Illegal immigrant population of the United States
The actual size and the origin of the illegal immigrant population in the United States is uncertain and is difficult to ascertain because of difficulty in accurately counting individuals in this population. Figures from national surveys, administrative data and other sources of information vary widely. Two analyses by the Center for Immigration Studies of U.S. Census data estimate the illegal immigrant population in 2015 ranged from 10.9 million to 15.7 million. The Pew Research Center indicates that there were 11.3 million illegal immigrants in the U.S in 2014.
The "residual method" is widely used to estimate the unauthorized immigrant population of the US. With this method, the known number of legally documented immigrants to the United States is subtracted from the reported U.S. Census number of self-proclaimed foreign-born people (based on immigration records and adjusted by projections of deaths and out-migration) to obtain the total, unauthorized immigrant (residual) population. This methodology is used by the US Department of Homeland Security, the Pew Hispanic Center, the Center for Immigration Studies, and the US Census Bureau. Since unauthorized immigrants have many reasons for not answering the U.S. Census correctly and since there are no penalties for answering the U.S. Census incorrectly, it is accepted that it under-counts the number of illegal immigrants. The users of this methodology assume that 10% of illegal immigrants are not counted by census takers. The 10% assumption is based on a 2001 University of California survey asked of 829 people born in Mexico and living in Los Angeles whether they responded to census interviewers in the 2000 census with 40% of queried households refusing to answer the survey. Critics claim that the estimate is unreliable for a number of reasons: figures for outmigration are not tracked by the federal government; the proportion of undocumented immigrants who respond to the Census is unknown; the estimate that 10% of illegal immigrants do not respond to the census is arbitrary and unsupported by a sufficient sample size and geographic spread; and that the self reporting of where one was born relies on the honesty of the person being questioned.
Using the residual methodology with a minimal 10% foreign born under-count correction (reason for correction size unstated) for the 2000 census, a 700,000 net illegal immigrant increase/year assumption and data from the March 2004 Current Population Survey, Pew estimated that there were 10.3 million illegal immigrants in the US in 2004. Assuming the same rate of growth, Pew projected this population reached at least 11 million as of March 2005.
The Pew Hispanic Center estimates that, in the 1980s, the net advance of the U.S. illegal immigrant population was at 130,000 per year, increasing to 450,000 per year from 1990 through 1994, further increasing to 750,000 per year from 1995 through 1999, and staying at 700,000 to 850,000 or more per year since about 2000. Illegal Mexican immigration amounts to about 500,000 per year of this influx since about 1999. According to the same Pew Hispanic Center study, as of March 2005, the illegal U.S. population had reached 11 million or more, including more than 6.5 million illegal Mexican immigrants, which is around 60% of all unauthorized immigrants. Assuming the same rate of growth as in recent years gives around 12 million illegal immigrants in the United States as of January 2006, increasing at 700,000–850,000 per year—with illegal Mexican immigrants amounting to about 60%+ (over 7 million) of the overall total by 2006. By September 2006, the illegal immigrant U.S. population was thought to be around 13 million. About one-sixth of the illegal immigrant population—about 1.7 million people as of 2005[update]—is under 18 years of age.
In 2006, legal immigrants to the United States numbered approximately 1,000,000 per year—of which about 600,000 were Change of Status immigrants who were already in the US. Legal immigrants to the United States are now[when?] at their highest level ever at over 35,000,000. Net advances by illegal immigrants into the USA have also increased from about 130,000 per year in the 1970s, to 300,000 or more per year in the 1980s, to over 500,000 per year in the 1990s, to over 700,000 per year in the 2000s. Total entrance by unauthorized immigrants into the US may have been as high as 1,500,000 per year in 2006—with a net of at least 700,000 more unauthorized immigrants arriving each year to join the 12,000,000 to 20,000,000 that were already in the US. 
Pulitzer prize-winning investigative journalists Donald L. Barlett and James B. Steele estimated in Time magazine (in its September 12, 2004, issue) that the number of unauthorized immigrants entering into the US that year would total 3 million based on Department of Homeland security estimates that only one out of four illegal immigrants is apprehended at the border.
Bear Stearns' method
|Mexican remittances and undocumented population growth|
|Non-Mex.||4.0 to 6.0|
|Total illegal aliens estimated by Bear Stearns||20.0 to 22.0 million**|
|Assumes the amount of remittances from the US is proportional to the number of Mexicans living in the US.
As can be seen the Pew and Bear Stern numbers are in basic agreement until around the year 2000.
Total remittances in 2005 were around $20 billion.
In 2005, Bear Stearns' investigators developed a different methodology to determine the number of illegal immigrants in the United States. They made the assumption that the amount of remittances (money sent back to Mexico) is directly proportional to the number of Mexican immigrants in the United States. Other data used for their estimates are the increases of households and school enrollment in Mexican immigrant communities. They conclude that the number of illegal immigrants in the United States may well be twice the official number put out by the U.S. Census of 9 million and may be 20 million people or higher. Information from The Mexican Central Bank details the remittances and shows their growth.
