INTRODUCTION

Because the risk factors that cause, contribute to, or aggravate work-related musculoskeletal disorders (MSDs) among workers are associated with the conditions of work in all industries in the general industry sector, the scope of the proposed rule encompasses all of general industry. Because of the breadth of the standard, and because the coverage of the standard matches the categories of the Standard Industrial Classification (SIC) code system, OSHA has characterized affected establishments and employers in terms of their three-digit SIC codes. This approach allows OSHA to use standard statistical sources to characterize the affected establishments and industries, while at the same time allowing for the subdivision of affected establishments into nearly 350 separate industrial categories. In addition, to facilitate more accurate cost analysis for smaller employers and the preparation of an Initial Regulatory Flexibility Analysis (see Chapter VII), OSHA has separated affected smaller employers into two size classes: very small employers (those with 19 or fewer employees), and employers that fall under the Small Business Administration's (SBA) size criterion for small entities (businesses) in a given industry.

This chapter of the economic analysis explains the data sources and methodologies used to characterize the establishments and employers potentially affected by this rule. It provides the information OSHA uses in the benefits, costs of compliance, economic feasibility, economic impact, and initial regulatory flexibility analysis chapters of this economic analysis.

This economic analysis is based on data on employers, employees, wage and turnover rates, and information about the risk of MSDs, including the risk associated with manual handling and manufacturing production operations. Determining the number of establishments and employees within the scope of various provisions of the standard at any given time is complicated by the design of the standard itself. All establishments in general industry are potentially affected by the rule in the sense that if an MSD occurs, the employer will have to determine if the MSD is a covered MSD, as defined by the standard and as applicable to the particular job (manual handling, manufacturing, or elsewhere in general industry). The first step in this Industrial Profile chapter, therefore, is to determine the number of establishments and employees in general industry. However, in the typical year, most establishments will not be within the scope of the rule (because their employees have not experienced a covered MSD.) Only general industry establishments with employees engaged in manual handling or manufacturing operations, or general industry employers whose employees have or have had a covered MSD, will be within the scope of the rule at any given time. In addition, only general industry establishments where employees have or will experience a covered MSD will need to have a full program under the rule. (Even then, the full program will apply only to employees with the same job as the employee who had a covered MSD). The industrial profile therefore needs to identify the number of general industry establishments with employees engaged in manufacturing operations or manual handling, as well as the number of other general industry establishments where employees have or will experience a covered MSD, to determine the number of establishments within the scope of the rule. Estimates of the number of employers and employees subject to the full program required by the proposed standard depend on the results of calculations that are explained in detail in the Benefits chapter (Chapter IV).

Specifically, the data presented in this Industrial Profile chapter of the analysis are:

• Number of potentially affected establishments (by size class and industry);

• Number of employees in potentially affected establishments (by size class and industry);

• Extent of manufacturing operations (by industry);

• Extent of manual handling operations (by industry);

• MSD rates (by size class and industry);

• Number of establishments with covered MSDs (by industry);

• Number of establishments within the scope of the standard (by industry); and

• Wages and turnover rates (by industry).

The sources of data and key information for each of these characteristics are provided in the remaining sections of this chapter. Information about current industry compliance rates is presented in Chapter V, which estimates the costs of compliance, and financial data on affected firms and establishments are presented in Chapter VII, which presents economic impacts and the Initial Regulatory Flexibility Analysis.

Number of Potentially Affected Establishments and Employees

This section explains OSHA's derivation of the number of potentially affected employees and establishments, i.e., the number of employees and establishments that could, under some circumstances, come within the scope of the rule. As will be seen in later chapters, most potentially affected establishments will not come within the scope of the rule in any given year.

Estimates of the number of employees and the number of establishments subject to the proposed rule were derived primarily from U.S. Bureau of the Census sources. Private sector employment and establishment data for 1995 were taken from County Business Patterns (1995). County Business Patterns provides employment data for most business establishments that have one or more paid employees. These were the most current and comprehensive sources of employment and establishment data available at the time this preliminary economic analysis was initiated.

