The Relationship Between The 1990 Census and ... - Census Bureau

entertainment, and recreation,” “Health care and social assistance,” “Professional, scientific, and
technical services,” and “Other services.”
REVISIONS TO THE OCCUPATIONAL CLASSIFICATION
The Census 2000 occupational classification system was based on the structure of the 2000 SOC. The
2000 SOC replaced the 1980 SOC to reflect the dramatic changes in the nation’s labor force over the
previous two decades. In 1994, the OMB established the Standard Occupational Classification Revision
Policy Committee (SOCRPC), and charged it with identifying the major statistical uses of occupational
classifications, and creating a classification system that reflects the current occupational structure in the
United States. More than 15 federal government agencies participated in this process.
Like the 1980 SOC, the new classification covers all occupations in which work is performed for pay or
profit, including work performed in family-operated enterprises by family members who are not directly
compensated. Occupations are classified based on work performed and on required skills, education,
training, and credentials 3 . The SOCRPC decided, however, to rearrange the entire structure of the
classification rather than to start with the old SOC and simply try to make improvements. For the new
SOC, the SOCRPC chose to arrange the world of work into “job families,” in which people who work
together are classified together. The end result was truly a major change from the past.
The principle behind the concept of “job families” in the new SOC was to place people who worked
together in the same group, regardless of their skill levels. Based on this concept, many occupations that
used to be called professionals and technicians now appear together in the same group. For example,
physicians, registered nurses, and medical laboratory technicians are all in the same SOC and census
major group in 2000. This arrangement differs from that of the old SOC, where these levels of
occupations were separate.
On the other hand, while first-line supervisors are found in the same major groups as the workers they
supervise, higher management levels are not. Managers are in their own major group. For example, farm
managers and self-employed farmers are now under the group for “Managerial occupations” instead of the
group for “Farming, fishing, and forestry occupations,” where they were classified in the past.
The resulting 2000 SOC arranged occupations into 23 major groups, compared to 22 divisions used by the
1980 SOC, and 821 detailed categories. The Census Bureau then aggregated these detailed SOC
categories into 509 detailed census categories within the same 23-major group framework of the SOC.
In the change from the 1990 Census to the Census 2000 occupational classification, there were many
detailed categories and parts of detailed categories that shifted between the 1990 and 2000 published data.
The people in these categories, in effect, “moved” from one category to another as a result of
classification change rather than due to a real change in the workforce. The adjustments made to the 1990
data in this paper account for these movements of people in these categories, and thereby make the 1990
data comparable to the 2000 data.
The following are some of the major differences between the 1980 and 2000 SOC, which in turn are
reflected as major differences between the 1990 and 2000 census data:
3 See Bernan Associates: Standard Occupational Classification Manual: 2000; October 2000.
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