By incorporating the Standard Occupational Classification (SOC) into case service documentation with the start of the 2007 fiscal year (FY) on October 1, 2006, the Rehabilitation Service Administration's (RSA) vocational rehabilitation (VR) program joined other federal agencies in using a standardized approach to classifying occupational information (Levine & Salmon, 1999; RSA, 2006). As a result, the SOC replaces the outdated Department of Labor's Dictionary of Occupational Titles (DOT) as the formal system to classify the type of occupation achieved by VR consumers (Mariani, 1999; U.S. Department of Labor, 1991). Since the concept of employment is central to many rehabilitation practitioners and people with disabilities (Fraser, Vandergoot, Thomas, & Wagner, 2004; Martz & Xu, 2008), it is important to explore and describe this baseline occupational information for consumers of the VR program and the general United States population. Preceding this analysis is a brief history on classifying occupations followed by an overview of the SOC.
The first occupational classification system in the United States was developed with the 1850 Census of Population (Levine & Salmon, 1999; Levine, Salmon, & Weinberg, 1999). The government surveyed the population for the "profession, occupation, or trade of each person over 15 years of age" (U.S. Census Bureau, 2009a, Schedule no. 1 section). From this one question to 23 million residents across 30 states, 322 occupations were identified including cotton-gin maker, drover, lath maker, rag collector, and stevedore (Levine et al., U.S. Census Bureau, 2009c). Eventually, the census surveys included not just one, but multiple questions regarding the nature of work performed (U.S. Census Bureau, 2009b). The U.S. government has since been collecting occupational data on its residents for almost 160 years.
Following the rapid expansion of U.S. manufacturing in the early decades of the 20th century, a Standard Industrial Classification (SIC) system was created to systematically organize expanding industries (Levine et al.). An important aspect of the SIC was that it conformed to the existing industrial structure of the United States (Pearce, 2009). For example, industries were classified by a four-digit code and represented agriculture, communication, construction, electric, finance, fisheries, forestry, gas, insurance, manufacturing, mining, real estate, retail, sanitary services, services, transportation, and wholesale trade. The most recent version of the SIC was hierarchically sectioned into divisions (e.g., Division I: Services), major groups (e.g., Major Group 83: Social Services), and industrial groups (e.g., Industrial Group 8331 : Job Training and Vocational Rehabilitation Services) (U.S. Department of Labor, 2009). The SIC was used for many decades until it began to show signs of stress as the nation shifted to a service-oriented economy with the introduction of new industries such as information technology, healthcare, and high-tech manufacturing (Levine et al., 1999). In addition, the 1994 North American Free Trade Agreement (NAFTA) opened up trade with Canada and Mexico, signaling the need for an international industrial classification system.
In 1997, the Office of Management and Budget (OMB) replaced the ailing SIC with the North American Industry Classification System (NAICS) (Murphy, 1998). The NAICS is hierarchically organized by groups of industries with similar production processes and can be individualized by participating countries to meet their own needs (Levine et al.). NAICS' six-digit classification codes allows for greater flexibility in structure than the SIC (Murphy). The highest level of aggregation represents industrial sectors (e.g., information), followed by subsectors (e.g., broadcasting and telecommunications), industry groups (e.g., radio and television), international industries (e. …