November 27, 2018

U.S. Unauthorized Immigrant Total Dips to Lowest Level in a Decade

Methodology

The estimates presented in this report supersede all previously published Pew Research Center estimates. Although this report draws largely on U.S. Census Bureau data, our estimates will not generally agree exactly with those published by the Census Bureau because we include adjustments for survey omissions and corrections for various types of survey errors and anomalies.

Overview

The estimates for the U.S. unauthorized immigrant population presented in this report are based on a residual estimation methodology that compares a demographic estimate of the number of immigrants residing legally in the country with the total number of immigrants as measured by either the American Community Survey or the March Supplement to the Current Population Survey. The difference is assumed to be the number of unauthorized immigrants in the survey, a number that later is adjusted for omissions from the survey (see below). The basic estimate is:

Unauthorized
Immigrants
(U)
= Survey, Total
Foreign Born
(F)
Estimated Lawful
Immigrant Population
(L)

The lawful resident immigrant population is estimated by applying demographic methods to counts of lawful admissions covering the period since 1980 obtained from the Department of Homeland Security’s Office of Immigration Statistics and its predecessor at the Immigration and Naturalization Service, with projections to current years, when necessary. Initial estimates here are calculated separately for age-gender groups in six states (California, Florida, Illinois, New Jersey, New York and Texas) and the balance of the country; within these areas the estimates are further subdivided into immigrant populations from 35 countries or groups of countries by period of arrival in the United States. Variants of the residual method have been widely used and are generally accepted as the best current estimates (Baker, 2017; Warren and Warren, 2013). See also Passel and Cohn (2016b); Passel, Cohn and Gonzalez-Barrera, (2013), Passel and Cohn (2008), Passel (2007) and Passel et al. (2004) for more details.

The overall estimates for unauthorized immigrants build on these residuals by adjusting for survey omissions in these six states and the balance of the country, subdivided for Mexican immigrants and other groups of immigrants (balance of Latin America, South and East Asia, rest of world) depending on sample size and state.

Once the residual estimates have been produced, individual foreign-born respondents in the survey are assigned a specific status (one option being unauthorized immigrant) based on the individual’s demographic, social, economic, geographic and family characteristics in numbers that agree with the initial residual estimates for the estimated lawful immigrant and unauthorized immigrant populations in the survey. These status assignments are the basis for the characteristics reported here (including, for example, specific countries of birth, detailed state estimates, period of arrival and household-family relationships). A last step in the weighting-estimation process involves developing state-level estimates that take into account trends over time in the estimates.

Comparability with previous estimates

The estimates presented here for 1990-2016 are internally consistent and comparable across years and states. The 2005-16 estimates are based on the American Community Survey (ACS); those for 1995, 1998, 2000 and 2003 are based on the March Current Population Survey (CPS); and for 1990, on the 1990 census (produced by Warren and Warren, 2013). The estimates presented in this report supersede all previous published Pew Research Center estimates, especially estimates for the same dates using different data. For 2005-15, some previous estimates have been based on the CPS rather than the ACS; see, for example, a 2012 Pew Research Center report covering 1995-2011 using only CPS-based estimates and a 2017 publication with ACS-based estimates for 2005-15 and a preliminary estimate for 2016 based on the CPS. ACS-based estimates are superior to CPS-based estimates for reasons discussed below. Previous Center releases since September 2013 (Passel and Cohn, 2016a, 2016b; Passel et al., 2014; Passel, Cohn and Gonzalez-Barrera, 2013 and related graphics) include a mix of CPS-based and ACS-based estimates and also show CPS-based estimates for additional years: 1996-97, 1999, 2001-02 and 2004. These earlier estimates are consistent with estimates published here.

The estimates in this report and previous Center publications since 2013 are based on survey data consistent with the censuses of 1990, 2000 and 2010. For the 1995-2009 surveys, special weights were developed to align with both the preceding and subsequent censuses (see below). As such, population figures for these years are not identical to those published from the original surveys. Moreover, these new estimates of unauthorized immigrants differ from previous estimates published before 2013, even from earlier estimates based on the same surveys. Although differences at the national level are not generally very large, some state-level differences may be relatively greater. (See below for the bases for the revisions.)

