The median divides the earnings distribution into two equal parts: one- half of the cases falling below the median and one-half above the median. Median earnings is restricted to individuals 16 years old and over with earnings and is computed on the basis of a standard distribution. (See the "Standard Distributions" section under "Derived Measures.") Median earnings figures are calculated using linear interpolation. (For more information on medians and interpolation, see "Derived Measures.")

Industry data describe the kind of business conducted by a person's employing organization. Industry data were derived from answers to questions 42 through 44 in the 2021 American Community Survey. Question 42 asks: "For whom did this person work?" Question 43 asks: "What kind of business or industry was this?" Question 44 provides four checkboxes from which respondents are to select one to indicate whether the business was primarily manufacturing, wholesale trade, retail trade, or other (agriculture, construction, service, government, etc.).

These questions were asked of all people 15 years old and over who had worked in the past 5 years. 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.

Coding Procedures - Written responses to the industry questions are coded using the industry classification system developed for Census 2000 and modified in 2002, 2007, 2012 and again in 2017. This system consists of 269 categories for employed people, including military, classified into 20 sectors, plus an additional Census code for the unemployed, with no work experience in the last 5 years or earlier or never worked for a total of 270 Census industry codes. The modified 2017 Census industry classification was developed from the 2017 North American Industry Classification System (NAICS) (http://www.census.gov/eos/www/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 ACS 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 that the NAICS provides.

Respondents provided the data for the tabulations by writing on the questionnaires descriptions of their kind of business or industry. These write-ins are converted to a code category through automated coding. Cases not autocoded on both industry and occupation are sent to the clerical staff in the National Processing Center in Jeffersonville, Indiana who assign codes by comparing these descriptions to entries in the most current Alphabetical Index of Industries and Occupations (https://www.census.gov/topics/employment/industryoccupation/guidance/indexes.html).

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.

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 industry include janitors, security guards, and secretaries.

Editing Procedures - 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 industry are checked for consistency with the occupation and class of worker data provided for that respondent. Occasionally respondents supply industry descriptions that are not sufficiently specific for precise classification, or they do not report on these questions at all. Certain types of incomplete entries are corrected using the Alphabetical Index of Industries and Occupations. If one or more of the three codes (industry, occupation, or class of worker) is blank after the edit, a code is assigned from a donor respondent who is a "similar" person based on questions such as age, sex, educational attainment, income, employment status, and weeks worked. If all of the labor force and income data are blank, all of these economic questions are assigned from a "similar" person who had provided all the necessary data.

These questions describe the industrial composition of the American labor force. Data are used to formulate policy and programs for employment, career development and training, and to measure compliance with antidiscrimination policies. Companies use these data to decide where to locate new plants, stores, or offices.

Question/Concept History - Industry data have been collected during decennial censuses intermittently since 1820 and on a continuous basis since 1910. Starting with the 2010 Census, industry data will no longer be collected during the decennial census. Long form data collection has transitioned to the ACS. The ACS began collecting data on industry in 1996. The questions on industry were designed to be consistent with the 1990 Census questions on industry. In the 1990 Census and starting with the 1999 ACS, a check box was added to the employer name questionnaire item that was 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. Prior to 1999, the 1996-1998 ACS class of worker question had an additional response category for "Active duty U.S. Armed Forces member." Other than this exception, ACS questions on industry have remained consistent between 1996 and 2021.

Limitation of the Data - Beginning in 2006, the population in group quarters (GQ) was included in the ACS. Some types of GQ populations have industry distributions that are different from the household population. The inclusion of the GQ population could therefore have a noticeable impact on the industry distribution in some geographic areas with a substantial GQ population.

Data on occupation, industry, and class of worker are collected for the respondent's current primary job or the most recent job for those who are not employed but have worked in the last 5 years. Other labor force questions, such as questions on earnings or work hours, may have different reference periods and may not limit the response to the primary job. Although the prevalence of multiple jobs is low, data on some labor force items may not exactly correspond to the reported occupation, industry, or class of worker of a respondent.

Comparability - Comparability of industry data was affected by a number of factors, primarily the system used to classify the questionnaire responses. Changes in the industry classification system limit comparability of the data from one year to another. These changes are needed to recognize the "birth" of new industries, the "death" of others, the growth and decline in existing industries, 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, respondent terminology, and refinement of category composition made these movements necessary.

ACS data from 1996 to 1999 used the same industry classification systems used for the 1990 Census; therefore, the data are comparable. Since 1990, the industry classification has had major revisions to reflect the shift from the Standard Industrial Classification (SIC) to the North American Industry Classification System (NAICS). These changes were reflected in the Census 2000 industry codes. For more information on industry comparability across classification systems, please see technical paper #65: The Relationship Between the 1990 Census and Census 2000 Industry and Occupation Classification Systems
(http://www.census.gov/people/io/files/techpaper2000.pdf). The 2000-2002 ACS data used the same industry and occupation classification systems used for the Census 2000; 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 being added to the list of codes, the Census Bureau needed to have more flexibility in adding codes. Consequently, in 2002, industry census codes were expanded from three-digit codes to four-digit codes. The changes to these code classifications mean that the ACS data from 2003-2007 are not completely comparable to the data from earlier surveys. In 2007, 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). The ACS followed the 2007 code list through 2012, making the ACS 2007-2012 industry codes comparable. NAICS was updated again in 2012. The changes were used to create the 2012 Census industry code list, which was first applied to the 2013 ACS. The revision included 9 new codes (3095, 3365, 3875, 3895, 4195, 4265, 4795, 5275, 5295), 9 deletions (3090, 3360, 3870, 3890, 4190, 4260, 4790, 5270, 5290) and 19 title changes. These changes make the 2012 Census industry codes only partially comparable with previous years. The ACS followed the 2012 code list through 2017. In 2017, the NAICS was updated again. The 2017 NAICS updated were used to create the 2017 Census industry code list, which was first applied to the 2021 ACS, The revision included 19 new codes ('1691', '3291', '4971', '4972', '5381', '5391', '5393', '6991', '6992', '7071', '7072', '7181', '8191', '8192', '8561', '8562', '8563', '8564', '8891'), 17 deletions ('1680', '1690', '3190', '3290', '4970', '5380', '5590', '5591', '5592', '6990', '7070', '7170', '7180', '8190', '8560', '8880', '8890') and 18 title changes. These changes make the 2017 Census industry codes only partially comparable with previous years.

For more information, see the 2017 Census Industry Code List within the 2021 ACS Code List. Go to (http://www.census.gov) and enter "“ACS Code Lists, Definitions, and Accuracy" in the search box.

See also Occupation and Class of Worker.

All people 16 years old and over who usually worked 35 hours or more per week for 50 to 52 weeks in the past 12 months.