample of about 6,700 private industry establishments
and approximately 8,100 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 Employment Cost Index (ECI) series, standard errors
of all current quarter estimates except seasonally adjusted series are made available shortly after
publication of the news release. 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. For further information
Health insurance data
Data from the ECI that provide 12-month percent changes in employer costs for health insurance in private
industry are available at www.bls.gov/web/eci/echealth.pdf.
Historical listings that provide all ECI data are available at www.bls.gov/ect/#tables. Included among
these listings is one that provides continuous occupational and industry series. This listing uses the
Standard Industrial Classification Manual and Census of Population series through 2005 and the North
American Industry Classification System and Standard Occupational Classification from 2006 to the
present. It provides the official series from the beginning of the ECI in 1975 through the current
quarter. 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, based on data from the ECI, are published in a
separate news release titled "Employer Costs for Employee Compensation" (ECEC). These releases are
issued 3 months after the reference period. The ECEC release dates are available at
www.bls.gov/schedule/2017/home.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. 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-