The estimates in this report use a new data set that were provided by the Office of Immigration Statistics of the U.S. Department of Homeland Security to a group of researchers including Manuel Pastor of the University of Southern California (USC), David Ayon of Loyola Marymount University, Jonathan A. Fox of the University of California at Santa Cruz, Rob Paral and others. Information derived from the data set has recently been published by the Woodrow Wilson International Center for Scholars.
Staff at USC's Center for the Study of Immigrant Integration (CSII) processed the original OIS data into more usable shape and then refined the OIS data to account for emigration, mortality and derivative citizenship.
Funding for this effort was generously provided by the Carnegie Corporation of New York.
A complete data set of legal permanent residents by period of entry by naturalization status by 39 countries/world regions may be obtained from the Center for the Study of Immigrant Integration. Please contact Justin Scoggins at CSII.