Estimates of the Unauthorized Immigrant Population Residing in the United States: January 2011 Department of Homeland Security:
The unauthorized immigrant population is the remainder or “residual” after the legally resident foreign-born population -
- legal permanent residents (LPRs),
- naturalized citizens,
- and nonimmigrants
- is subtracted from the total foreign-born population.
Data to estimate the legally resident population were obtained primarily from the Department of Homeland Security (DHS), whereas the American Community Survey (ACS) of the U.S. Census Bureau was the source for estimates of the total foreign-born population.
In summary, an estimated 11.5 million unauthorized immigrants were living in the United States in January 2011 compared to a revised 2010 estimate of 11.6 million.
In general, caution is recommended in interpreting changes in the size of the unauthorized population presented in this report.
Annual estimates of the unauthorized immigrant population are subject to sampling error in the ACS and considerable nonsampling error because of uncertainty in some of the assumptions required for estimation (see Limitations below).
METHODOLOGY AND DATA:
Two populations are estimated in order to derive the unauthorized
- 1) the total foreign-born population living
in the United States on January 1, 2011 and
- 2) the legally resident
population on the same date.
The unauthorized population is equal
to 1) minus 2).
Assumptions about undercount of the foreign-born population in the ACS and rates
Accuracy of year of entry reporting
Assumptions about the nonimmigrant population estimate
Sampling error in the ACS
Accuracy of state of residence for the non-naturalized legally resident population
- An estimated 11.5 million unauthorized immigrants were living in the United States in January 2011
- The DHS report does discuss limitations/errors in estimates
For more detailed information about the estimates and their limitations click the link above.