The ACS has a much larger sample size than the CPS (see below). As such, state-level estimates of unauthorized immigrants and those for countries of birth are much more precise (i.e., have smaller margins of error) from the ACS than from the CPS. The larger sample sizes also permit more detailed analyses of the characteristics of unauthorized immigrants at the state level and for individual countries of birth.

Rounding of estimates

All estimates for unauthorized immigrant populations are presented as rounded numbers to avoid the appearance of unwarranted precision in the estimates. The rounding conventions for unauthorized immigrant estimates, dependent somewhat on data sources, are:

Greater than 10,000,000 Nearest 100,000
1,000,000-10,000,000 Nearest 50,000
250,000-1,000,000 Nearest 25,000
100,000-250,000 Nearest 10,000
ACS-based 5,000-100,000 Nearest 5,000
CPS-based 10,000-100,000 Nearest 5,000
ACS-based <5,000 Shown as <5,000
CPS-based <10,000 Shown as <10,000

Estimates for 1990 are based on the 1990 census and use ACS-based rounding conventions. These same conventions are used to round the 90% confidence intervals limits, presented as “Range (+ or -),” with one exception – limits that round to less than 5,000 are rounded to the nearest 1,000. For state- and national-level data on the total population or total foreign-born population, figures are rounded to the nearest 10,000.

Unrounded numbers are used for significance tests, for plotting charts and for computations of differences and percentages. Where differences are reported, they are computed from unrounded estimates and then rounded separately. Because each figure is rounded separately, the rounded estimates may not add to rounded totals. Similarly, percentages computed from rounded numbers may differ from the percentages shown in this report.

Status assignments: Lawful and unauthorized immigrants

Individual survey respondents are assigned a status as a lawful or unauthorized immigrant based on the individual’s demographic, social, economic and geographic characteristics so that the resulting number of immigrants in various categories agrees with the totals from the residual estimates. The assignment procedure employs a variety of methods, assumptions and data sources.

First, all immigrants entering the U.S. before 1980 are assumed to be lawful immigrants. Then, the ACS and CPS data are corrected for known overreporting of naturalized citizenship on the part of recently arrived immigrants (Passel et al., 1997). Specifically, immigrants who have been in the U.S. for less than six years are not eligible to naturalize unless they are married to a U.S. citizen, in which case they can naturalize after three years. Immigrants reporting as naturalized who fail to meet these requirements are moved into the noncitizen category. All remaining naturalized citizens from countries other than Mexico and those in Central America are assigned as lawful immigrants because reporting of citizenship for these groups has been found to be largely accurate in the aggregate (Passel et al., 1997). Mexican and Central American immigrants who report being naturalized U.S. citizens are treated the same as noncitizens in the status assignment process. This means that some may be assigned as unauthorized immigrants; the rest remain as naturalized citizens.

Persons entering the U.S. as refugees are identified on the basis of country of birth and year of immigration to align with known admissions of refugees and asylees (persons granted asylum). Then, individuals holding certain kinds of temporary visas are identified in the survey and each is assigned a specific lawful temporary migration status using information on country of birth, date of entry, occupation, education and certain family characteristics. The specific visa types identified and supporting variables are:

Diplomats and embassy employees (A visa)

Foreign students (F, M visa)

Visiting scholars (J visa)

Physicians (J visa)

Registered nurses (H-1A visas)

Intracompany transfers (L visas)

“High-tech” guest workers (H-1B visas)

International organizations (G visas)

Religious workers (R visas)

Exchange visitors (J visas)

Athletes, artists and entertainers (O, P visas)

Spouses and children within the various categories

Finally, immigrants are screened on the basis of occupations, participation in public programs and family relationships with U.S.-born individuals and lawful immigrants. Some individuals are assigned as lawful immigrants on the basis of these characteristics:

