Unauthorized Immigration to the United States: Annual Estimates and Components of Change, by State, 1990 to 2010


  • This report and the estimates herein would not have been possible without the contributions of Michael Hoefer and his staff in the DHS Office of Immigration Statistics and the staff of the Immigration Statistics Branch in the U.S. Census Bureau's Population Division. We are also grateful for assistance from Karl Eschbach, Linda Gage, Hans Johnson, Carolyn Liebler, Joe Salvo, Vicky Virgin, and several anonymous reviewers. All errors and omissions, however, are the responsibility of the authors.


We describe a method for producing annual estimates of the unauthorized immigrant population in the United Sates and components of population change, for each state and DC, for 1990–2010. We quantify a sharp drop in the number of unauthorized immigrants arriving since 2000, and we demonstrate the role of departures from the population (emigration, adjustment to legal status, removal by the Department of Homeland Security [DHS], and deaths) in reducing population growth from one million in 2000 to population losses in 2008 and 2009. The number arriving in the U.S. peaked at more than one million in 1999–2001 and then declined rapidly through 2009. We provide evidence that population growth stopped after 2007 primarily because entries declined and not because emigration increased during the economic crisis. Our estimates of the total unauthorized immigrant population in the U.S. and in the top ten states are comparable to those produced by DHS and the Pew Hispanic Center. However, our data and methods produce estimates with smaller ranges of sampling error.