The employee and establishment data in County Business Patterns were distributed among establishments, based on the number of employees per establishment, using the following size classifications:

• 1-19 employees;

• 20-99 employees;

• 100-499 employees; and

• 500 or more employees.

All categories were aggregated to obtain an estimate of the total number of establishments and employees in each size classification. The Agency also aggregated employment data for each 3-digit industry according to the applicable SBA size criterion for small businesses in that industry. Where more than one SBA size class criterion applied within a three digit SIC code, OSHA applied the criterion for the largest industry within the SIC code to all of the industries within the SIC.

Certain work operations within the economy are not covered by the proposed rule and, therefore, are excluded from this economic analysis. The major SIC groups (i.e., 2-digit SIC code industries) excluded are: agricultural production (SIC codes 01, 02, and 078); mining, except oil and gas production (SIC codes 10, 12, and 14); construction (SIC codes 15, 16, and 17); and railroad and marine transportation (SIC codes 40 and most of 44). In addition, the maritime industries directly covered by OSHA standards (shipyards, marine terminals and longshoring operations) are excluded from the scope of the proposed ergonomics standard. These industries are classified in the four-digit SIC 3731, Shipbuilding and Repairing, and SIC 4491, Marine Cargo Handling. Also excluded from the scope of the rule are state and local government employees and establishments in non-State-plan states.

When relatively few establishments exist within a size classification for a particular industry, the Bureau of the Census does not disclose data on the number of employees in that size classification, in order to protect the identity of the establishment(s). For example, because there are only two establishments with 1,000 or more employees in the Pottery and related products industry (SIC code 326), employment in that size category is not disclosed. To provide additional protection from disclosure, data on employment for establishments in SIC 326 with 1-4 employees are also not disclosed, although the number of such establishments is disclosed. The Bureau of the Census practice of excluding employment data from at least two size categories of establishments is followed if data from one size category are withheld.

Of the 404 industries in the U.S. economy reported at the 1-, 2-, and 3-digit SIC code level in County Business Patterns, entries for 198 industries did not disclose data for two or more sizes of establishments. Although most of this non-disclosure was at the industry group (3-digit) level, entries for eight major groups (2-digit level) included undisclosed data. Most commonly, the Bureau of the Census' disclosure concerns were triggered by the presence of a few large establishments in an industry. Data on employment for establishments with 1,000 or more workers were not disclosed for 85 of the 353 industries, while for establishments with 500 to 999 employees, employment data were not disclosed for 95 industries. Together these two largest size categories accounted for 180 of the 183 sectors for which data were not disclosed.

Many of the costs associated with the proposed rule are estimated on a per-employee basis. Lack of data on the number of employees would therefore make these cost estimates less precise. To overcome this methodological limitation, OSHA used interpolation to estimate the number of employees in establishments of various size classes for which Bureau of the Census data were unavailable. Data were interpolated based on the average number of employees in establishments of that size class in other industries and on total employment in the industry for which size class data were interpolated. The interpolation methods used are described in detail in Appendix II-A to this chapter.

Table II-1 shows the resulting estimates of the number of potentially affected establishments, by size class and industry, and Table II-2 shows the resulting estimates of the number of potentially affected employees, by size class and industry. These tables show that the rule would potentially cover about 93 million workers in about 5.9 million establishments, although the number of employees and establishments covered in any given year would be substantially fewer.

Manufacturing Operations

OSHA estimated the number of general industry establishments in which employees engage in manufacturing operations as all establishments in the manufacturing SIC codes, 20 through 39. The number of establishments in these SIC codes is shown in Table II-1. The number of employees engaged in manufacturing operations was estimated from the number of production workers in manufacturing operations, as given in BLS's Employment and Earnings, January 1997. Table II-3 shows the number of employees engaged in manufacturing operations, by 3-digit SIC industry. OSHA estimates that there are 11.7 million such employees.

