Sampling and Collection in the Occupational Employment Statistics (OES) Program

1
Sampling and Collection in the Occupational
Employment Statistics (OES) Program

• Dixie Sommers and Laurie Salmon
• Occupational Information Development Advisory
  Panel
• May 4, 2011

2
Overview

• Data available from OES
• Uses and users of OES data
• Standard classifications used
• OES sample design
• OES survey operations
• OES estimation methods
• Special OES tabulations for ONET

3
Data available from OES
4
Occupational Employment Statistics

• Employment and wages for over 800 occupations
• Cross-industry estimates for
• The Nation
• States, District of Columbia, and selected
  territories
• Over 580 metropolitan and nonmetropolitan areas
• National estimates by specific industries
• Estimates by ownership
• Published annually with May reference date
• May 2010 data to be published May 17, 2011

5
Data items available

• Employment
• Hourly and annual mean wages
• Hourly and annual wages by percentile
• 10th, 25th, median, 75th, 90th percentiles
• Measure of sampling error
• Employment and mean wage percent relative
  standard errors (PRSEs)

6
Uses and users

• Employers and Human Resources professionals
• Compare pay to data for their industry or area
• Understanding occupational employment and wages
  in making location and expansion decisions
• Academic researchers
• Understanding the structure of the labor market
• Understanding wages
• Media and general public

7
Uses and users

• Career and job search information
• Students and job seekers
• Guidance and career counselors
• Policy and program uses
• E.g., wages for Foreign Labor Certification
• Staffing patterns uses
• Preparing employment projections
• ONET sampling design to identify industries with
  concentrations of employment in occupations being
  surveyed

8
Standard classifications used
9
Industry classification

• North American Industrial Classification System
  (NAICS)
• Establishments are classified according to the
  goods or services the establishment produces
• Issued by Office of Management and Budget
• Jointly developed by U.S., Canada, and Mexico
• U.S. Economic Classification Policy Committee
  chaired by Census Bureau
• Revised every five years (2002, 2007, 2012)

10
Industry classification

• NAICS example

21 Mining, Quarrying, and Oil and Gas Extraction 21 Mining, Quarrying, and Oil and Gas Extraction 21 Mining, Quarrying, and Oil and Gas Extraction 21 Mining, Quarrying, and Oil and Gas Extraction 21 Mining, Quarrying, and Oil and Gas Extraction
211 Oil and Gas Extraction 211 Oil and Gas Extraction 211 Oil and Gas Extraction 211 Oil and Gas Extraction
2111 Oil and Gas Extraction 2111 Oil and Gas Extraction 2111 Oil and Gas Extraction
21111 Oil and Gas Extraction 21111 Oil and Gas Extraction
211111 Crude Petroleum and Natural Gas Extraction
211112 Natural Gas Liquid Extraction
11
Occupational classification

• Standard Occupational Classification (SOC)
• Workers and jobs are classified into occupations
  based on the work performed
• Issued by Office of Management and Budget
• Standard Occupational Classification Policy
  Committee chaired by BLS
• Established SOC Classification Principles and
  Coding Guidelines
• Revised 2000 and 2010
• Next revision planned for 2018

12
Occupational classification

• 2010 SOC structure

23 Major groups 23 Major groups 23 Major groups 23 Major groups
97 Minor groups 97 Minor groups 97 Minor groups
461 Broad occupations 461 Broad occupations
840 Detailed occupations
13
Occupational classification

• SOC Example

Major group 41-0000 Sales and related occupations 41-0000 Sales and related occupations 41-0000 Sales and related occupations 41-0000 Sales and related occupations
Minor group 41-2000 Retail sales workers 41-2000 Retail sales workers 41-2000 Retail sales workers
Broad occupation 41-2020 Counter and rental clerks and parts salespersons 41-2020 Counter and rental clerks and parts salespersons
Detailed occupations 41-2021 Counter and rental clerks Receive orders, generally in person, for repairs, rentals, and services. May describe available options, compute cost, and accept payment.
Detailed occupations 41-2022 Parts salespersons Sell spare and replacement parts and equipment in repair shop or parts store.
14
Occupational classification

• SOC Manual provides approved modifications to the
  structure
• Delineation below the detailed occupation level
  permitted
• Add digits to the code
• 11-3031 Financial Managers
• 11-3031.01 Treasurers and Controllers
• OMB recommends that those needing extra detail
  use the ONET structure

15
Occupational classification

• All Federal agencies publishing occupational data
  for statistical purposes required to use SOC
• Increases data comparability across Federal
  programs
• SOC developed for statistical purposes only
• Non-statistical purposes play no role in SOC
  development
• OMB will not modify the SOC to meet requirements
  of non-statistical programs

