Industry, Occupation, and Class of Worker
The data on industry, occupation, and class of worker were derived from answers to Questions 35 through 40. These questions were asked of all people 15 years old and over who had worked in the past 5 years. Information on industry relates to the kind of business conducted by a person's employing organization; occupation describes the kind of work the person does on the job; and class of worker categorizes people according to the type of ownership of the employing organization. For employed people, the data refer to the person's job during the previous week. For those who worked two or more jobs, the data refer to the job where the person worked the greatest number of hours. For unemployed people and people who are not currently employed but report having a job within the last five years, the data refer to their last job. Occupation statistics are compiled from data that are coded based on the detailed classification systems developed for Census 2000 and modified in 2002. The industry classification system was developed for Census 2000 and modified in 2002 and again in 2006. The class of worker statistics are derived from data coded the same as in previous censuses.
Respondents provided the data for the tabulations by writing on the questionnaires descriptions of their kind of business or industry and the kind of work or occupation they are doing. A clerical staff in the National Processing Center in Jeffersonville, Indiana, converted the written questionnaire descriptions to codes by comparing these descriptions to entries in the Alphabetical Index of Industries and Occupations http://www.census.gov/hhes/www/ioindex/ioindex02/view02.html
The data on industry were derived from answers to Questions 36 through 38. Written responses to the industry questions are coded using the industry classification system developed for Census 2000 and modified in 2002 and again in 2006. This system consists of 269 categories for employed people, including military, classified into 20 sectors. The modified 2006 census industry classification was developed from the 2006 North American Industry Classification System (NAICS) published by the Executive Office of the President, Office of Management and Budget. The NAICS was developed to increase comparability in industry definitions between the United States, Mexico, and Canada. It provides industry classifications that group establishments into industries based on the activities in which they are primarily engaged. The NAICS was created for establishment designations and provides detail about the smallest operating establishment, while the American Community Survey data are collected from households and differ in detail and nature from those obtained from establishment surveys. Because of potential disclosure issues, the census industry classification system, while defined in NAICS terms, cannot reflect the full detail for all categories. The industry category, "Public administration," is limited to regular government functions such as legislative, judicial, administrative, and regulatory activities. Other government organizations such as public schools, public hospitals, and bus lines are classified by industry according to the activity in which they are engaged.
The data on occupation were derived from answers to Questions 39 and 40. Written responses to the occupation questions are coded using the occupational classification system developed for the 2000 census and modified in 2002. This system consists of 509 specific occupational categories, for employed people, including military, arranged into 23 major occupational groups. This classification was developed based on the Standard Occupational Classification (SOC) Manual: 2000 , published by the Executive Office of the President, Office of Management and Budget. Some occupation groups are related closely to certain industries. Operators of transportation equipment, farm operators and workers, and healthcare providers account for major portions of their respective industries of transportation, agriculture, and health care. However, the industry categories include people in other occupations. For example, people employed in agriculture include truck drivers and bookkeepers; people employed in the transportation industry include mechanics, freight handlers, and payroll clerks; and people employed in the health care profession include janitors, security guards, and secretaries.
The data on class of worker were derived from answers to Question 35. The information on class of worker refers to the same job as a respondent's industry and occupation and categorizes people according to the type of ownership of the employing organization. The class of worker categories are defined as follows:
Private wage and salary workers
Includes people who worked for wages, salary, commission, tips, pay-in-kind, or piece rates for a private for-profit employer or a private not-for-profit, tax-exempt or charitable organization. Self-employed people whose business was incorporated are included with private wage and salary workers because they are paid employees of their own companies.
ACS tabulations present data separately for these subcategories: "Private for-profit wage and salary workers," "Private not-for-profit wage and salary workers," "Self-employed in own incorporated business workers," and "Own not incorporated business workers."
Includes people who were employees of any local, state, or federal governmental unit, regardless of the activity of the particular agency. For ACS tabulations, the data are presented separately for the three levels of government.
Employees of foreign governments, the United Nations, or other formal international organizations controlled by governments were classified as "federal government workers."
The class of worker government categories includes all government workers, though government workers may work in different industries. For example, people who work in a public elementary or secondary school are coded as local government class of workers.
Self-employed in own not incorporated business workers
Includes people who worked for profit or fees in their own unincorporated business, profession, or trade, or who operated a farm.
Includes people who worked without pay in a business or on a farm operated by a relative.
Following the coding operation, a computer edit and allocation process excludes all responses that should not be included in the universe, and evaluates the consistency of the remaining responses. The codes for the three questions (industry, occupation, and class of worker) are then checked to ensure they are valid and consistent with the other codes returned for that respondent. Occasionally respondents supplied industry, occupation, or class of worker descriptions that were not sufficiently specific for precise classification, or they did not report on these questions at all. Certain types of incomplete entries were corrected using the Alphabetical Index of Industries and Occupations .
If one or more of the three codes was blank after the edit, a code was assigned from a donor respondent who was a "similar" person based on questions such as age, sex, education, and weeks worked. If all of the labor force and income data were blank, all of these economic questions were assigned from a "similar" person who had provided all the necessary data.
Comparability of industry and occupation data was affected by a number of factors, primarily the systems used to classify the questionnaire responses. In both the industry and occupation classification systems, changes in the individual categories limit comparability of the data from one year to another. These changes are needed to recognize the "birth" of new industries and occupations, the "death" of others, the growth and decline in existing industries and occupations, and the desire of analysts and other users for more detail in the presentation of the data. Probably the greatest cause of noncomparability is the movement of a segment from one category to another. Changes in the nature of jobs and respondent terminology and refinement of category composition made these movements necessary.
Data for the 1998 and 1999 ACS used the same industry and occupation classification systems used for the 1990 census; therefore, the data are comparable. Since 1990, both the industry and occupation classifications have had major revisions to reflect the shift from the Standard Industrial Classification (SIC) to the North American Industry Classification System (NAICS) and changes within the Standard Occupational Classification (SOC). These changes were reflected in the Census 2000 industry and occupation codes. The 2000-2002 ACS data used the same industry and occupation classification systems used for the 2000 census, therefore, the data are comparable. In 2002, NAICS underwent another change and the industry codes were changed accordingly. Because of the possibility of new industries and occupations being added to the list of codes, the Census Bureau needed to have more flexibility in adding codes. Consequently, in 2002, both industry and occupation census codes were expanded from three-digit codes to four-digit codes. The changes to these code classifications mean that the ACS data from 2003-2006 are not completely comparable to the data from earlier surveys. In 2006, NAICS was updated again. This resulted in a minor change in the industry data that will cause it to not be completely comparable to previous years. The changes were concentrated in the Information Sector where one census code was added (6672) and two were deleted (6675, 6692).
Beginning in 2006, the population in group quarters (GQ) was included in the ACS. Some types of GQ populations have industry, occupation, and class of worker distributions that are very different from the household population. The inclusion of the GQ population could therefore have a noticeable impact on the industry, occupation, and class of worker distribution. This is particularly true for areas with a substantial GQ population.
The American Community Survey questions on industry, occupation, and class of worker were changed to match the Census 2000 questions, beginning with the 1999 ACS questionnaire. The 1996-1998 ACS "Class of Worker" question had an additional response category for "Active duty U.S. Armed Forces member." People who marked this category were tabulated as federal government workers. To capture these respondents, a check box was added to Industry question 36 in 1999. This check box is to be marked by anyone "now on active duty in the Armed Forces...." This information is used by the industry and occupation coders to assist in assigning proper industry codes for active duty military.