Handbook of Methods Occupational Requirements Survey Design

Occupational Requirements Survey (ORS) data are collected from a national probability sample of establishments and occupations. Probability samples are subject to sampling and nonsampling errors, which are discussed in the calculation section.

Establishment selection

The ORS program uses a probability-proportional-to-size (PPS) technique to select a sample of private industry establishments as well as state and local government establishments from across the nation. The larger the establishment's employment size, the greater its chance of being selected. Establishments from all 50 states and the District of Columbia are eligible for selection.

The third wave total sample size will include approximately 75,000 establishments. Private industry establishments account for 85 percent (63,750) of the total, and state and local government establishments accounts for the remaining 15 percent (11,250). A portion of the total sample size will be independently sampled each year from private industry and state and local government establishments in proportion to their representation in the full wave. When establishments are selected in more than one sample, collection is only performed once in that wave.

The sampling design for the private industry sample is a two-stage stratified sample of private industry establishments and occupations within selected establishments. Forty strata are formed by the cross-classification of the predicted presence and absence of preselected priority occupations in establishments, four U.S. census regions (Midwest, Northeast, Southeast, and West), and aggregate industry (education services, financial activities, goods producing, healthcare and social assistance, and service providing). For the purposes of sample selection, priority occupations have at least 25,000 workers nationally based on the May 2020 Occupational Employment and Wage Statistics (OEWS) estimates with a maximum high school education required and with low specific vocational preparation requirements. ORS currently samples state and local government occupations at the time of collection. An occupation-level frame is not used for these establishments, so priority occupation status does not apply. Each priority occupation is listed by its Standard Occupational Classification (SOC) code in exhibit 1.

Each sampled establishment has an assigned 6-digit industry code from the North American Industry Classification System (NAICS). When a single physical location encompasses two or more distinct economic activities, the industry code assigned is based on the establishment's principal product or products, whether produced or distributed, or the principal services rendered by the establishment. When determining the principal product or service rendered, employment is used to determine the primary business activity and assign an industry code. When the primary activity cannot be determined by employment, then it is determined based on the revenue generated.

The sampling frame, or universe, is the list of establishments from which the survey sample is selected. The ORS establishment sample is drawn from the Quarterly Census of Employment and Wages (QCEW)^⁠⁠⁠⁠ and units reporting to the Railroad Retirement Board.^⁠⁠1

Job selection

U.S. Bureau of Labor Statistics (BLS) field economists use a three-step process to select and classify jobs for which data are to be collected from the sampled establishment.

Step 1

The first step in the process differs depending on establishment ownership. For private industry establishments, the ORS utilizes an occupational sample that is drawn from a modeled occupational frame created by the OEWS program.^⁠⁠2 This frame informs the selection of occupations within establishments by joining industry information from the QCEW with occupational information from the OEWS. ORS currently samples state and local government occupations at the time of collection. An occupation-level frame is not used for these establishments, so priority occupation status does not apply.

Field economists are given a prioritized list of 6-digit occupational codes for each private industry sampled establishment. The number of jobs selected for data collection is based on the establishment's employment size at the time the sample was drawn, according to the criteria listed in exhibit 2, and the projected number of occupations at the establishment from the modeled occupational frame. These occupations are listed in a prioritized order for collection. Field economists determine whether any of the listed occupations exist in the sampled establishment. Field economists stop matching when they reach the targeted number of selected jobs or when the end of the list is reached. This job selection method is used to ensure that occupations with lower probability of selection are included in the survey. If none of the occupations on the prioritized list are present in the establishment, the field economist collects data by using probability sampling of occupations (PSO). The field economist uses the PSO technique to randomly select jobs for which data are to be collected. This process ensures that the probability of selecting a given job is proportional to the number of workers in the job at the establishment. This process is used to select jobs from state and local government establishments.

Step 2

Field economists classify the sampled jobs into occupations based on the workers' actual job duties and responsibilities, not based on their job titles or specific education. For example, an employee trained as an engineer, but is working as a drafter, is considered a drafter. Field economists classify employees who perform the duties of two or more distinct occupations as working in the occupation that requires the highest level of skill or in the occupation in which the employee spends the most time if there is no measurable difference in skill requirements. Each sampled job is classified by the Standard Occupational Classification (SOC) system at the 6-digit level of detail.

ORS classifies sampled jobs found in establishments into the most detailed occupational code available. Federal statistical agencies are mandated to use the SOC system for the purpose of collecting, calculating, or disseminating occupational or labor market data.

Step 3

Field economists obtain work status (full time or part time) and work schedule for the selected job. The work status is based on the responding establishment's definition of full time and part time and is not based on an hour threshold. The work schedule is used to determine the duration levels and reflects the usual expected hours in a day, days in a week, and weeks in the year. The job requirements in the establishment are for all workers in the selected job with the same work status and work schedule. For definitions of occupational characteristics, see the concepts section.