Lewis Mumford Center Comparabillity Report page 4

The 1998 SOC contains 822 detailed occupations, aggregated into 452 broad occupations. These broad occupations are grouped into 98 minor groups that are grouped into the 23 major groups. For users wanting less detail in data tabulations, the Standard Occupational Classification Revision Policy Committee (SOCRPC) suggests combining the 23 major groups into 11 "intermediate-level aggregations," or even 6 "high-level aggregations" (SOC Federal Register Notice, 1999). These three levels of aggregation for the 1998 SOC are presented in Table 1. Note that codes 11-0000 through 29-0000 represent the occupations that Census 2000 has treated as managerial/professional.

In contrast, the 1980 SOC included 664 unit groups (comparable to detailed occupations in the 1998 SOC), 223 minor groups (comparable to broad occupations in the 1998 SOC), 60 major groups (comparable to minor groups in the 1998 SOC), and 22 divisions (comparable to major groups in the 1998 SOC). The structure of the 1980 SOC is presented in Table 2.

Reconfiguration of the 1980 Standard Occupational Classification

Although historical comparability was recognized as important for analyzing long-term trends in employment and other characteristics of workers, such comparability was not the primary consideration in the development of the 1998 SOC. Nevertheless many analysts will want to make comparisons across years, and they need to know how to link the 1998 SOC "Management, Professional, and Related Occupations" (SOC codes 11-0000 to 29-0000) shown in Table 1 and the 1980 SOC "Managerial and Professional Specialty Occupations" (SOC codes 1100-1499 to 3200-3400) shown in Table 2.