United States General Accounting Office 

Report to the Chairman, Committee 

on the Judiciary, House of 

Representatives 

GAO

June 2004 ILLEGAL ALIEN 

SCHOOLCHILDREN 

Issues in Estimating 

State-by-State Costs

GAO-04-733 
www.gao.gov/cgi-bin/getrpt?GAO-04-733.

To view the full product, including the scope 

and methodology, click on the link above. 

For more information, contact Nancy 

Kingsbury at (202) 512-2700 or 

kingsburyn@gao.gov. 

Highlights of GAO-04-733, a report to the 

Chairman of the Committee on the 

Judiciary, House of Representatives 

June 2004

ILLEGAL ALIEN SCHOOLCHILDREN

Issues in Estimating State-by-State Costs 

Current government information is not sufficient to directly estimate the stateby-state costs of educating illegal alien schoolchildren. Although a variety of 

data are available, no government source estimates the numbers of illegal alien 

schoolchildren for most or all states. Specifically: 

• States and local areas record data on school enrollment and costs but not 

on immigration status. In response to GAO’s survey, a few states estimated 

costs of educating illegal alien children, based partly on assumptions. 

• The National Center for Education Statistics (NCES) maintains enrollment 

and cost data—but has no information on immigration status. 

• The Department of Homeland Security (DHS) developed state-by-state 

estimates of the illegal alien population, but the estimates do not break out 

age groups and are subject to methodological limitations. 

The Census Bureau is developing a plan to estimate the size of the resident 

illegal alien population, indirectly by age group and state. This new 

information might help in developing state-by-state estimates of the number of 

school-age illegal alien children. However, the plan does not specify the age 

groups to be estimated, faces technical challenges, and depends upon future 

funding. Overall, it is too early to evaluate the Census Bureau’s plan. 

The simplest approach to estimating the costs of educating illegal alien 

children is to multiply average current per pupil expenditures by the estimated 

number of illegal alien schoolchildren separately for each state (see fig.). At 

present, government information is insufficient for developing reliable 

estimates based on this approach. If the Census Bureau’s plan proves 

successful, relevant data would be available by 2007–09. Taking account of 

cost determinants such as variation in local area expenditures, student needs, 

and school capacity requires additional data. 

Simplest Approach to State-by-State Cost Estimation 

Sources: GAO (analysis), NCES (per pupil expenditure data), Census Bureau (estimation plans), U.S. Department of Education (photo).

Each state's average

per pupil expenditures

Data currently available 

from National Center 

for Education Statistics

Estimated number of 

illegal alien schoolchildren 

in each state

Each state's cost of 

educating illegal alien 

schoolchildren

No government 

estimate; by 2007-09, 

Census may estimate 

illegal aliens by age

Reliable estimates 

based on government 

data are not currently 

possible

In 1982 the Supreme Court ruled 

that states and school districts 

cannot deny education to illegal 

alien children residing here. Issues 

in estimating the costs of providing 

education to them are of interest 

because (1) policy discussions 

concerning illegal immigration 

often focus on cost impacts; (2) 

potential costs are borne mostly at 

the state and local levels; and (3) 

the Congress could authorize 

federal reimbursement for benefits 

provided to illegal aliens, based on 

estimated state costs or numbers of

illegal aliens. 

The foreign-born population is 

growing and is concentrated in 

certain states; the illegal immigrant 

component is thought to be 

substantial. Concerns about 

education costs may reflect 

“squeezed” state and local budgets, 

rising school enrollments, and 

overcrowded schools. 

To address the potential for 

estimating the costs of educating 

illegal alien schoolchildren, this 

report (1) identifies major 

government sources of relevant 

data, (2) describes a Census 

Bureau plan for developing new 

information, and (3) outlines costestimation approaches. 

