Occupational Employment and Wages Technical Note

Technical Note

Scope of the survey

The Occupational Employment Statistics (OES) survey is a semiannual mail survey
measuring occupational employment and wage rates for wage and salary workers in
nonfarm establishments in the United States. OES data available from BLS include
cross-industry occupational employment and wage estimates for the nation; nearly
650 areas, including states and the District of Columbia, metropolitan statistical
areas (MSAs), metropolitan divisions, nonmetropolitan areas, and territories;
national industry-specific estimates at the NAICS sector, 3-, 4-, and selected
5- and 6-digit industry levels; and national estimates by ownership across all
industries and for schools and hospitals.

The OES survey is a cooperative effort between BLS and the State Workforce
Agencies (SWAs). BLS funds the survey and provides the procedures and technical
support, while the State Workforce Agencies collect most of the data. OES
estimates are constructed from a sample of about 1.2 million establishments.
Each year, forms are mailed to two semiannual panels of approximately 200,000
sampled establishments, one panel in May and the other in November. May 2014
estimates are based on responses from six semiannual panels collected over a
3-year period: May 2014, November 2013, May 2013, November 2012, May 2012, and
November 2011. The overall national response rate for the six panels is 74.3
percent based on establishments and 70.5 percent based on weighted sampled
employment. The unweighted employment of sampled establishments across all
six semiannual panels represents approximately 57.1 percent of total national
employment. (Response rates are slightly lower for these estimates due to the
federal shutdown in October 2013.)

The occupational coding system

The OES survey categorizes workers into 821 detailed occupations based on the
Office of Management and Budget’s 2010 Standard Occupational Classification (SOC)
system. Together, these detailed occupations make up 22 of the 23 SOC major
occupational groups. Major group 55, Military Specific Occupations, is not

For more information about the SOC system, please see the BLS website at

The industry coding system

The May 2014 OES estimates use the 2012 North American Industry Classification
System (NAICS). For more information about NAICS, see the BLS website at

The OES survey excludes the majority of the agricultural sector, with the exception
of logging (NAICS 113310), support activities for crop production (NAICS 1151), and
support activities for animal production (NAICS 1152). Private households (NAICS 814)
also are excluded. OES federal government data include the U.S. Postal Service and
the federal executive branch only. All other industries, including state and local
government, are covered by the survey. 

Survey sample

The OES survey draws its sample from state unemployment insurance (UI) files.
Supplemental sources are used for rail transportation (NAICS 4821) and Guam
because they do not report to the UI program. The OES survey sample is stratified
by metropolitan and nonmetropolitan area, industry, and size.

To provide the most occupational coverage, larger employers are more likely to be
selected than smaller employers. A census is taken of the executive branch of the
federal government, the U.S. Postal Service, and state government.


Occupational employment is the estimate of total wage and salary employment in an
occupation. The OES survey defines employment as the number of workers who can be
classified as full- or part-time employees, including workers on paid vacations or
other types of paid leave; workers on unpaid short-term absences; salaried officers,
executives, and staff members of incorporated firms; employees temporarily assigned
to other units; and employees for whom the reporting unit is their permanent duty
station, regardless of whether that unit prepares their paycheck. The survey does
not include the self-employed, owners and partners in unincorporated firms, household
workers, or unpaid family workers.

Wages for the OES survey are straight-time, gross pay, exclusive of premium pay. Base
rate; cost-of-living allowances; guaranteed pay; hazardous-duty pay; incentive pay,
including commissions and production bonuses; and tips are included. Excluded are
overtime pay, severance pay, shift differentials, nonproduction bonuses, employer cost
for supplementary benefits, and tuition reimbursements.

OES receives wage rate data for the federal government, the U.S. Postal Service, and
some state governments. For the remaining establishments, the OES survey collects
wage data in 12 intervals. For each occupation, respondents are asked to report the
number of employees paid within specific wage intervals. The intervals are defined
both as hourly rates and the corresponding annual rates, where the annual rate for an
occupation is calculated by multiplying the hourly wage rate by a typical work year
of 2,080 hours. The responding establishments are instructed to report the hourly rate
for part-time workers, and to report annual rates for occupations that are typically
paid at an annual  rate but do not work 2,080 hours per year, such as teachers, pilots,
and flight attendants. Other workers, such as some entertainment workers, are paid
hourly rates, but generally do not work 40 hours per week, year round. For these
workers, only an hourly wage is reported.

Estimation methodology

The OES survey is designed to produce estimates by combining six panels of data collected
over a 3-year period. Each OES panel includes approximately 200,000 establishments. The
full six-panel sample of nearly 1.2 million establishments allows the production of
estimates at detailed levels of geography, industry, and occupation.

Wage updating. Significant reductions in sampling errors are obtained by combining six 
panels of data, particularly for small geographic areas and occupations. Wages for the
current panel need no adjustment. However, wages in the five previous panels need to be
updated to the current panel's reference period.

The OES program uses the BLS Employment Cost Index (ECI) to adjust survey data from prior
panels before combining them with the current panel's data. The wage updating procedure
adjusts each detailed occupation's wage rate, as measured in the earlier panel, according
to the average movement of its broader occupational division.

Imputation. About 25 percent of establishments do not respond for a given panel. For most
employers, a "nearest neighbor" hot deck imputation procedure is used to impute missing
occupational employment totals. A variant of mean imputation is used to impute missing 
wage distributions. In some cases, data for current panel nonrespondents are available
for earlier panels. In those cases, the older data may be used and aged to represent the
current reference period. 

Weighting and benchmarking. The sampled establishments are weighted to represent all
establishments for the reference period. Weights are further adjusted by the ratio of
employment totals (the average of November 2013 and May 2014 employment) from the BLS
Quarterly Census of Employment and Wages to employment totals from the OES survey.

Changes and special procedures for the May 2014 estimates

In previous sets of estimates, local government gambling establishments and casino hotels
were included in OES-defined industry 999300 Local Government. Beginning with the May 2014
estimates, local government gambling establishments and casino hotels will be included in
NAICS 7132 Gambling Industries and 72112 Casino Hotels, respectively, along with private
sector establishments in those industries.

The Quarterly Census of Employment and Wages program, from which the OES sample is drawn,
has recently begun coding some establishments that were historically found in NAICS 814110
Private Households to NAICS 624120 Services for the Elderly and Persons with Disabilities.
Private households are out of scope for OES, so this shift caused a scope increase for OES
in NAICS 624120. Because this scope increase affected only the most recent (May 2014) of
the six survey panels used to produce the May 2014 OES estimates, the units that shifted
industries were removed from the survey data and not used in estimation.

For more information

Answers to frequently asked questions about the OES data are available at
www.bls.gov/oes/oes_ques.htm. Detailed technical information about the OES survey
is available in the Survey Methods and Reliability Statement on the BLS website at

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Last Modified Date: March 25, 2015