Employment Cost Index technical note
Last Modified Date: April 30, 2015
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 BLS Handbook of Methods,
Chapter 8, “National Compensation Measures,” Bureau of Labor Statistics, on the Internet at
Data for the March 2015 reference period were collected from a probability sample of approximately
37,400 occupational observations selected from a sample of about 8,600 private industry establishments
and approximately 8,900 occupational observations selected from a sample of about 1,500 state and
local government establishments that provided data at the initial interview.
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). The next ECEC
release is scheduled for 10:00 a.m. (EDT), Wednesday, June 10, 2015. 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.
Seasonal Adjustment Revisions
Each year data series are reviewed for seasonal patterns. When seasonality is found, data are published
as a seasonally adjusted series. Based on this review for 2015, the seasonally adjusted private industry
service occupations wages and salaries series was dropped, while a seasonally adjusted series for private
industry nursing and residential care facilities wages and salaries was added. Historical data for the latter
series, beginning with March 2010, are now available. For additional information regarding the annual
seasonal adjustment process please visit www.bls.gov/ncs/ect/ectsfact.htm.