Manual Handling

To estimate the number of employees and establishments performing manual handling, OSHA used data from its 1993 nationwide ergonomics survey⁽¹⁾ (ERG 1999). Specifically, question 33 of the survey asked whether employees in a given occupation lifted or lowered more than 25 lbs. For the manufacturing sector, SICs 20-39, those occupations other than manufacturing production occupations were examined to determine whether they involved manual handling (to avoid double-counting employees in manufacturing production jobs who might also do manual handling). The results are shown in Table II-4, which shows that an estimated 10.4 million employees in general industry engage in manual handling. OSHA believes that this number of manual handling employees is likely to be an overestimate because the 25-lb lift criterion used in the 1993 survey is substantially broader than the manual handling definition used in the proposed rule. To the extent that this is the case, both the costs and benefits of this rule will be overstated.

MSD Rates

To develop estimates of the number of employer-reported MSDs by industry, OSHA worked with the BLS to define MSDs using three BLS databases on the characteristics of recordable injuries and illnesses. The methodology used and the definition of MSDs developed for this purpose are described in detail in the Preliminary Risk Assessment section of the preamble to this standard. Basically, OSHA defined MSDs as strains, sprains and tears; back pain; soreness and hurt back; carpal tunnel syndrome; hernia; musculoskeletal disorders and connective tissue diseases and disorders that are caused by overexertion, repetition, or bodily reactions (such as bending or crawling). This definition is designed to include only those kinds of injuries and illnesses covered by the proposed ergonomics standard and to ensure that such injuries and illnesses are only included within the definition when they involve the risk factors that the proposed standard is intended to address (such as forceful exertion, repetition, and awkward postures). Thus, for example, this approach to defining MSDs using BLS data includes back strain due to forceful exertion, but does not include back strain caused by slips, trips or falls, or by motor vehicle accidents. Using this definition, BLS provided OSHA with data for the years 1993 to 1996 on the number of MSDs by SIC code (Ex. 26-1413). The 1996 data reported by employers were used for this Preliminary Economic Analysis. (Similar detail is not yet available for the 1997 BLS data.)

Several steps were necessary to use these data to provide information on benefits, costs, and economic impacts at the three-digit SIC code level of analysis. First, in some cases BLS data on MSDs are not available at the three-digit level of analysis. In these cases, OSHA assumed that the three-digit SIC code would have the same average MSD rate as the two-digit SIC code of which it is a part. Second, analysis of the proposed ergonomics standard requires estimates of the total number of MSDs (both lost workday and non-lost workday), whereas BLS data permit estimation only of the number of MSDs involving at least one day away from work. To estimate the total number of MSDs, OSHA relied on BLS data and multiplied the number of MSDs involving at least one day away from work for each industry times the ratio of all injuries and illnesses to injuries and illnesses involving days away from work for that particular industry. This estimate of the total number of MSDs by three-digit SIC code is given in Table II-5. OSHA estimates that about 2 million work-related MSDs (both lost workday and non-lost workday MSDs) occur in general industry every year.

Finally, OSHA computed the rate of MSDs as the estimated number of MSDs occurring in a three-digit SIC code industry divided by the number of employees in that industry, as derived in the previous section estimating the number of potentially affected employees. These rate are shown, per 10,000 workers per year, in Table II-5. They range from 8 MSDs per 10,000 workers in SIC 866, Religous orgnaizations, to 1,448 MSDs per 10,000 workers in SIC 253, Public building & related furniture. These figures differ from those presented in the Preliminary Risk Assessment because the numerator used here includes estimates of the number of non-lost workday MSDs and the denominator is based on County Business Pattern rather than BLS data.

In both the cost and benefits analyses, for industries consisting solely of public employees, which are not covered by the BLS data, OSHA estimated the MSD injury and illness rates based on those for similar private sector industries, e.g., government social services establishments were assumed to have the same MSD injury and illness rate as private sector social services establishments, government police forces were assumed to have the same MSD injury and illness rates as private guard and security services, and so on.

