September 23, 2013

Population Decline of Unauthorized Immigrants Stalls, May Have Reversed

New Estimate: 11.7 million in 2012

1. Overview

Estimates of the U.S. Unauthorized Immigrant Population, 1990-2012The sharp decline in the U.S. population of unauthorized immigrants that accompanied the 2007-2009 recession has bottomed out, and the number may be rising again. As of March 2012, 11.7 million unauthorized immigrants were living in the United States, according to a new preliminary Pew Research Center estimate based on U.S. government data.

The estimated number of unauthorized immigrants peaked at 12.2 million in 2007 and fell to 11.3 million in 2009, breaking a rising trend that had held for decades. Although there are indications the number of unauthorized immigrants may be rising, the 2012 population estimate is the midpoint of a wide range of possible values and in a statistical sense is no different from the 2009 estimate.

Different trends appear among the six states in which 60% of unauthorized immigrants live—California, Florida, Illinois, New Jersey, New York and Texas.1 Of these, only Texas had increases but no decrease in its unauthorized immigrant population over the 2007-2011 period. The other five states (and the balance of the country) all experienced peak numbers of unauthorized immigrants in 2007 followed by declines over the next year or two.

In terms of country of origin, the post-2007 population dip was even sharper among Mexicans (who made up 52% of 2012 unauthorized immigrants) than the overall population decrease, although the Mexican decline appears to have stopped after 2010. In 2012, 6.05 million Mexican unauthorized immigrants were in the U.S., a decline of about 900,000 from 2007.

Methods and Cautions

The new Pew Research estimates rely on the center’s residual methodology, in which legal immigration is subtracted from the adjusted total foreign-born population to arrive at a total for unauthorized immigrants. These estimates slightly revise previously published estimates for 2000-2011 (Passel and Cohn, 2012a) to account for new findings from the 2010 Census. This report also presents the initial, direct residual estimates that cover six individual states and aggregate the rest of the country; more detailed estimates for the remaining states and for characteristics of the unauthorized immigrant population are developed from these estimates and will be available in a later report.

These estimates also introduce a new data source for the Pew Research estimates—the U.S. Census Bureau’s American Community Survey (ACS) for 2005 to 2011, replacing the March Current Population Survey (CPS) for those years. The ACS has about 12 times more sample cases than the CPS and thus provides more precise estimates with smaller margins of error.

In analyzing recent year-to-year change, especially at the state level, this report focuses on 2005 to 2011 (especially 2007 to 2011) because the large sample size for ACS-based estimates permits more statistically sound statements about annual differences than was possible with the previously published estimates. The 2012 CPS-based estimates are derived from a much smaller sample, resulting in margins of error generally too large to draw conclusions about change from 2011 to 2012. These 2012 CPS estimates should be treated as preliminary because they will be replaced with ACS-based estimates when the 2012 ACS microdata become available later this year. (See Methodology for more details.)

Comparison with Previous Estimates

Estimates presented here of the unauthorized immigrant population replace those previously published by the Pew Research Center for 2000 to 2011 (Passel and Cohn, 2012a). The figures for the foreign-born population used in these new estimates are drawn from two U.S. government surveys—the March Supplement to the Current Population Survey (CPS) and the American Community Survey (ACS). Those surveys are, in turn, tied to the Census Bureau’s estimates of the population during the survey period. At the time the surveys are released by the Census Bureau, they incorporate the most recent official population estimates.

After the release of 2010 Census results, the Census Bureau issued a set of new population estimates that incorporated updated information about population change over the previous decade. The same process took place after the 1990 and 2000 censuses. However, the Census Bureau generally does not return to previously released ACS, CPS or other survey data to incorporate updated information from these revised intercensal population estimates.

In the interest of greater accuracy, the Pew Research Center developed new survey estimates for the 2005-2009 ACS and the 2000-2010 March CPS that are consistent with the results of both the 2000 and 2010 censuses; for March 2011 consistent with the 2010 Census; and for March 1995-1999 consistent with both the 1990 and 2000 censuses. These new survey estimates are based on the Census Bureau’s revised annual intercensal population estimates, i.e., those that are consistent with both the preceding and subsequent censuses.

Those new survey estimates are the basis for the new unauthorized immigrant numbers presented in this report. The new estimates of the unauthorized immigrant population generally show the same trends over time as the previous estimates but at slightly higher levels for some years (notably in the 1990s and second half of the 2000s). Users are cautioned that previous estimates should not be compared with those in this report.

Other Evidence

Border Patrol Apprehensions of Unauthorized Immigrants, 1995-2012Additional evidence about trends in unauthorized immigration comes from U.S. government data on border apprehensions.

Driven by unauthorized immigration from Mexico, U.S. Border Patrol apprehensions rose through the 1990s and peaked at 1.7 million in fiscal 2000. After reaching somewhat lower levels for 2001-2007, apprehensions fell dramatically from 2007 to 2011. In 2012, the number of unauthorized immigrants apprehended at the Mexican border rose modestly, to 365,000, but only because of growing apprehensions of non-Mexicans; apprehensions of Mexicans continued to decline.

About this Report

This report provides estimates of the size of the March 2012 unauthorized immigrant population for the nation, as well as for the six states (California, Florida, Illinois, New Jersey, New York and Texas) where 60% of unauthorized immigrants live. For the nation, it also shows estimates of the size of the unauthorized immigrant population from Mexico and from all other countries. For the nation, the six states and the balance of the country, the report also includes annual estimates of the unauthorized immigrant population for 1995-2012 and an estimate for 1990. Estimates for those years at the national level also are provided for the unauthorized immigrant population from Mexico and all other countries.