16
Using industries and occupations together

• The combination of industry and occupation can
  further define the work
• E.g., retail salesperson may work selling cars
  and may need to drive. Others may work in stores
  and need to stand.
• OES provides these data
• Distribution of an occupations employment by
  industry
• Distribution of an industrys employment by
  occupation (staffing pattern)

17

• OES methodology
• Sample design
• Data collection cycle
• Estimation

18
OES sample design

• Sampling frame
• Unemployment insurance list of employers
• Covers 98 percent of wage and salary jobs
• Industry, county and employment level for each
  establishment
• Supplemented by other sources for industries not
  covered by state unemployment insurance
• Mainly Federal government and railroads
• Universe and sample sizes
• Universe size of about 8 million establishments
• 1.2 million establishments in OES sample

19
OES sample design

• Sample stratification
• By metropolitan and non-metropolitan area
• By industry strata
• Generally 4-digit NAICS, some 5-digit NAICS
• By ownership for certain sectors
• Education and hospitals by state government,
  local government, and private ownership

20
OES sample design

• Sample allocation for each stratum
• Include all large establishments
• Certainty units
• Improves sample efficiency
• For all other units
• Based on expected variability and stratum size
• Minimum number of sample units

21
Data collection cycle

• Full sample collected over 3-year cycle
• Two collection panels per year
• Reference dates of May and November

22

• OES Survey Operations
• OMB clearance
• Operational structure
• Data collection and processing

23
OMB clearance

• OMB clearance to conduct the survey
• Requires
• Description of purpose and uses
• No duplication of other federal data sources
• Detailed sample description
• Description of respondent burden hours and cost
• Response rate targets
• Use of standard classification systems
• Description of collection methods
• Public comment periods

24
Operational structure

• Federal-State Cooperative Program
• BLS National and Regional offices
• State Workforce Agencies
• BLS responsibilities
• Concepts and procedures
• Sample design and selection
• Survey form design, printing and mailing
• Data capture and estimation systems
• Produce and publish estimates
• Data quality assurance
• Training and technical assistance
• Confidentiality policy and procedures
• Funding

25
Operational structure

• State workforce agency responsibilities
• Address refinement of sample units
• Data collection, including non-response follow-up
• Data processing and editing
• Occupational coding
• Estimates review and publication
• Protect data confidentiality

26
OES survey forms

• Developed through cognitive and field testing
• For all types of establishments
• Verify known information about the establishment
  employment, industry
• Request contact information for follow-up

27
OES survey forms

• Structured forms
• For medium size and larger establishments
• Specific to individual industries or groups of
  industries
• Lists occupations commonly found in the industry
• Includes occupation definitions
• Employer determines how SOC codes relate to
  establishments job categories

28
OES survey forms

• Unstructured forms
• For smaller establishments
• For all non-responding establishments in the
  third follow-up mailing
• Open-ended format
• No occupations listed on form
• Employer reports by own job categories
• Data coded to SOC by state or regional office
  staff

29
OES survey forms

• All forms
• Request employment in the occupation by wage
  intervals
• Wage intervals used to estimate wage means,
  medians, and percentiles

30
Data collection

• Mailing
• Includes form, letter, information sheet
• Second and third mailings to non-respondents
• Response mode options
• Complete paper form and mail back
• Complete form online
• Phone response
• Fax response
• Provide electronic payroll file (mail or email)
• Provide paper payroll listing

31
Data collection

• Improving response rates
• Pre-notification postcards
• Telephone follow-up
• Flexibility in reporting mode
• Web site for respondents
• Why respondents data are important
• Provide publications
• Confidentiality pledge
• Training data collectors on reluctance aversion

32
Data collection

• Response mode varies by establishment size
• Response rates for most recent panel
• 77.7 percent of establishments
• 69.5 percent of employment

33
OES estimation methods

• Use three years of data (six panels)
• May 2010 data based on these panels
• May 2010 November 2009
• May 2009 November 2008
• May 2008 November 2007
• Employment estimation
• Sample weight adjustment
• Benchmarked to industry employment level from
  external source

34
OES estimation methods

• Wage estimation using wage interval data
• BLS National Compensation Survey data used to
  estimate mean wages in each interval
• BLS Employment Cost Index used to age wages
  collected in earlier panels
• Wages estimation using wage rate data
• Direct computation of means, medians, and
  percentiles
• Wage rate data for in certain sectors
• Federal government, U.S. Postal Service
• State government in many states

35
Special tabulations for ONET

• Distribution of occupational employment by
  6-digit NAICS
• More detailed than published OES data
• Shows industries and areas with most employment
  in the occupation
• Useful for targeting sample selection on
  industries where occupation known to exist

36
Dixie SommersAssistant Commissioner, Office of
Occupational Statistics and Employment
Projections 202-691-5701Sommers.Dixie_at_bls.gov
Laurie SalmonSupervisory Economist, Division of
Occupational Employment Statistics
202-691-5701Salmon.Laurie_at_bls.gov
www.bls.gov/oes