Number of Establishments with a Covered MSD

Estimates of the probability of an establishment having at least one covered MSD, and thus requiring a full program under the standard in a given year, were derived by estimating the probability of having an employee with an MSD in the average industry establishment having 1-19, 20-99, 100-499, or 500 or more employees:

1- (1-employee MSD rate)^{(# of employees per establishment)}

To identify the potential scope of the proposed standard for the purposes of this industrial profile, OSHA assumes that all recordable MSDs will trigger a full program. This assumption results in an overestimate of the number of establishments that will be required to have full programs, because some number of recordable MSDs will not, in fact, pass the proposed standard's screening criteria for covered MSDs. Table II-6 shows the number of establishments OSHA estimates will be required to have a full program because at least one employee will experience a covered MSD in the first year of the standard's full implementation; about 1.9 million establishments are in this group.

Total Number of Establishments in the Scope of the Proposed Standard in the First Year

Based on the results presented above, with respect to general industry establishments with employees engaged in manufacturing operations or in manual handling, and in other general industry establishments in which employees are projected to experience a covered MSD, Table II-6 shows the total number of establishments in the scope of the standard in the first year after the standard is implemented. The total number of such establishments is 1.9 million in the first year after implementation, less than one-third of the establishments potentially covered by the proposed standard (see Table II-1).

Wage and Turnover Rates

Labor costs account for a significant part of the total costs of the proposed rule. Average hourly wage rates were determined from the Bureau of Labor Statistics database reporting 1996 average earnings data and published in Employment and Earnings and on the BLS Web site (BLS, 1996). These average total wage rates are presented in Table II-7. The labor rates and fringe benefits for these categories of personnel are used throughout the cost analysis.

The fringe rate used in the analysis is from the Bureau of Labor Statistics News, October 10, 1997, Chart A (BLS, 1997). The Bureau of Labor Statistics estimates that fringe benefits are equal to 39 percent of the average base labor rate per hour for American workers. Therefore, the hourly rate per employee used in this analysis is 139.08 percent of the base labor rate per hour for employees.

Turnover rates among establishments are also used in the cost analysis. Turnover can be a key element in the costs of training for both managers and employees. For example, if an employer has 100 employees and a turnover rate of 10% per year, the costs of initial training include both the costs of providing initial training to 100 employees and the annual costs of providing 10 employees per year (10 percent of 100) with such training. Turnover rates for 1996, by industry sector, were available from the Bureau of National Affairs. These 2-digit SIC turnover rates were applied to all 3-digit SIC classifications within the 2-digit industry.

The economic analysis also relies on information from OSHA's 1993 ergonomics survey for current industry baseline information, by 3-digit SIC, for two issues that are key to the analyses of the costs of compliance and the benefits of the proposed rule. These issues are the extent to which employers have implemented ergonomics engineering controls in response to their identification of ergonomics hazards, and the extent to which they have "light duty," or alternative duty, jobs available for employees placed on restricted work (Table II-8). These current industry practice baselines were taken into account in deriving both costs and benefits.

The economic analysis also requires a determination of the number of workers who share the same job. David Alexander of Auburn Engineers told OSHA that he found that in a 1000 employee plant, he would typically find 200 to 300 distinct jobs. This suggests that in large manufacturing establishments, between 3 and 5 employees share jobs with similar risk factors, and thus would be covered if an MSD occurred to any worker with that job. The number of employees with the same job would normally be smaller in smaller establishments, but may be larger in some non-manufacturing environments.

In order to estimate the average number of employees with the same job by industry, OSHA referred back to its 1993 ergonomics survey (ERG, 1999), and examined the number of processes and occupational titles per establishment. OSHA assumed that for a job to be the same, it would need to involve the same occupational title. In the smallest establishments, those with 1-19 employees, the number of employees with the same job was estimated by looking at average employment per establishment and dividing by the average number of occupational titles per establishment. In these small establishments, employees with the same occupational title may perform tasks in several processes. For establishments with more than 20 employees, OSHA assumed that employees in the same job would have the same occupational title and work on the same process. The estimated number of employees with the same job was therefore determined by dividing average employment by the average number of occupational titles and by the average number of processes. For the largest size class, establishments with more than 500 employees, the results of this calculation were divided by 3, because some processes and occupational titles with similar names may involve differences not noted on the survey. This methodology yielded results that were consistent with Mr. Alexander's estimates for large manufacturing establishments.