The Pew Research Center’s Hispanic Trends Project estimates the unauthorized immigrant population using a residual method, which is based on official government data. Under this methodology, a demographic estimate of the legal foreign-born population—naturalized citizens, legal permanent residents, temporary legal residents and refugees—is subtracted from the total foreign-born population as measured in a survey. The remainder, or residual, is the source of population estimates and characteristics of unauthorized immigrants.

The estimates use data from the Current Population Survey (CPS), conducted by the Bureau of Labor Statistics and the Census Bureau, and from the American Community Survey (ACS), conducted by the Census Bureau. The March Supplement to the CPS, a survey of about 80,000 households for 2001 and later versus about 50,000 households earlier, is the source of data for 1995-2004 and for 2012. The ACS, a compilation of monthly data including about 3 million households each year, is the source of data for 2005-2011. The Pew Research Center’s Hispanic Trends Project’s estimates make adjustments to the government data to compensate for undercounting, and therefore its population totals differ somewhat from the ones the government uses. Estimates for any given year are based on a March reference date for years from the CPS and a July 1 reference date for years from the ACS.

These estimates are not consistent with previously published Pew Research Center estimates of the unauthorized immigrant population. The previous unauthorized immigrant numbers are based on survey data tied to previous Census Bureau population estimates that have since been revised. The Pew Research Center revised the historic survey data so those data conform to updated Census Bureau population estimates. The resulting series of unauthorized immigrant estimates are consistent over time but inconsistent with previous estimates. See Methodology for more details.

Accompanying this report are an interactive graphic and a slide show about overall unauthorized immigration trends.

This report was written by senior demographer Jeffrey S. Passel, senior writer D’Vera Cohn and research associate Ana Gonzalez-Barrera. Research analyst Eileen Patten created the charts and tables. Research assistant Anna Brown number-checked the report. Marcia Kramer was the copy editor.

The authors appreciate the guidance of Paul Taylor, executive vice president of the Pew Research Center, and of Mark Hugo Lopez, the center’s director of Hispanic research.

A Note on Terminology

“Foreign born” refers to an individual who is not a U.S. citizen at birth or who, in other words, is born outside the U.S., Puerto Rico or other U.S. territories and whose parents are not U.S. citizens. The terms “foreign born” and “immigrant” are used interchangeably. “U.S. born” refers to an individual who is a U.S. citizen at birth, including people born in the United States, Puerto Rico or other U.S. territories, as well as those born elsewhere to parents who are U.S. citizens. The U.S.-born population is also called the “native population.”

The “legal immigrant” population is defined as people granted legal permanent residence; those granted asylum; people admitted as refugees; and people admitted under a set of specific authorized temporary statuses for longer-term residence and work. This group includes “naturalized citizens,” legal immigrants who have become U.S. citizens through naturalization; “legal permanent resident aliens” who have been granted permission to stay indefinitely in the U.S. as permanent residents, asylees or refugees; and “legal temporary migrants” who are allowed to live and, in some cases, work in the U.S. for specific periods of time (usually longer than one year).

“Unauthorized immigrants” are all foreign-born non citizens residing in the country who are not “legal immigrants.” These definitions reflect standard and customary usage by the U.S. Department of Homeland Security and academic researchers. The vast majority of unauthorized immigrants entered the country without valid documents or arrived with valid visas but stayed past their visa expiration date or otherwise violated the terms of their admission. Some who entered as unauthorized immigrants or violated terms of admission have obtained work authorization by applying for adjustment to legal permanent status or by obtaining Temporary Protected Status (TPS). Data are very limited, but this “quasi-legal” group could account for as much as 10% of the unauthorized population. Many could also revert to unauthorized status.

“Removals” are the compulsory and confirmed movement of inadmissible or deportable aliens out of the United States based on an order of removal. An alien who is removed has administrative or criminal consequences placed on subsequent re-entry. The Department of Homeland Security uses the term “removal” rather than “deportation” to describe the actions of its Immigration and Customs Enforcement (ICE) and Customs and Border Protection (CBP) to expel foreign nationals from the country. “Deportations” are one type of removal and refer to the formal removal of a foreign citizen from the U.S. In addition, a foreign citizen may be expelled under an alternative action called an expedited removal. The Illegal Immigration Reform and Immigrant Responsibility Act of 1996 allows U.S. immigration authorities to issue an expedited order of removal and directly remove a foreign citizen without referral to an immigration judge under certain circumstances. Deportations and expedited removals together comprise removals reported by the Department of Homeland Security.

Cite this publication: Jeffrey S. Passel, D’Vera Cohn and Ana Gonzalez-Barrera. “Population Decline of Unauthorized Immigrants Stalls, May Have Reversed.” Pew Research Center, Washington, D.C. (September 23, 2013) http://www.pewhispanic.org/2013/09/23/population-decline-of-unauthorized-immigrants-stalls-may-have-reversed/, accessed on July 23, 2014.

  1. These six states had the largest unauthorized immigrant populations when the Pew Research Center’s methodology for estimating such immigration was developed, and were the only states with large enough survey samples from which to develop reliable estimates at that time. With the geographic dispersal of the unauthorized immigrant population, other states may now have larger populations than some of these six. Estimates for the remaining 44 states, and the District of Columbia, will be released in a subsequent report.