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Has the Unauthorized Immigrant Population Leveled Off?

By Matt Graham

Thursday, April 24, 2014

Today, the U.S. Department of Homeland Security (DHS) released an updated estimate of the unauthorized immigrant population. As of January 1, 2012, DHS estimated that 11.4 million unauthorized immigrants were in the country (Figure 1). By comparison, the Pew Research Center’s commonly-cited estimates suggest that about 11.7 million unauthorized immigrants were in the country as of March 2012.

Figure 1. DHS and Pew estimates of the unauthorized immigrant population1

Unauthorized immigrant population

Note: DHS estimates combine data from the American Community Survey, the U.S. Census, and other sources. DHS published two different estimates for the 2010 population to show the difference between the 2000 and 2010 Censuses.

Both DHS and Pew provide 90 percent confidence intervals for their estimates. DHS’ confidence interval was plus or minus 125,000 while Pew’s interval was 11.1 million to 12.2 million. This means that statistically, there is no significant difference between the two 2012 estimates. Pew’s confidence interval is larger because it bases estimates on the Current Population Survey, which has a smaller sample than DHS estimates based on the American Community Survey.

The new DHS figures suggest that the conventional wisdom that the unauthorized immigrant population began to increase after the recession may not be correct. According to DHS’s estimates, the unauthorized immigrant population declined slightly between 2010 and 2012. Pew’s estimates suggest that it rose over that period, but the change was not statistically significant from 2010 (or 2009). DHS’s estimate of a decline is statistically significant, but just barely. Although DHS’ estimate carries slightly more confidence than Pew’s, neither resolves the question conclusively.

It is important to be mindful that these estimates are two years old, and that the recent uptick in southwest border apprehensions suggests that some increase in the unauthorized population could have occurred in 2013. Based on the available information, however, it may be most accurate to say that the unauthorized population remained about the same after the 2007-2009 decline, and that it is unclear whether a marginal increase or decrease has occurred since the end of the recession.


1 DHS (2014), “Estimates of the Unauthorized Immigrant Population Residing in the United States: January 2012,” available at http://www.dhs.gov/sites/default/files/publications/ois_ill_pe_2012_2.pdf. Pew Research Center (2013), “Population Decline of Unauthorized Immigrants Stalls, May Have Reversed,” available here.

KEYWORDS: DEPARTMENT OF HOMELAND SECURITY, PEW RESEARCH CENTER