GAO provided a draft of this report 

to the National Center for 

Education Statistics, the 

Department of Homeland Security, 

and the Census Bureau. The 

agencies informed GAO they had 

no formal comments. 
Page i GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

Letter 1

Results in Brief 2

Background 3

Objectives, Scope, and Methodology 10

Currently Available Government Information 12

The Census Bureau’s Plans for Estimating Illegal Immigrants Are 

Preliminary 18

Approaches to Cost Estimation 21

Observations 28

Agency Comments 28

Table 

Table 1: Cost Categories Relevant to the School-Capacity Approach 27

Figures 

Figure 1: Total Foreign-Born Population (Legal and Illegal) in Key 

States, 1990 and 2000 7

Figure 2: Simplest State-by-State Estimation Approach 22

Abbreviations

ACS American Community Survey 

CPS Current Population Survey 

DHS Department of Homeland Security 

ELL English language learner 

INS Immigration and Naturalization Service 

NCES National Center for Education Statistics 

TPS temporary protected status 

Contents 

This is a work of the U.S. government and is not subject to copyright protection in the 

United States. It may be reproduced and distributed in its entirety without further 

permission from GAO. However, because this work may contain copyrighted images or 

other material, permission from the copyright holder may be necessary if you wish to 

reproduce this material separately. 
Page 1 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

June 21, 2004 

The Honorable F. James Sensenbrenner, Jr. 

Chairman 

Committee on the Judiciary 

House of Representatives 

Dear Mr. Chairman: 

Reliable data are needed to support policy decisions in the area of illegal 

immigration, but such data have often been lacking or inadequate.1

 In this 

report, we respond to your request that we examine the potential for 

estimating state-by-state costs of public schooling for illegal alien children, 

based on government information.2

As you know, the U.S. Supreme Court has ruled that states and school 

districts cannot deny K-12 education to resident children who are illegal 

aliens. Government estimates of the state-by-state costs of educating them 

would, however, be policy relevant for a number of reasons, such as the 

potential for federal reimbursement to states. 

Because government estimates are not available at present, in this report 

we (1) identify currently available government information, (2) describe 

the Census Bureau’s plan for developing new information, and (3) outline 

possible approaches to estimating costs and, for each approach, briefly 

assess whether needed information is currently available or planned. 

GAO collected relevant information through a survey of 20 states, did 

outreach through associations of governors and mayors, conducted 

 1

See U.S. Commission on Immigration Reform, Becoming an American: Immigration and 

Immigrant Policy (Washington, D.C.: Government Printing Office, 1997), pp. 194-98. We 

pointed to this issue in U.S. General Accounting Office, Immigration Statistics: 

Information Gaps, Quality Issues Limit Utility of Federal Data to Policymakers, 

GAO/GGD-98-164 (Washington, D.C., July 31, 1998), pp. 12–13 and 22–24. 

2

According to data from the National Center for Education Statistics (NCES), the 

proportion of students in private elementary and secondary schools has changed little over 

the past 10 years, remaining around 11 percent; we do not include or discuss expenditures 

by private schools in this report. 

United States General Accounting Office 

Washington, DC 20548 
Page 2 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

interviews at federal agencies, performed a literature review, and 

consulted with experts. 

Overall, our review indicates that at present, government information is 

not sufficient for directly estimating the state-by-state costs of providing 

public schooling to illegal alien children. Specifically: 

• Government data include a variety of information on school 

expenditures and on the foreign-born population. However, estimates 

of the numbers of illegal alien schoolchildren, by state, are lacking. 

• The Census Bureau has outlined a preliminary plan to develop indirect 

state-by-state estimates of the resident illegal alien population by age. 

Such estimates could help determine the number of schoolchildren in 

that population. But even if age-group estimates are successfully 

developed, they would not be available before 2007–09. 

• Approaches to state-by-state cost estimation differ in the extent to 

which they attempt to account for various factors that can affect costs, 

but all approaches require data on or estimates of the number of illegal 

alien schoolchildren in each state. 

State governments and school districts routinely record school 

enrollments and dollar expenditures. Although a few states responded to 

our survey with estimates of the costs of educating illegal alien children, 

none actually collect data on children’s immigration status. 

At the federal level, the National Center for Education Statistics (NCES) 

centrally maintains data on school enrollment and expenditures, as well as 

certain other information. (For example, NCES has collected data on 

school overcrowding for a sample of areas.) But like the states and school 

districts, NCES has no data on the immigration status of schoolchildren. 

