Occupational Employment and Wages Technical Note

Technical Note

Scope of the survey

The Occupational Employment Statistics (OES) survey is a semiannual survey measuring
occupational employment and wage rates for wage and salary workers in nonfarm
establishments in the United States. The OES data available from BLS include cross-
industry occupational employment and wage estimates for the nation; over 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, two
semiannual panels of approximately 200,000 sampled establishments are contacted, one
panel in May and the other in November. Responses are obtained by mail, Internet or
other electronic means, email, telephone, or personal visit. The May 2016 estimates
are based on responses from six semiannual panels collected over a 3-year period:
May 2016, November 2015, May 2015, November 2014, May 2014, and November 2013. The
overall national response rate for the six panels, based on the 50 states and the
District of Columbia, is 73 percent based on establishments and 69 percent based on
weighted sampled employment. The unweighted employment of sampled establishments
across all six semiannual panels represents approximately 58 percent of total
national employment. 

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 included. 

For more information about the SOC system, please see the BLS website at
www.bls.gov/soc/.

The industry coding system

The May 2016 OES estimates use the 2012 North American Industry Classification
System (NAICS). For more information about NAICS, see the BLS website at
www.bls.gov/bls/naics.htm.

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.

Concepts

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
most state governments. For the remaining establishments, the OES survey data are
placed into 12 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. Some 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 from
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 2015 and May 2016 employment) from the BLS
Quarterly Census of Employment and Wages to employment totals from the OES survey.

Special procedures for the May 2016 estimates

In May 2013, the Quarterly Census of Employment and Wages program, from which the
OES sample is drawn, began coding some establishments that were historically found
in private households (NAICS 814110) to services for the elderly and persons with
disabilities (NAICS 624120). 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 five most recent of the six survey panels used to produce the
May 2016 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 www.bls.gov/oes/current/methods_statement.pdf. 



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Last Modified Date: March 31, 2017