Refugees and naturalized citizens

Lawful temporary immigrants

Persons working for the government or the armed forces

Veterans or active-duty members of the armed forces, military Reserves or National Guard

Participants in government programs not open to unauthorized immigrants: Supplemental Security Income (SSI), Temporary Assistance for Needy Families (TANF), Medicare, Medicaid and food stamps (Supplemental Nutrition Assistance Program, or SNAP)

Persons entering the U.S. before 1980

Persons with certain occupations that require lawful status or government licensing (e.g., police officers and other law enforcement occupations, lawyers, health care professionals)

Children of citizens and lawful temporary migrants

Most immediate relatives of U.S. citizens, especially spouses

Other family members, especially those entering the U.S. before lawful residents

As result of these steps, the foreign-born population is divided between individuals with “definitely lawful” status (such as long-term residents, naturalized citizens, refugees and asylees, lawful temporary migrants and some lawful permanent residents) and a group of “potentially unauthorized” migrants. (See Passel, 2007 and Passel et al., 2004 for additional detail.)

Finally, virtually all Cubans entering the U.S. are lawful residents, even if they are not assigned refugee status, because they are treated differently from other arrivals based on the Cuban Adjustment Act of 1966. Status assignments in datasets for 2012 and earlier did not take the special status of Cubans into account and, as a result, assigned too many as unauthorized immigrants. To rectify the excess assignment of Cubans as unauthorized immigrants, a weighting adjustment was made in the CPS-based estimates for 1995-2003 and ACS-based estimates for 2005-12. In these adjustments, the weight previously assigned to unauthorized Cubans was reassigned to unauthorized immigrants from other parts of Latin America while keeping in place the overall unauthorized immigrant totals for states. These changes have been implemented in Pew Research Center publications since 2016.

The number of potentially unauthorized immigrants typically exceeds the estimated number of unauthorized immigrants from the residual estimates by 20%-35% nationally. So, to have a result consistent with the residual estimate of lawful and unauthorized immigrants, probabilistic methods are employed to assign lawful or unauthorized status to these potentially unauthorized individuals. The base probability for each assignment is the ratio of the residual estimate to the number of potentially unauthorized immigrants. These initial probabilities are first adjusted separately for parents living with their children and all others to ensure that an appropriate number of unauthorized immigrant children are selected and then by broad occupation categories.

After this last step in the probabilistic assignment process, there is a check to ensure that the statuses of family members are consistent; for example, all family members entering the country at the same time are assumed to have the same status. The resulting populations for unauthorized immigrants are compared with the residual estimates; if they disagree, the assignment probabilities are adjusted and the random assignments are repeated. The entire process requires several iterations to produce estimates that agree with the demographically derived population totals. At the end, the final estimates agree with the residual estimates for the six individual states noted earlier and for the balance of the country; for lawful and unauthorized immigrants in each area born in Mexico, Latin America, Asia and the rest of the world (subject to sample size considerations); and for children and for working-age men and women within each category. Finally, the survey weights for the foreign born are adjusted upward for survey omissions (undercount) so the tabulated figures agree with the adjusted analytic, demographic estimates of the total number of lawful immigrants and unauthorized migrants developed in the very first step.

Data sources and survey weights

The American Community Survey is an ongoing survey conducted by the U.S. Census Bureau that represents the population as of July 1 of each year. The survey collects detailed information on a broad range of topics, including country of birth, year of immigration and citizenship – the information required for the residual estimates. The ACS has a continuous collection design with monthly samples of almost 300,000 households. The initial sample has been slightly more than 3.5 million addresses each year since 2012. Initial nonresponse addresses are then subsampled for further interviews. The final sample for 2016 comprised more than 2.1 million addresses. The ACS began full-scale operation in 2005 covering only the household population; since 2006 it has covered the entire U.S. population. ACS data are released by the Census Bureau in September for the previous year. For this report, public-use samples of individual survey records from the ACS are tabulated to provide the data used in the estimation process. The public-use file is a representative 1% sample of the entire U.S. (including more than 3 million individual records for each year since 2008 – 3,156,000 in 2016). The public-use data employed in these estimates were obtained from the Integrated Public-Use Microdata Series, or IPUMS ((Ruggles et al., 2015).