The results are shown in Table II-9.

This chapter has presented data on the number of establishments and employees potentially in the scope of the proposed ergonomics program standard, including those in the private and public sectors. It also estimated the number of workers engaged in manufacturing production jobs and in manual handling operations. In addition, the total MSD incidence rate per 10,000 full-time workers was presented by 3-digit SIC code. These data form the basis for the calculations used to derive the costs of compliance, benefits, and economic impacts of the proposed standard.

Bureau of Census, Department of Commerce, County Business Patterns, 1996.

Bureau of Labor Statistics, U.S. Department of Labor, Employment and Earnings, 1997.

Bureau of Labor Statistics, U.S. Department of Labor, News Release, October 10, 1997 (available to http://www.bls.gov/) (Ex. 26-1591)

Eastern Research Group. [ERG, 1999] Tabulations from OSHA's 1993 Ergonomics Survey Lexington, MA. 1999. (Ex. 26-1596).

Kearney/Centaur, "Summary of OSHA Expert Panel Meeting on Ergonomics," 1992. (Ex. 26-1594)

Washington Consulting Group, Documentation of OSHA Ergonomics Survey, 1994. (Ex. 26-1595)

A:  Interpolation Methods Used to Estimate Missing Data in County Business Patterns

B:  OSHA's Nationwide Ergonomics Telephone Survey

APPENDIX II-A: Interpolation Methods Used to Estimate Missing Data in County Business Patterns

The following approach was used to interpolate missing data in County Business Patterns:

1. For all establishments where employment data were not disclosed, employment was estimated by multiplying the number of establishments by the national average number of employees per establishments of the relevant size. For example, for establishments with 500-999 employees, the average establishment had 682 employees. If a sector had undisclosed data for 2 establishments with 500-999 employees, total employment at those 2 establishments was estimated at 1,364 employees (i.e., 682 X 2).

2. Using these estimates, total estimated employment for the sector was compared with actual total employment for the sector. Total employment for each sector is available from the County Business Patterns database, regardless of whether employment data for each size of establishment are disclosed. The difference between estimated and actual employment for the sector was determined.

3. The value of the difference between estimated and actual employment was added to or subtracted from one of the employment estimates for that sector so that estimated employment equaled actual employment. This adjustment to estimated employment was initially made to the employment total for the largest size of establishment for which employment was estimated. The new estimate of employment was tested to determine whether average employment per establishment remained within the bounds of the establishment size for the affected estimate. Thus, if this adjustment resulted in an average estimated employment of 537 employees for all establishments in the 500-999 employee size class, the adjusted estimate was considered acceptable. Alternatively, if this adjustment resulted in a new average estimated employment of 537 employees for all establishments in the 240-499 employee size class, the estimate was not considered acceptable. In the latter case, the difference between the estimated and actual employment was applied to a category of smaller establishments. The average employee per establishment figure was tested again. In no case was the difference between initially estimated employment and actual employment added to more than one category of establishments.

For every sector where these adjustments were made, total estimated employment equaled actual employment. The error in the estimate was limited to the distribution of employees among sizes of establishment. These adjustments applied only to private employment in SIC code sectors 20 through 89.

Appendix II-B: OSHA's Nationwide Ergonomics Telephone Survey Introduction

In preparation for this ergonomics program rulemaking, OSHA, along with its contractors, Eastern Research Group, Washington Consulting Group, and Kearney/Centaur, prepared and administered a survey to employers in 1993. The survey covered employers in almost all industries and was designed to determine the extent of their awareness of musculoskeletal problems and the kinds of ergonomic programs currently in place to address these problems. The results of the OSHA survey have been used to provide some of the information in this Preliminary Economic Analysis. This report describes the background of the survey collection effort and the survey data itself.

