Description

OCC1990 is a modified version of the 1990 Census Bureau occupational classification scheme. OCC1990 provides researchers with a consistent classification of occupations using the 1990 coding scheme as its starting point. It spans the period from 1950 forward. Researchers who want consistent occupations prior to 1950 should consult OCC1950.

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While the 1990 Census occupation classification system is the basis for OCC1990, we combine several categories to improve the variable's comparability over time. Users are encouraged to review the BLS working paper that describes the variable and how available categories map to 1960-2000 Census occupation codes.

Creation of OCC1990
OCC1990 was created using a series of technical papers published by the Census Bureau shortly after each census was administered. These papers provide detailed analyses of how the occupational coding scheme for each census year differed from the scheme used during the previous census year. These occupational "crosswalks" are based on samples of cases that are "double coded" into the occupational schemes of the current and previous census year. The original Census Bureau crosswalks are available via links in "Occupation and Industry Variables" of the IPUMS documentation.

Using the information from the occupational crosswalks, we traced the proportion of each occupation as it broke out into more specific occupations or as it was combined with others into a more general occupation. To take one example from the technical paper produced after the 2000 census: of persons coded as "Gaming managers" in 2000 (2000 code 33), the Census Bureau determined that 35% would have been coded as "Managers, service organizations" in 1990 (1990 code 21), while 65% would have been coded as "Managers, food serving and lodging establishments" (1990 code 17). In OCC1990, we assign original 2000 OCC values of 33 to 17. We generated the same information for every occupational code in every census year from 1950-2000.

Researchers at the Bureau of Labor Statistics (BLS) then used the resulting tables to create aggregated occupational categories that were more useful for long-term analyses; these are the categories that are used in the IPUMS variable OCC1990. More specifics on their methods and a detailed comparison of OCC1950 and OCC1990 can be found in the resulting BLS working paper.

The IPUMS codes differ from those outlined in the BLS working paper in two instances.

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While OCC1990 has fewer occupational categories than the original 1990 occupational scheme, users may want to further aggregate categories into the broad occupational categories implicit in the 1990 scheme:

• Managerial and Professional (000-200);

• Technical, Sales, and Administrative (201-400);

• Service (401-470);

• Farming, Forestry, and Fishing (471-500);

• Precision Production, Craft, and Repairers (501-700);

• Operatives and Laborers (701-900);

• Non-occupational responses (900-999).

Universe Note: "New Workers" are persons seeking employment for the first time, who had not yet secured their first job.