The other survey data source used for residual estimates comes from March Supplements to the Current Population Survey. The CPS is a monthly survey currently of about 55,000 households conducted jointly by the U.S. Bureau of Labor Statistics and the Census Bureau. The March CPS Supplement has a greatly expanded questionnaire that collects detailed information on income sources, participation in a range of government programs and health insurance coverage. The March sample is also expanded over the regular monthly CPS by including additional households with children, Hispanics and specific race groups. Since 2001, the March Supplement sample has been expanded to about 80,000 households; before then, the expanded March Supplement sampled about 50,000 households. The CPS was redesigned in 1994 and, for the first time, included the information required for the residual estimates (i.e., country of birth, date of immigration and citizenship). Some limitations of the initial March Supplement of redesigned CPS, 1994 – especially the limited coding of country of birth – preclude its use in making these estimates, so the first CPS-based estimates of the unauthorized immigrant population are for March 1995. The CPS universe covers the civilian noninstitutional population. The March Supplement data from the CPS are released by the U.S. Census Bureau in September for the previous March.

Population figures from both the ACS and CPS are based on the Census Bureau’s official population estimates for the nation, states and smaller areas through a weighting process that ensures that the survey figures agree with prespecified national population totals by age, sex, race and Hispanic origin. At the subnational level, the two surveys differ in their target populations. The March CPS data agree with state-level totals by age, sex and race and are based on a process that imposes other conditions on weights for couples. The ACS weights use estimates for much smaller geographic areas that are summed to prespecified state totals.

The population estimates for the surveys are based on the latest available figures at the time the survey weights are estimated. This process produces the best estimates available at the time of the survey, but it does not guarantee that a time series produced across multiple surveys is consistent or accurate. Significant discontinuities can be introduced when the Census Bureau changes its population estimation methods, as it did several times early in the 2000s and in 2007 and 2008 (Passel and Cohn, 2010), or when the entire estimates series is recalibrated to take into account the results of a new census. The Census Bureau generally revises its historical population estimates when such changes are introduced, but it rarely re-estimates survey weights for past surveys.

The estimates shown for unauthorized immigrants and the underlying survey data are derived from ACS IPUMS 1% samples for 2005-16 and March CPS public-use files for 1995, 1998, 2000 and 2003, which have been reweighted to take into account population estimates consistent with the 1990, 2000 and 2010 censuses and the most recent population estimates. The population estimates used to reweight the ACS for 2005 through 2009 and the March 2003 CPS are the Census Bureau’s intercensal population estimates for the 2000s; these population estimates use demographic components of population change for 2000-10 and are consistent with both the 2000 and 2010 censuses. Similarly, the population estimates used to reweight the CPS for March 1995, 1998 and 2000 are the intercensal population estimates for the 1990s (U.S. Census Bureau, 2012a), which are consistent with the 1990 and 2000 censuses. The ACS data for 2010-16 do not require reweighting as they are weighted to recent population estimates based on the 2010 census. The original 2005 ACS covered the household population but not the population living in group quarters (about 8 million people). For Pew Research Center analyses, we augmented the 2005 ACS with group quarters records from the 2006 ACS but weighted to agree with the 2005 population estimates. The reweighting methodology for both the ACS and CPS follows, to the extent possible, the methods used by the Census Bureau in producing the sample weights that equal the population totals. See Passel, Cohn and Gonzalez-Barrera, 2013 for more details on weighting and adjustments for survey undercoverage.

Because of the much, much larger sample size in the ACS (more than 3.1 million sample cases in 2016 including more than 370,000 foreign-born cases) than the March CPS (185,000 sample cases in 2016 with about 24,000 foreign-born cases), the ACS-based estimates should be considered more accurate than the CPS-based estimates. In this publication, we have replaced the previously published CPS-based estimates for years from 2005 onward with ACS-based estimates.

