Estimating the Unauthorized Immigrant Population and its

Geographic Distribution within Texas Counties

Miguel Flores, Lila Valencia, & Lloyd Potter

University of Texas at San Antonio

Applied Demography ConferenceJanuary 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

Background

1990 2000 2005 20080

200

400

600

800

1000

1200

1400

1600

1800

450

1,100

1,400 1,400

440

1,127

1,4741,527

1,090

1,360

1,680

Estimates of Texas Unauthorized Immigrant Popu-lation

(thousands)

Passel Warren DHS

Background

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 20100.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

5.0 5.4 5.3 5.5 6.1 6.9 6.9 7.7 7.5 6.9 6.9

2.32.7 2.8 2.8

2.92.7 2.9

2.8 2.72.6 2.61.1

1.2 1.3 1.41.4

1.5 1.51.5 1.4

1.6 1.7

Estimates of the Unauthorized Immigrant Popu-lation,

2000 to 2010

All Other States California Texas

Unauth

ori

zed I

mm

igra

nts

(in

millions)

Source: Pew Hispanic Center, 2011

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 200811.5

12.0

12.5

13.0

13.5

14.0

12.6

12.4 12.312.4

12.6

12.8

13.113.2 13.3 13.2

13.113.2

13.4 13.4 13.4 13.513.6

13.7 13.7

Estimates of Texas Unauthorized Immigrant Population as % of U.S. Total Unauthorized Immigrant Population

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 = Xtsα + Wtsβ + Ztsγ + εts

Final Model:

Methodology

2008

R squared 0.618

Coeff p-value

Born in Central America -0.5378 0.000

Filed taxes as married -0.48947 0.000

constant 0.598122 0.000

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 2008.

Methodology

county Total Returns ITIN filers % ITIN filers

Ochiltree 4,146 472 11.4Presidio 3,702 403 10.9

Titus 13,316 1,370 10.3Deaf Smith 7,860 799 10.2

Parmer 3,970 372 9.4Hansford 2,403 225 9.4Sherman 1,132 102 9.0

Dallas 1,017,378 84,841 8.3Gaines 6,100 501 8.2

Hemphill 1,650 135 8.2Texas (Total) 10,433,723 402,282 3.9

Top 10 counties with the highest % of ITIN filers, 2008

Rank County Estimates 2000 Rank County Estimates 2008

1 Harris 403,139 1 Harris 422,8652 Dallas 280,922 2 Dallas 322,0403 Tarrant 80,155 3 Tarrant 131,2964 Travis 51,829 4 Travis 82,2655 Collin 28,032 5 Collin 67,4676 El Paso 25,521 6 Bexar 49,4317 Bexar 24,088 7 Denton 39,6068 Hidalgo 22,632 8 Fort Bend 27,3329 Denton 20,108 9 El Paso 24,755

10 Fort Bend 19,754 10 Montgomery 22,881

Estimates of Texas Unauthorized Immigrant Population, Top 10 Counties

Total Population

(2008 ACS estimate) Estimates% of county total

population Harris 3,965,716 422,865 10.7 Dallas 2,387,963 322,040 13.5 Tarrant 1,740,964 131,296 7.5 Bexar 1,618,284 49,431 3.1 Travis 988,312 82,265 8.3 Collin 760,013 67,467 8.9 El Paso 748,596 24,755 3.3 Hidalgo 724,971 4,842 0.7 Denton 637,358 39,606 6.2 Fort Bend 533,696 27,332 5.1Texas (Total) 24,326,974 1,527,000 6.3

Unauthorized Population, 2008

Estimates of Unauthorized Immigrant Population in Texas, 2008 Top 10 most populated counties

County

Zip Code County Estimates75252 Collin 26,21075211 Dallas 20,01175217 Dallas 18,38375220 Dallas 14,53177081 Harris 12,78177036 Harris 12,18175061 Dallas 12,13976010 Tarrant 12,09075227 Dallas 11,53275228 Dallas 11,31177080 Harris 11,10375006 Dallas 10,64077084 Harris 10,47777093 Harris 10,41978753 Travis 10,36477449 Harris 10,00675042 Dallas 9,71376106 Tarrant 9,20577015 Harris 9,114

Estimates of Unauthorized Immigrant Population, 2008 Top 20 Zip Codes

Percentage of Total Population

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