The Census Bureau collects citizenship data on foreign-born U.S. 

residents, including children, but does not ask further questions about 

immigration status. 

The Department of Homeland Security (DHS) has developed indirect stateby-state estimates of the size of the resident illegal population, but these 

Results in Brief 
Page 3 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

estimates do not break out age groups; the DHS estimates are subject to 

methodological limitations as well.3

The Census Bureau has outlined a plan for research to develop age-group 

estimates for the resident illegal immigrant population, by geographic 

divisions (states and selected counties), with trends across time. It is too 

early to judge the quality of this plan, but if it is successfully implemented, 

it could help quantify the school-age portion of the resident illegal alien 

population. The Census Bureau also suggested that other government 

agencies might expand on its planned population estimates—for example, 

by developing further estimates on the extent to which illegal alien 

children attend public schools or require special programs. 

The simplest approach to estimating state-by-state costs multiplies current 

average per pupil expenditures for each state by an estimate of the number 

of illegal alien children attending school in that state. Other approaches 

take account of potentially key cost factors, including cost variations 

across local areas within a state and higher costs for students needing 

special programs, such as English Language Learner (ELL) programs.4

 Yet 

another approach assesses the role of enrollment growth, school capacity, 

and “incremental costs.”5

 All these approaches require estimates of 

numbers of illegal alien schoolchildren by state. 

We provided a draft of this report to the Census Bureau, DHS, and NCES. 

The agencies informed us that they had no formal comments, but we 

received informal comments from the Census Bureau and NCES on minor 

technical points and made changes in the report as appropriate. 

In 1982, the U.S. Supreme Court ruled that it would be unconstitutional for 

any state or school district to deny K-12 education to a child residing in 

that state or school district on the basis of the child’s being an illegal 

 3

DHS estimates use decennial census data on the foreign-born population and 

administrative data on legal immigrants, among other sources. These estimates are termed 

“indirect” because information on the illegal immigrant population is not directly collected; 

instead, a variety of other estimates (some marked by uncertainty) are combined to project 

state-by-state figures for this population. 

4

The term English language learner is defined in the Background section of this report (see 

p. 10). 

5

Theoretically, in schools or classes with excess capacity, enrollment growth might not 

cause overcrowding, and incremental per pupil costs might be lower than average per pupil 

costs. Otherwise, the opposite would hold true. 

Background 
Page 4 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

alien.6 Nevertheless, issues in estimating the state-by-state costs of 

educating illegal alien children are policy relevant because 

1. concern about cost impacts is often among the issues raised in debates 

and discussions about immigration policy,7

2. illegal alien schoolchildren represent a potential cost component that 

is particularly relevant to states and local areas because they bear 

most of the costs of educating illegal alien schoolchildren,8

 and 

3. the Congress could authorize federal reimbursement of the costs of 

providing K-12 education to illegal alien children, based on the stateby-state costs of educating them or on the estimated numbers residing 

in each state.9

The following sections provide background on (1) issues that have 

heightened concern about the costs of educating illegal alien 

schoolchildren; (2) variation in education expenditures—and immigration 

levels—across states and local areas; and (3) other factors that may 

contribute to cost variation. 

Concern about the costs of illegal alien schoolchildren may be heightened 

because education costs are high and the illegal immigrant population is 

thought to be large. 

According to NCES, for the 1999–2000 school year, current expenditures 

by primary and secondary public schools—not including capital outlays—

 6

See Plyler v. Doe, 457 U.S. 202 (1982). 

7

U.S. Commission on Immigration Reform, U.S. Immigration Policy: Restoring 

Credibility. (Washington, D.C.: Government Printing Office, 1994), pp. 109–43. 

8

U.S. Commission on Immigration Reform, U.S. Immigration Policy: Restoring 

Credibility, pp. 143–52. 

9

Such reimbursement was recently enacted for emergency health benefits. The Medicare 

Prescription Drug, Improvement, and Modernization Act of 2003, Public Law 108-173 (Dec. 