Other methodological issues

Adjustment for undercount

Adjustments for omissions from the surveys (also referred to as adjustments for undercount) are introduced into the estimation process at several points. The initial comparisons with the survey (based on the equation shown above) take the difference between the immigrants in the survey and the estimated lawful immigrant population. Since the comparison is people appearing in the survey, the estimated lawful immigrant population must be discounted slightly because some lawful immigrants are missed by the survey. This initial estimate represents unauthorized immigrants included in the survey. To estimate the total number of unauthorized immigrants in the country, it must be adjusted for those left out. Similarly, the estimated number of lawful immigrants appearing in the survey must be adjusted for undercount to arrive at the total foreign-born population.

These various coverage adjustments are done separately for groups based on age, sex, country of birth and year of arrival. The patterns and levels of adjustments are based on U.S. Census Bureau studies of overall census coverage (see U.S. Census Bureau, 2012a for links to evaluation studies of the 1980, 1990, 2000 and 2010 censuses; also Passel, 2001) that are adjusted up or down to reflect the results of a number of specialized studies that focus on immigrants. Census Bureau undercount estimates have generally been subdivided by race/Hispanic origin, age, and sex. So, the adjustments to the Pew Research Center data use rates for countries of birth based on the predominant race of immigrants from the country – Hispanic and non-Hispanic races for white, black and Asian. Undercount rates for children do not differ by gender, but for younger adults (ages 18 to 29 and 30 to 49) the undercount rates for males tend to be higher, and for some groups much higher, than those for females. At older ages, the undercount rates are lower than for younger adults with no strong patterns of gender differences (and with some estimated overcounts).

The basic information on specific coverage patterns of immigrants is drawn principally from comparisons with Mexican data, U.S. mortality data and specialized surveys conducted at the time of the 2000 census (Van Hook et al., 2014; Bean et al., 1998; Capps et al., 2002; Marcelli and Ong, 2002). In these studies, unauthorized immigrants generally have significantly higher undercount rates than lawful immigrants who, in turn, tend to have higher undercounts than the U.S.-born population. More recent immigrants are more likely than longer-term residents to be missed. The most recent study (Van Hook et al., 2014) finds marked improvements in coverage of Mexicans in the ACS and CPS between the late 1990s and the 2000s. This and earlier work suggest very serious coverage problems with immigrants in the data collected before the 2000 census but fewer issues in the 2000 census and subsequent datasets. This whole pattern of assumptions leads to adjustments of 10% to 20% for the estimates of unauthorized immigrants in the 1995-2000 CPS, with slightly larger adjustments for unauthorized Mexicans in those years. (Note that this means even larger coverage adjustments, sometimes exceeding 30% for adult men younger than age 40.)

After 2000, the coverage adjustments build in steady improvements in overall coverage and improvements specifically for Mexican immigrants. The improvements are even greater than noted in the research comparing Mexico and U.S. sources because the reweighted ACS and CPS data imply significant improvements in reducing undercounts, since they incorporate results of the 2010 census. With all of these factors, coverage adjustments increase the estimate of the unauthorized immigrant population by 8% to 13% for 2000-09 and by 5% to 7% for 2010-16. For the overall immigrant population, coverage adjustments hovered slightly below 5% during the 1990s and trended downward to around 2% to 3% by 2014. Since the population estimates used in weighting the ACS and the CPS come from the same sources, the coverage adjustments tend to be similar.

State estimates

The initial estimates of unauthorized immigrants for states other than the six largest (California, Texas, Florida, New York, Illinois and New Jersey) arise from the tabulated totals of the individual microdata records assigned as unauthorized immigrants. The overall trends at the state level are assumed to progress somewhat smoothly from one year to the next, though the initial estimates based on status assignments may not behave in exactly that way. Accordingly, the final estimated state totals for any given year take into account estimates for surrounding years; however, only a small number of state estimates require significant adjustment based on the trend analysis. The last step in developing the individual weights for the unauthorized immigrants involves adjusting the initial weights in each state to agree with the totals from the trend analysis. The largest adjustments are in those states where the trend analysis showed a substantial difference between the initial estimates and the trend analysis. Nonetheless, all states are adjusted so that the state totals agree as closely as possible with either the initial estimate or the trend-based estimate. At the same time, the adjustment is done so that the national totals of the state populations agree with the residual estimates for the total unauthorized immigrant population and the totals from each of the four broad regions of birth.

