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Estimates of the Legal Permanent Resident Population in 2008

Estimates of the Legal Permanent Resident Population in 2008

This report presents estimates of the legal permanent resident (LPR) population living in the United States on January 1, 2008. The LPR population includes persons granted lawful permanent residence, for example, “green card” recipients, but not those who had become U.S. citizens. The estimates are shown for the total LPR population and the LPR population eligible to apply to naturalize by country of birth, state of residence, and the year LPR status was obtained. Data for the estimates were obtained primarily from administrative records of U.S. Citizenship and Immigration Services (USCIS) of the Department of Homeland Security (DHS). The methodology used for the 2007 estimates is similar to that used in previous DHS estimates (see Rytina, 2008 and 2009).

In summary, an estimated 12.6 million LPRs lived in the United States on January 1, 2008. One-half obtained LPR status in 2000 or later; one-quarter became LPRs during 2005-2007.


Data on the size and characteristics of the foreign-born population are needed to assess the impact of immigration and integration of immigrants into U.S. society. The decennial census and monthly household surveys of the Census Bureau include questions on place of birth, citizenship, and year of entry into the United States. These data provide a wealth of information on the total foreign-born population, naturalized citizens, and non-citizens. However, national population data on the major subcategories of non-citizens, including LPRs, students, temporary workers, and unauthorized immigrants, are not readily available from any source and must be estimated. An alien registration program requiring all legally resident aliens to report their status annually to the legacy Immigration and Naturalization Service was discontinued by Congress in 1981. Immigration data collected by DHS measure administrative events such as the number of aliens granted lawful permanent residence or the number approved for asylum, but not the population of legal permanent residents or the population of asylees living in the United States at a point in time. Estimates of the LPR population have been derived primarily from Census and DHS data by estimating a base population as of a certain date and adding subsequent components of population change (see Passel and Clark, 1998; Hoefer, 1996). A variant of this approach has been used by DHS since 2002 to estimate the resident LPR population.


Separate population estimates were developed for LPRs who entered the United States before 1980 and during the 1980-2007 period. The two sets of estimates were added together to obtain the overall estimated population as of January 1, 2008.

Estimates for LPR Entrants Prior to 1980

It was assumed that all non-citizen residents of the United States in 2008 who entered before 1980 were legal permanent residents. Under the registry provisions of immigration law, aliens of good moral character who are not ineligible to naturalize, are not removable on terrorism grounds and have lived in the United States continuously since January 1, 1972 are eligible for LPR status. Additionally, certain persons living in the United States before 1982 as unauthorized residents were permitted to adjust to LPR status under the provisions of the Immigration Reform and Control Act of 1986. DHS estimates of the unauthorized immigrant population, using the same rationale, assume that the foreign-born population entering the United States before 1980 is legally resident (see Hoefer, Rytina, and Baker, 2009). Estimates of the LPR population in 2008 that entered before 1980 were obtained from data from the 2007 American Community Survey (ACS) of the U.S. Census Bureau on non-citizen residents with a year of entry prior to 1980. The ACS data were tabulated by year of entry (assumed to be the year that LPR status was obtained), country of birth, and state of residence.

Estimates for LPR Entrants from 1980 through 2007

Data on LPRs who entered the United States between January 1980 and December 2007 were obtained from application case tracking systems of USCIS. Information on persons obtaining LPR status is supplied on two applications. The Application for Immigrant Visa and Alien Registration (DS-230) of the U.S. Department of State is used by aliens living outside the United States. DS-230 applicants who subsequently become LPRs are known as “new arrivals.” The Application to Adjust Status to Permanent Residence (I-485) is used by aliens already living in the United States. I-485 applicants who become LPRs are referred to as “adjustments of status.” Information on the naturalization of LPRs comes from the Application for Naturalization (N-400). The N-400 application is used by persons aged 18 years and over. Basic applicant informa tion maintained in the case tracking systems includes alien identification number (A-number), date of birth, country of birth, gender, U.S. address, date LPR status or naturalization was obtained, and category of admission for LPR status.

