Description

OCC2010 is a harmonized occupation coding scheme that recodes information contained in the variable OCC from prior and subsequent classification schemes to the Census Bureau 2010 occupation codes. OCC2010 was developed to enhance the comparability of occupational data by providing a consistent set of occupational codes for IPUMS USA from 1950 forward. Similar variables are offered for the 1950 (OCC1950) and 1990 (OCC1990) classification codes. Original, un-recoded occupation categories are available in the OCC variable.

Beginning in 2012 some 2010 Census occupation codes are collapsed in the data for categories that contained less than 10,000 people in the ACS sample. These categories are not included in the ACS data and so OCC2010 is harmonized to the collapsed codes. This crosswalk shows the detailed 2010 codes that get combined in 2012.

Modal Assignment
Mapping the changing Census occupation classification codes to the 2010 Census codes is largely done using modal assignment. In this technique, crosswalks from the Census Bureau are used to track when occupations break into more specific categories in the adjacent coding scheme or collapse into a more general occupation. Categories from the base occupation coding scheme are mapped to the target occupation coding scheme (in this case, the 2010 Census codes) following a plurality of records, as defined by the Census crosswalks. Modal assignment is also used when mapping new Census Bureau coding schemes back to the 2010 coding scheme; see Williams and Flood (2020) for a detailed description of backward modal assignment.

For example, the 2002 Census occupation code 0620 (Human Resources, Training, and Labor Relations Specialists) splits into three 2010 Census occupation codes 0630 (Human Resources Workers), 0640 (Compensation, Benefits, and Job Analysis Specialists), and 0650 (Training and Development Specialists). According to the Census Bureau crosswalk, 73% of the 2002 occupation category Human Resources, Training, and Labor Relations Specialists would be classified as Human Resource workers in the 2010 Census occupation coding scheme. Thus, IPUMS recodes the 2002 code 0620 to the 2010 code 0630.

Forced Recoding
In some instances, modal assignment results in non-sensical recodings. Non-sensical results from modal assignment when specific categories get collapsed into more general categories and, in a subsequent Census occupation classification, this general category is again broken up into many more specific categories. Non-sensical results can also occur as occupations change or become obsolete over time. In addition, these types of outcomes occur more frequently as more occupation classifications need to be bridged to map to the target 2010 Census codes (e.g. modal assignment results in more frequent questionable outcomes between the 1970 Census occupation codes and the 2010 occupation codes than between the 2000 occupation codes and the 2010 occupation codes).

An example of a forced recoding in OCC2010 is the 1980 Census category "Telegraphers." Between 1980 and 1990, Telegraphers are grouped together with other categories into a general category "Communications equipment operators, n.e.c." This general category is then broken into multiple more detailed categories between the 1990 and 2000 Census coding schemes; modal assignment across this change matches 1980 "Telegraphers" with 2000 "Switchboard Operators, Including Answering Service." This Switchboard Operators category remains unchanged across the 2000-2010 occupation codes change. However, the occupation of telegrapher is largely obsolete by 2010 and is not especially analogous with switchboard operator. Thus, IPUMS forces 1980 Telegraphers to be recoded to the 2010 occupation category " Communications Equipment Operators, All Other."

Another example of forced recoding is the 1970 category "Floor layers, except tile setters." This category is collapsed into a general category in the 1980 occupation coding scheme, "Construction trades, n.e.c." This category remains unchanged in the 1990 occupation categories, but in the 2000 Census occupation coding scheme, "Construction trades, n.e.c." is split into 18 more detailed categories. Modal assignment across this split goes to "Highway maintenance workers" with 20.28% of "Construction trades, n.e.c." cases landing in this new category. However, floor laying and highway maintenance have little to do with one another and modal assignment in this case is not desirable. Instead, IPUMS forces this recode to another of the 18 new 2000 Census codes, "Carpet, floor, and tile installers and finishers." This category remains unchanged in the transition from 2000 Census codes to 2010 Census codes. Even though this 2010 recode is not perfect (tile installers are included in the 2010 category, but excluded in the 1970 category), the forced recode provides a more reasonable alignment of occupation categories than modal assignment in this case.

Crosswalks
The IPUMS crosswalks showing the mapping of each Census occupation classification scheme to the 2010 Census occupation codes are below. Whether or not a recoding was forced to something other than the modal assignment outcome are indicated in the farthest right column. Note that the 2000 Census codes shown in the crosswalk are identical to the 2002 Census codes, but for a trailing zero in the 2002 codes.

• 1950 to 2010 Census occupation code mapping

• 1960 to 2010 Census occupation code mapping

• 1970 to 2010 Census occupation code mapping

• 1980 to 2010 Census occupation code mapping

• 1990 to 2010 Census occupation code mapping

• 2000 to 2010 Census occupation code mapping(2000 Census and 2000-2002 ACS/PRCS samples)

• Note that the 2002 Census occupation codes used in the 2003-2009 ACS/PRCS samples are identical to the 2000 Census occupation codes except for a trailing zero in all 2002 occupation code values

• OCC and OCC2010 are identical ACS/PRCS samples from 2010-2017

• 2018 to 2010 Census occupation code mapping (ACS/PRCS samples from 2018 onward)

In the 2018 Census occupation categories, several occupations that were combined into more general categories are once again unique categories. These categories, which have the same codes and occupation titles in the 2010 and 2018 Census occupation categories, are

• 4160 - Food preparation and serving related workers, all other

• 6540 - Solar photovoltaic installers

• 8000 - Grinding, lapping, polishing, and buffing machine tool setters, operators, and tenders, metal and plastic

These 2018 codes are mapped back to their collapsed 2010/2012 counterparts in OCC2010.

Major Occupation Groups
For users who wish to aggregate occupation to broader categories, the 2010 scheme is generally organized by the following groups:

Management in Business, Science, and Arts = 10-430
Business Operations Specialists = 500-730
Financial Specialists = 800-950
Computer and Mathematical = 1000-1240
Architecture and Engineering = 1300-1540
Technicians = 1550-1560
Life, Physical, and Social Science = 1600-1980
Community and Social Services = 2000-2060
Legal = 2100-2150
Education, Training, and Library = 2200-2550
Arts, Design, Entertainment, Sports, and Media = 2600-2920
Healthcare Practitioners and Technicians = 3000-3540
Healthcare Support = 3600-3650
Protective Service = 3700-3950
Food Preparation and Serving = 4000-4150
Building and Grounds Cleaning and Maintenance = 4200-4250
Personal Care and Service = 4300-4650
Sales and Related = 4700-4965
Office and Administrative Support = 5000-5940
Farming, Fisheries, and Forestry = 6005-6130
Construction = 6200-6765
Extraction = 6800-6940
Installation, Maintenance, and Repair = 7000-7630
Production = 7700-8965
Transportation and Material Moving = 9000-9750
Military = 9800-9830
No Occupation = 9920