Immigration Issues

How Many Illegal Immigrants? (2011)

FAIR estimates that in 2010 the illegal alien population is almost 12 million persons. Government and academic sources estimate the illegal immigrant population at about 11 million residents.

It is difficult to have an exact figure for the illegal alien population, because their illegal presence prevents any accurate enumeration, but all estimates coincide in the fact that the illegal alien population grew rapidly during the early part of the past decade by as much as half a million persons per year — before leveling off and declining slightly at the end of the decade.

Composition and Distribution of the Illegal Immigrant Population

In 2000, the INS absorbed into the Department of Homeland Security (DHS) in 2002 estimated the illegal alien population at 7 million. The U.S. Census Bureau estimated the 2000 population of illegal aliens at about 8.7 million residents. By 2005 the DHS estimate had increased to 10.76 million and by 2007 to 11.78 million. The DHS estimate subsequently decreased as border control efforts increased and job opportunities decreased. In 2010 the DHS estimate of the illegal alien population was 10.79 million.

Another often cited estimate of the illegal alien population is from the Pew Hispanic Center, a research institute. Its estimates have been roughly similar to those of the DHS. For example, in 2005 the Pew estimate of the illegal alien population was 10.8 million increasing to 11.96 million in 2008 and then falling to 11.2 million in 2010.

FAIR’s estimate of the illegal alien population in 2007 was 13 million. Thus our estimates have paralleled those of DHS and Pew, but have been slightly higher. Our view is that the official estimate of the illegal alien population is understated because it excludes recently arrived illegal aliens and illegal aliens that have been given a temporary reprieve from deportation in the Temporary Protected Status (TPS) program.

Other Estimates

In the August 2001 issue of Demography, immigration researchers estimated the current total population of illegal immigrants at 7.1 million, of whom 3.9 million were Mexicans. Also in August 2001, a demographer at the Urban Institute issued an estimate that the illegal immigrant population was 8.5 million, with 4.5 million of them being Mexican.

In 2005, an independent estimate by analysts of the Bear-Stearns investment firm said the illegal immigrant population "...may be as high as 20 million people."¹ This estimate dismissed lower official estimates as being flawed by the non-response of illegal immigrant to Census takers. However, this conclusion missed the fact that the official estimates were instead based on a comparison between the growth in the foreign-born population and new legal immigrant arrivals. This allows the trend in the illegal immigrant population to be observed despite non-response in the Census.

TIME Magazine in a feature article in 2004 published an estimate of three million illegal immigrants arriving each year.² That estimate was based on a mistaken assumption that a million illegal immigrants were being apprehended each year and three times as many avoided apprehension. The actual number of persons apprehended was at that time considerably lower than one million because the same individual often may be apprehended multiple times during the year.

Nationality of Illegal Aliens

The nationalities of the illegal immigrant population in 2000 as estimated by DHS and the Census Bureau and in 2010 by DHS are as follow:

Although the 2000 estimates by nationality vary, they coincide in identifying Mexico as by far the largest source of the illegal alien population with Central American countries also primary sources for this population.

Distribution of Illegal Aliens by State

The following table shows estimates of the illegal immigrant population by state by DHS³ and the Pew Hispanic Center⁴ as well as the current estimates by FAIR. (Numbers are thousands).