8, 2003), §1011, Federal Reimbursement of Emergency Health Services Furnished to 

Undocumented Aliens, specifies that annually, from 2005 through 2008, $167 million will be 

distributed among the states, based on the estimated percentage of undocumented aliens 

residing in each state. Also see U.S. General Accounting Office, Undocumented Aliens: 

Questions Persist about Their Impact on Hospitals’ Uncompensated Care Costs. 

GAO-04-472 (Washington, D.C.: May 21, 2004). 

Concern about Costs May 

Be Heightened 
Page 5 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

totaled about $324 billion. Capital outlays in that school year—for facilities 

acquisition and construction—were an additional $35 billion.10 These costs 

were borne primarily at state and local levels; federal dollars represented 

about 7 percent of school revenue.11

The Immigration and Naturalization Service (INS) estimated that the 

illegal immigrant population increased to 7 million as of January 2000.12

However, there is no government estimate of the percentage of the illegal 

alien population that is of school age or that is now attending public 

school in grades K-12. 

Some possibly related reasons for concern about costs include the 

following: 

• Many state and local budgets are squeezed, and education costs 

represent their largest expenditure item.13

 10An additional $22 billion was spent on other categories and programs, some not part of K12 education. “Current expenditures,” as used in the NCES finance surveys, means current 

expenditures for public elementary and secondary education—not including capital 

outlays. Current expenditures include instruction expenditures and expenditures for other 

functions that support public elementary and secondary education, such as school support 

(guidance counselors, nurses), instructional support (libraries, teacher training), 

administration, student transportation, and food services. School districts also spend 

money on functions that fall outside of public elementary and secondary education, such as 

adult education, community services, and support for private education. NCES collects 

and tracks these expenditures separately. 

11Local dollars represented 43 percent of total school revenues and state dollars 50 percent. 

National Center for Education Statistics, Statistics in Brief (Washington, D.C.: May 2002), 

p. 1. More recently, the No Child Left Behind Act of 2001 (Public Law 107-110, Jan. 8, 2002) 

may have increased the federal share slightly, at least in some states. Notably, title III 

specifies a formula grant program, based on estimated state-by-state distributions of 

children who have limited English proficiency and are recent immigrants. 

12U.S. Immigration and Naturalization Service, Office of Policy and Planning, “Estimates of 

the Unauthorized Immigrant Population Residing in the United States: 1990-2000,”

Washington, D.C., January 2003. (On March 1, 2003, INS was transferred from the 

Department of Justice to DHS.) We discuss the 7 million estimate in a later section of this 

report; for a fuller discussion, see U.S. General Accounting Office, Overstay Tracking: A 

Key Component of Homeland Security and a Layered Defense, GAO-04-82 (Washington, 

D.C.: May 21, 2004), app. III. 

13See Elizabeth McNichol and Makeda Harris (“Many States Cut Budgets as Fiscal Squeeze 

Continues,” Center on Budget and Policy Priorities, Washington, D.C., 2004), who state that 

“the amount of state education spending included in proposed fiscal year 2005 budgets in a 

number of states—including California . . . [and] New York . . . falls short of the amount 

needed to maintain current-law funding levels or restore cuts made over the last few 

years.” 
Page 6 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

• School enrollments are rising. From 1990 to 2000, school enrollments 

rose about 15 percent—with steeper rises in states like Nevada (with 

an increase close to 70 percent), Arizona and Florida (each with an 

increase greater than 30 percent), and California, Colorado, and 

Georgia (each with an increase of about 25 percent). 

• Despite a 1990s boom in school construction, one in five schools were 

overcrowded in 1999, rising to one in three for schools in western 

states.14

It is likely that the costs of educating illegal alien children vary across 

states and local areas because (1) immigration (including foreign-born 

persons residing here legally and illegally) is heavily concentrated in 

certain areas and (2) per pupil school expenditures vary by state and 

school district. 