Compared with the most recent previously published estimates, the estimates published here bring in two additional years of ACS-based estimates, 2015 and 2016. With these new data, some state totals for the last two years in the previous publication, 2013 and 2014, have been revised (Passel and Cohn, 2016). This earlier report has further discussion of how the state trend analysis affected estimates for years before 2013.

Margins of error

Estimates of the unauthorized immigrant population are computed as the difference between a deterministic, administratively based estimate (i.e., the lawful foreign-born population, or “L” in the equation above) and a sample-based estimate (i.e., the survey total of the foreign-born population, or “F”). Consequently, the margin of error (or variance) for the estimated unauthorized population is the margin of error for “F,” the sample-based estimate of the foreign-born population. Thus, the margins of error are generally based on the variance of the foreign-born population entering since 1980.

For all years of the ACS, variances are computed with replicate weights supplied by the U.S. Census Bureau through IPUMS; for earlier CPS data, generalized variance formulas supplied in Census Bureau documentation were used to compute margins of error.

The ranges reported represent a 90% confidence interval around the estimates. They represent the sampling error associated with the survey-based estimate. Other sources of potential error – including the variability associated with the random assignment of statuses, potential errors in the status assignment process and non-sampling error in the surveys – are not represented in the reported margins of error. For this report, statistical tests rely on a 90% confidence level.

Countries and regions of birth

Some modifications in the original CPS countries of birth were introduced to ensure that all foreign-born respondents could be assigned to a specific country or region of birth. See Passel and Cohn (2008) for a detailed treatment of how persons with unknown country of birth were assigned to specific countries.

Defining regions of the world and, in some cases, specific countries using the various data sources requires grouping areas into identifiable units and “drawing lines” on the world map. In the historical data used to construct the lawful foreign-born population, it is not possible to differentiate the individual republics within the former Soviet Union. In both the CPS and ACS microdata, not all the individual republics can be identified; some are identified in some years but not others. However, a code is assigned for USSR in all years, even when the USSR no longer existed. Thus, for analytic purposes in this report, the former republics are grouped together and considered to be part of Europe.

For this report, China, Hong Kong and Taiwan are combined and reported as “China” because of potential inconsistencies between the administrative data sources and the surveys and because of concerns over consistency of reporting on the part of respondents. South and East Asia is defined to include Afghanistan, Pakistan and countries east of them. The Middle East comprises Southwest Asia from Iran and westward to Turkey and Cyprus plus countries in North Africa. “Africa” comprises sub-Saharan Africa —the rest of the continent. Data for North and South Korea are not generally separated in the survey data used for the estimates. Thus, estimates reported for persons born in Korea cover both North and South Koreans; the vast majority of Korean immigrants in the U.S. are from South Korea. A small number of unauthorized immigrants are from Oceania and from a residual “Other” category shown in ACS data. The total of the residual “other” and Oceania is included in the overall national estimates but not shown separately in any tables or figures.

Labor force and workers

The labor force includes all people ages 16 and older who are working or looking for work. For the analyses of occupations and industries, we exclude people who did not report an occupation or industry. In our analysis, we also exclude people in the military or with a military occupation. These exclusions drop about less than 2% of the total labor force of roughly 164 million – 2.4 million are excluded from the occupation analyses and 2.9 million from the industry analyses. About 95,000 unauthorized immigrants, or 1.2% of those in the workforce, are excluded from this analysis because they do not report an occupation or industry; unauthorized immigrants are generally not eligible to be in the military or to hold military employment, so they are not excluded for that reason. Unemployed people are only excluded if they do not report an occupation or industry, although most do report one.