Background

In 1993, OSHA conducted a survey of 3,259 establishments to obtain industry-specific data concerning the prevalence of musculoskeletal risk factors and of ergonomic programs of various kinds. The purpose of the survey was to collect accurate and complete information on the extent of workplace exposure to those risk factors associated with musculoskeletal disorders and on efforts being taken by employers to reduce or eliminate these risk factors. The universe encompassed by the ergonomics survey included nearly all OSHA-regulated establishments in the United States.

OSHA followed a number of procedures to ensure the accuracy and effectiveness of its ergonomics survey. For example, at the outset of the project, OSHA convened a panel of experts to discuss the design of an ergonomics survey. These experts were drawn from many different fields, including ergonomics, occupational medicine, epidemiology, industrial hygiene, and engineering. The expert panel including representatives from industry, government, labor organizations, academia, and medicine.

A package of information was sent to panel members before they met. The package asked each expert to rate and rank 3-digit Standard Industrial Classification (SIC) codes with respect to the extent of musculoskeletal risk factors present in the industry represented by that SIC. The panel's objectives over the two-day meeting were to help target the survey to the affected industries, help develop a series of interview prompts based on occupational activities that would identify the hazardous occupation and processes in a given industry, identify solutions to reduce or eliminate exposure to the risk factors associated with musculoskeletal disorders, and provide guidance on other issues as they arose. The expert panel was also give a list of occupations, organized by 3-digit SIC, that had been selected from the Occupational Employment Survey conducted by the Bureau of Labor Statistics (BLS). The expert panel identified both the occupation and area of the body (upper extremity, lower back, or lower extremity) considered to be at risk within each 3-digit SIC. The expert panel's report, entitled "Summary of OSHA Expert Panel Meeting on Ergonomics" (Kearney/Centaur 1992), concluded that musculoskeletal risk factors are found in all industry sectors and in nearly all 3-digit industries (Ex. 26-1594).

The survey instrument was designed and developed by a survey statistician based on the expert panel's comments and recommendations, as well as on the results of a literature review conducted by Kearney/Centaur. The review of the survey design and questionnaire was a Departmental effort. Comments were solicited from the Directorates of Health Standards Programs, Safety Standards Programs, and Technical Support, the OSHA Office of Statistics, and the offices of the Assistant Secretary for Policy, the Assistant Secretary for Administration and Management, and the Solicitor of Labor. Survey instructions and design elements were reviewed by OSHA's contractor survey experts to ensure that logic checks were adequately incorporated in the design. Thereafter, the survey design was reviewed and approved by the Office of Information and Regulatory Affairs within the Office of Management and Budget.

Establishments to be surveyed were selected based on a statistical sample of all establishments in the surveyed industry sectors. For each SIC, establishments were selected from four size categories:

(a) 1-19 employees

(b) 20-99 employees

(c) 100-249 employees

(d) 250 or more employees.

Use of these size categories permitted the results of the survey to be analyzed by establishment type and employment size.

Survey Cells

Estimation cells made up of groups of industries were created by grouping together certain industries that exhibited "ergonomic commonality" (i.e., that had roughly similar levels of musculoskeletal risks).

• the ergonomic hazard "score" for each industry group, as assigned by the panel of ergonomists and health scientists assembled by OSHA;

• published Bureau of Labor Statistics (BLS) repeated trauma illness rates; and

• similarities among the types of industries, such as common occupations and processes, that facilitated or allowed for aggregation for estimation purposes.

Industries at the three-digit SIC level that received high panel scores or were reported by BLS to have high repeated trauma illness rates relative to their two-digit industry group were grouped into separate estimation cells to ensure the assignment of larger sample sizes into these industries with higher perceived or reported hazards. Three-digit SIC groupings within a given estimation cell typically shared common industry characteristics, such as occupations or processes.