According to that data, remittances stayed fairly stable until 2000 when a steady and dramatic increase began. The change in remittances between 1997 and 1999 is most likely a problem in accounting—the three year average is still about 450 thousand/year consistent with other data. The agreement with the Pew estimate is reasonably good up to 2001 where there is a significant difference—just where the Pew and Census data becomes harder to extrapolate because of lack of good data. Using this technique Bear Sterns investigators come up with a possible illegal immigrant population of 20 million or greater. (See figure for calculation) Other data confirming their estimates are the dramatic increases of households and school enrollment in Mexican immigrant communities (read their report for more details). Border Arrest data do not show this dramatic increase in apprehensions.
Impact of the global financial crisis of 2008–2009
The 2008 global financial crisis has had a large impact on America. The construction sector and other areas illegal immigrants traditionally seek employment in shrunk. The recession also led to a surplus of American labor, driving down the benefit of hiring illegal immigrants. According to the Pew Research Center, In 2007 the number of unauthorized Mexican immigrants peaked at 6.9 million and has dropped by more than 1 million to an estimated 5.6 million in 2014.
In 2005, according to a Pew Hispanic Center report, there were about 6,840,000 illegal immigrants from Mexico making 56% of immigrants present in the United States illegally. 24% were from other Latin American countries; 9% were from Asia, 6% from Europe and Canada, and the remaining 4% from the rest of the world. In 2014, the Pew Hispanic Center estimated that the illegal immigrant population from Mexico had reduced to 5.6 million or 49% of the undocumented immigrant population.
|Country of origin (January 2006)|
|Latin and Central America||3,000,000||24%|
|Europe and Canada||720,000||6%|
|Rest of World||480,000||4%|
The number of Mexican legal and illegal immigrants in the United States grew quite rapidly over the 35 years between 1970 and 2004; increasing almost 15-fold from about 760,000 in the 1970 Census to more than 11 million in 2004—an average annual growth rate of more than 8 percent, maintained over more than three decades. On average the net Mexican population, both legal and illegal, living in the United States has grown by about 500,000 per year from 1995 to 2005 with 80 to 85 percent of the growth attributed to illegal immigration. There was a net gain of 2,270,000 Mexican immigrants to the US between 1995 and 2000; a net loss of about 20,000 between 2005 and 2010; and a net loss of 140,000 between 2009 and 2014.
The total number of Mexicans residing in the US, with and without authorization, was 11.7 million in 2014, down from the peak of 12.8 million in 2007. The drop is primarily the result of the decrease in the number of unauthorized migrants—which make up 48% of the Mexican population in the US in 2014, down from 54% in 2007.
- "Record 61 million immigrants in U.S., 15.7 million illegally". WashingtonExaminer.com. Retrieved December 27, 2016.
- "U.S. illegal immigrant population falls below 11 million, continuing nearly decade-long decline, report says". WashingtonPost.com. January 20, 2016. Retrieved December 27, 2016.
- "5 facts about illegal immigration in the U.S.". PewResearch.org. November 3, 2016. Retrieved December 27, 2016.
- Jeffrey S. Passel (June 2005). "Unauthorized Migrants: Numbers and Characteristics" (PDF). Pew Hispanic Center. p. 7.
- Michael Hoeffer; Christopher Campbell; Nancy Rytina (January 2015). "Estimates of the Unauthorized Immigrant Population Residing in the United States: May 2006" (PDF). US Department of Homeland Security, Office of Immigration Statistics, Policy Directorate.
- Bialik, Carl (May 8, 2010). "In Counting Illegal Immigrants, Certain Assumptions Apply". Retrieved December 27, 2016 – via Wall Street Journal.
- "Unauthorized immigrant population stable for half a decade". Pew Research Center. September 21, 2016. Retrieved November 10, 2016.
- PEW 2005, p. 1
- Steven Malanga (Summer 2006). "How Unskilled Immigrants Hurt Our Economy".
- "Gauging Illegal Immigration Numbers". npr.org. Retrieved December 27, 2016.
- Donald L. Barlett; James B. Steele (September 20, 2004). "Who Left the Door Open?". Time. p. 5.
* Banco de Mexico
** Bear Stern's investigators
***PEW 2005[not in citation given]
- "CPSS-WB General Principles for International Remittances Services: The Point of View of Authorities: Banco de México" (PDF). The World Bank. May 2006.
- Preston, Julia (July 31, 2008). "Decline Seen in Numbers of People Here Illegally". The New York Times. Retrieved May 5, 2010.
- Gonzalez-Barrera, Ana. "More Mexicans Leaving Than Coming to the U.S.". Pew Research Center. Retrieved August 4, 2016.
- Jeffrey S. Passel (March 7, 2006). "Pew Hispanic Center: "The Size and Characteristics of the Unauthorized Migrant Population in the U.S. – Estimates Based on the March 2005 Current Population Survey"" (PDF).
The Mexican-born population in the United States, including both legal and unauthorized migrants, grew by about 500,000 people a year for the past decade. Of the Mexican migrants in the U.S. less than 10 years, the Pew Hispanic Center estimates that approximately 80 to 85% are unauthorized