Records for LPR entrants from January 1980 through December 2007 were matched by A-number with naturalization records for the same time period in order to exclude LPRs who subsequently naturalized. Several adjustments were then made to reduce the aggregated total of 1980-2007 LPRs to a 2008 LPR population of 1980-2007 entrants. The adjustments for emigration and mortal ity are methodologically the same as those used in DHS unauthorized immigrant population estimates. An adjustment for derivative citizenship is unique to the LPR population estimates.

LPRs who entered the United States before 1980 were excluded as these persons were counted in the pre-1980 entrant population from the ACS. The date of entry for “new arrival” LPRs is the date of approval for LPR status. For “adjustment of status” LPRs, how ever, the entry date is usually not recorded directly so the year of last entry prior to adjustment of status was selected as an approxi mation. Year of last entry was imputed where missing (approximately 40 percent of adjustment of status records during 1998-2005) using category of admission, year of LPR adjustment, and known last entry date. Additional adjustments, described below, were made for LPR children who had derived citizenship, mortality, and emigration.

Derivative Citizenship. Most LPRs become U.S. citizens by applying for naturalization (using the N-400 form) when they are at least 18 years old. Some LPRs, however, become U.S. citizens by deriving cit izenship upon the naturalization of a parent and may, but are not required to, apply for a certificate of citizenship (using Form N-600). The number of LPRs deriving citizenship was estimated from appli cations filed for certificate of citizenship from 1980 through 2007. This approach, like its predecessor , produces a conservative esti mate of derivative citizenship but was adopted because it is straightforward and produces a slightly larger and presumably more accurate estimate for recent years. The impact on the LPR population estimate for 2006-2008 is small—a 2-3 percent reduction.

Mortality. LPRs were survived to 2008 by age (when LPR status was obtained) and gender using mortality rates by age and sex from 1989-91 life tables (National Center for Health Statistics, 1997). The median age of foreign nationals at the time they become LPRs is about 32 years (Monger and Rytina, 2009). As a result, mortal ity has very little impact on the estimates for recent LPRs but a greater impact for those who became LPRs during the 1980s.

Emigration. Most observers agree that a sizable number of LPRs emi grate from the United States. The U.S. government has not collected official statistics since 1957. National data that directly measure emigration do not exist. This report uses an average annual rate of emigration of approximately 1 percent based on estimates for the foreign-born population from Census data (Ahmed and Robinson, 1994). The rates vary by years of residence in the United States and naturalization status. (LPRs who subse quently naturalized were not considered at risk of emigration until after becoming citizens). LPRs who entered the United States as asylees and refugees were assumed not to emigrate.

After adjusting for derivative citizenship, mortality, and emigra tion, estimates for 1980-2007 entrants were tabulated by the year LPR status was obtained, country of birth, and state of residence. The use of state of residence provided on the application for per manent residence ignores subsequent internal migration and affects the state-level estimates to

LPR Population Eligible to Naturalize

LPRs are eligible to apply for naturalization after meeting U.S. residency and other requirements. This report estimates the LPR population eligible to naturalize based on residence require ments using class of admission and the year LPR status was obtained. Most LPRs are required to meet a five-year residency requirement for naturalization. Spouses of U.S. citizens are eligi ble to apply in three years. There are several other exceptions to the five-year residency requirement, most of which affect small numbers of immigrants.

It was assumed that all LPRs are required to meet a five-year resi dency requirement except for those whose permanent resident status was as a spouse of a U.S. citizen. Certain categories of immi grants receive credit for the period prior to the actual grant of lawful permanent resident status. The credited time or earlier dates are not included in the LPR records used for this analysis and must be estimated. Asylees are credited one year in asylum status toward lawful permanent resident status. Asylees were therefore assumed eligible to naturalize four years after approval of the adjustment of status application.

Immigrants adjusting to LPR status as refugees, Lautenberg parol ees, or through cancellation of removal also receive credit for residence in the United States prior to the actual grant of lawful permanent residence based, respectively, on the date of entry into the United States as a refugee, the date of parole, and the date of cancellation of removal. It was assumed that two years elapse between the earlier dates and the date of approval of the applica tion for permanent residence so that these LPRs are eligible to apply for naturalization approximately three years after approval of their application for adjustment.