For example, estimation cell #04, which consisted of SICs 201 and 203, was designed according to the above criteria. SICs 201 and 203 both had higher panel scores and higher BLS repeated trauma illness rates than was the case for the other 3-digit SICs within SIC 20. Occupations common to both SICs 201 and 203 included hand packers and packagers; drivers; forklift operators; manual hand material handlers; machine or conveyor feeders or offbearers; and production inspectors, sorters and testers. Common processes included loading or offloading; shipping, receiving or material handling; warehouse operations; and packing and crating.

Similarly, estimation Cell 15, which includes SICs 34 and 35, is a cell which was created based upon similar industry characteristics. Common occupations across both SICs include hand assemblers and fabricators, grinders and polishers; hand packers and packagers; machine or conveyor feeders or offbearers; and welders and flamecutters.

A final example is the case of Lumber and Wood Products (SIC 24) and Furniture and Fixtures (SIC 25) industries, grouped together in Survey Cell 09. However, certain 3-digit SICS within the Lumber and Wood Products and Furniture and Fixtures industries, such as Logging (SIC 241), were separated out from the remainder of the 3-digit SICs in these industries to form their own estimation cell (Cell 08) because their level of perceived musculoskeletal risk was higher than that for the other industries.

This approach guaranteed that those industries with the greatest risks (and thus potentially most impacted), were sampled most extensively. The Agency feels confident that the data gathered by the survey provide the maximum level of industry detail achievable with statistical accuracy and within the Agency's resource constraints. The survey estimation cells are shown in Exhibit 1.

In preparation for the survey, OSHA sent a letter to each potential survey respondent two weeks in advance of the initial phone contact. The letter described the nature of the project and the topics to be covered by the survey. Each participant received a list of occupations and processes that the interviewer would ask about (i.e., would "prompt" for) in their industry. When more than one establishment belonging to the same company had been selected to participate in the survey, a complete copy of the survey was also included in the letter. In addition, if a respondent requested a copy of the survey, one was sent. OSHA believes that this advance preparation allowed respondents to respond to the survey questions accurately and completely. Overall, the survey achieved a 58.4 percent response rate (the number of completed interviews/the number of viable cases contacted), with only minimal variation by size category: 57.4% among employers with 1-19 employees and 57.9% among those with more than 250 employees. The completion rate (45.6%) among the larger group of active attempts had more variance by size group, but this was due in part to the relatively large number of self-employed respondents in the 1-19 employee group (who do not fall within OSHA's jurisdiction, and therefore were not surveyed). There was no consistent variation in the rate of completions by size group.

Source: Office of Regulatory Analysis, OSHA.

The field survey was conducted by The Washington Consulting Group, one of OSHA's former contractors, using the Computer-Assisted Telephone Interviewing (CATI) technique. For each establishment, trained interviewers requested data on employment, musculoskeletal risk factors, control measures, training, medical management, and the effectiveness of their ergonomics program and interventions. Respondents were also asked to verify that certain workplace risk factors and processes were present in establishments in their industry, as well as to provide information on occupations, risk factors, and components of the establishment's ergonomics program. The technical details of the survey are provided in Washington Consulting Group's Documentation of OSHA Ergonomics Survey (WCG March 1994) (Ex. 26-1595).

Weighting and Benchmarking Survey Data

As described in WCG's survey report, Washington Consulting Group originally created a stratified sampling frame of establishments by size class and sample cell, based on the Dun and Bradstreet marketing data base. Accordingly, each establishment "pulled" from this sampling frame was assigned a weight for its size class and sample cell. After these establishments were surveyed, these weights were applied to create an estimated universe based on the Dun and Bradstreet data. However, while the Dun and Bradstreet data base is invaluable for creating a sampling frame, OSHA considers data from public sources generally more accurate for capturing the truest profile of industry. Therefore, those data were then "benchmarked" against Bureau of Census data, the weighted survey profile essentially applied to the Census universe.