Miguel Flores, Lila Valencia, & Lloyd Potter University of Texas at San Antonio Applied Demography Conference January 2012

  Conventionally, estimation of the unauthorized population is produced using the residual method (Warren 2011; Passel 2010, 2011)  Estimates of legal foreign born residents are subtracted from estimates of foreign born (either from the Current Population Survey (CPS) or the American Community Survey (ACS))  Most commonly used national and state estimates include Pew Hispanic Center, Dept. of Homeland Security, and Warren estimates Background

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 Source: Pew Hispanic Center, 2011

 Background Source: Warren, 2010

  Residual method produces some challenges when attempting to produce estimates at lower geographies  Hill & Johnson (2011) employ a methodology that combines census population data with new administrative data that allows for estimation of the total unauthorized population and its distribution at sub-state level geographies Background

  80 percent of unauthorized immigrants report filing federal income taxes and about 75 percent of unauthorized report having payroll taxes withheld (Porter 2005; Hill et al. 2010).  Since immigrants without work authorization do not have valid social security numbers, many instead use Internal Revenue Service (IRS) issued Individual Taxpayer Identification Numbers (ITIN) when filing tax returns.  Hill et al. (2011) have shown a high correlation between the ITIN filers and unauthorized immigrant estimates in the U.S. Literature Review

  ITINs data are available for tax years 2000 to 2008 at the zip code level.  Not all unauthorized immigrants file tax returns and not all ITIN filers are unauthorized (Hill et al. 2011).  To address this issue, we incorporate sociodemographic characteristics related to the unauthorized immigrant status from the ACS. Methodology

  The population is restricted to foreign-born residents (ITIN/Warren Estimate) ts = X ts α + W ts β + Z ts γ + ε ts  Final Model: Methodology 2008 R squared0.618 Coeffp-value Born in Central America Filed taxes as married constant

  The unauthorized estimates were totaled and scaled to match Warren’s estimate of unauthorized for the state.  These estimates are then used to generate counts of the unauthorized population at the sub-state level.  Estimates of the unauthorized population are produced for county and zip code for the state of Texas.  The analysis is replicated for several years, 2000, 2005 and Methodology

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 Percentage of Total Population

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  Preliminary county and zip code level estimates appear to be in line with:  Agricultural areas  Urban areas  Areas of high employment  Areas experiencing Hispanic population growth  Areas with substantial foreign born population  These areas include counties and zip codes in the Dallas-Fort Worth-Arlington, Houston-Baytown-Sugarland, and Austin-Round Rock metropolitan areas, large border counties, and counties in parts of East Texas. Results

  Estimate model specific to Texas  Explore trends from available data Future Directions