Industry and occupation category labels

The U.S. Census Bureau has three levels of aggregation each for industry and occupation. At the highest level are 12 classifications for “major occupation” groups (11 for civilians, plus the armed forces). At the next level are 23 “detailed occupation” groups, though eight of them are identical to the “major” groups; the three major occupation groups for management, professional and service occupations are subdivided into 15 smaller, detailed groups. Finally, there are a large number of very specific occupation categories – almost 600 – that can be grouped into either the “detailed” or “major” groups. So, for example, the code for “aerospace engineers” (1320) is part of the detailed category for “architecture and engineering occupations” which, in turn, is part of the major category of “professional and related occupations.”

For industries, the highest level has 14 “major industry” groups (13 for civilians and one for the armed forces). At the next level are 52 “detailed industry” groups. Unlike with occupations, only four of the “major” groups are identical to “detailed” groups. Finally, there are 273 very specific industry categories that can be grouped into either the “detailed” or “major” groups. So, for example, the industry called “retail bakeries” (code 1190) is part of the detailed category for “food manufacturing” which, in turn, is part of the major category of “manufacturing.”

The analyses presented here use the “major” categories for both occupations and industries. Some data are presented for the very specific occupations and industries with the highest concentrations of unauthorized immigrants.

For ease of presentation, the full titles of many industry and occupation categories have been condensed from the Census Bureau’s terminology in some figures and text. If so, they are shortened as follows:

Agriculture, forestry, fishing, and hunting Agriculture
Mining
Construction
Manufacturing
Wholesale and retail trade Wholesale/retail
Transportation and utilities Transport/utilities
Information
Financial activities
Professional and business services Business services
Educational and health services Education/health
Leisure and hospitality Leisure/hospitality
Other services
Public administration

Data on “major” occupation categories are sometimes condensed in figures and the text. If so, they are shortened as follows:

Management, business, and financial Management
Professional and related Professional
Service
Sales and related Sales
Office and administrative support Office support
Farming, fishing, and forestry Farming (or Agriculture)
Construction and extraction Construction
Installation, maintenance, and repair Maintenance
Production
Transportation and material moving Transportation

References in the text, text charts and tables can be cross-referenced to the lists above.

More information on the Census Bureau’s industry and occupation categories can be found here: https://www.census.gov/topics/employment/industry-occupation/guidance/indexes.html

Children, adults and spouses

In this report, the term “spouse” encompasses both married couples and unmarried partners. Because of limitations in reporting family relationships in the ACS, essentially all unmarried partners involve the individual who is called the head of a household and not other couples within the household.

In most uses in this report, “children” are defined as individuals younger than 18 who are not the head or spouse in a family unit. This means that individuals younger than 18 who have their own children or are the spouse/partner of another household member are not included in the child population. “Adults” are people who are not “children,” that is, they are 18 years old or older or are a parent/spouse/partner of someone else in the household.

Small modifications to these definitions are made in defining “U.S.-born children of unauthorized immigrants” and “unauthorized immigrant children.” First, these groups comprise all individuals under 18 who are the child of an unauthorized immigrant in the household even if the child is a parent or spouse/partner themselves. More than 99% of individuals classified as children of unauthorized immigrants fit this definition. Then, individuals under 18 who live in households where the only adult(s) are an unauthorized immigrant or a couple in which one or both are unauthorized immigrants; further, an adult is a relative of the child. This group accounts for about 45,000 of the 5 million U.S.-born children of unauthorized immigrant in 2016 and about 4,000 of the 675,000 unauthorized immigrant children. Finally, the 5 million U.S.-born children of unauthorized immigrants include about 10,000 children who are actually lawful immigrants with an unauthorized immigrant parent.

Adult children of unauthorized immigrants are individuals aged 18 and older who live in a household with at least one parent who is an unauthorized immigrant. People (either 18 and older or under 18) who have an unauthorized immigrant parent but do not live with an unauthorized immigrant parent cannot be classified as the child of an unauthorized immigrants because there is no information in the census data linking them with their parents. Thus, the estimates presented here for children of unauthorized immigrants are smaller than the number of people who have an unauthorized immigrant parent.