As shown in figure 1, between 1990 and 2000 foreign-born populations 

increased in the top 5 traditional destination states—California, Florida, 

Illinois, New York, and Texas. As of 2000, the foreign-born represented 12 

to 26 percent of these states’ populations. (Illegal immigration may follow 

similar patterns; for example, INS estimated that as of January 2000, 2 

million illegal immigrants resided in California, 1 million in Texas, and 

nearly 1⁄2 million in New York.) Also, as illustrated in figure 1, certain 

smaller states (with somewhat lower concentrations of immigrants—for 

example, Georgia, Nevada, and North Carolina have 5 to 16 percent 

foreign born) have recently experienced growth in their foreign-born 

populations. 

 14U.S. General Accounting Office, School Facilities: Construction Expenditures Have 

Grown Significantly in Recent Years, GAO/HEHS-00-41 (Washington, D.C.: Mar. 3, 2000), 

p. 7, and National Center for Education Statistics, The Condition of Education 2001: 

Indicator 45, Overcrowding in Schools, NCES-2001-072 (Washington, D.C.: U.S. 

Government Printing Office, 2001), p. 72. NCES defined overcrowding as enrollment more 

than 5 percent above the facility’s initial capacity. About half of all schools were operating 

at less than capacity. 

Immigration Levels and 

Education Costs Vary 

across Areas 
Page 7 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

Figure 1: Total Foreign-Born Population (Legal and Illegal) in Key States, 1990 and 2000 

Note: Data or estimates for illegal aliens are not available from the Census Bureau. Other state-bystate estimates of illegal aliens are not included because of data reliability concerns. 

States with at least 10 percent foreign born as of 2000 that are not shown 

in figure 1 include Arizona, Hawaii, New Jersey, and Rhode Island. In 

contrast, states such as Mississippi, Montana, North Dakota, South 

Dakota, and West Virginia had 2 percent or less foreign born. 

Per pupil school expenditures also vary by state. To illustrate this for 

selected states, in the 1999–2000 school year, current per pupil 

expenditures (exclusive of capital outlays) averaged about 

• $10,000 in New York and New Jersey 

• $8,000 in Michigan and Wisconsin 

0

1

2

3

4

5

6

7

8

9

Million

Calif. N.Y. Tex. Fla. Ill. Ga. Nev. Ark. N.C. Utah

Traditional destination states of foreign-born population States with highest percentage of growth in foreign-born population

Source: Census Bureau.

1990 foreign-born population

2000 foreign-born population
Page 8 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

• $7,000 in Illinois, Indiana, and Virginia 

• $6,000 in California, Florida, Georgia, Nevada, and North Carolina 

• $5,000 in Arizona and Arkansas 

• $4,000 in Utah15

Local areas can also vary in terms of both immigration concentration and 

per pupil expenditures, despite equalization rules and programs in some 

states.16 

Two California areas serve as illustration.17 Current per pupil expenditures 

in Pasadena Unified School District (near Los Angeles) averaged about 

$7,000 for the 1999–2000 school year; about 24 percent of the population in 

Pasadena City is foreign born. In contrast, current per pupil expenditures 

in Fairfield-Suisun School District averaged about $5,000; this school 

district is the largest in Solano County (located between San Francisco 

and Sacramento), in which about 17 percent of residents are foreign-born. 

A variety of factors affect local-area costs. For example, among other 

determinants, teacher salaries may vary according to the cost of living in 

different areas of a state. 

Other factors that add to the complexity of fully accounting for variation 

in education costs include variation in student needs and school capacity. 

Even within a single school district, costs can vary among individual 

students. That is, expenditures are higher for students who live in poverty 

 15Table 167, Total and Current Expenditures Per Pupil in Fall Enrollment in Public and 

Secondary Public Education, by Function and State: 1999-2000. NCES Digest of Education 

Statistics, List of Tables and Figures for 2002, ch. 2, Elementary and Secondary Education, 

Revenues and Expenditures. http://www.nces.ed.gov/programs/digest/ (May 16, 2004). 

Note: Excludes capital expenditures. We report costs for the 1999–2000 school year for 

consistency with decennial census data. The most recent cost data available from NCES 

indicate that by 2001–02, per pupil expenditures had increased by an average of $765 for 

these states as a group. 

16In 1971, the California Supreme Court ruled in Serrano v. Priest, 487 P.2d 1241 (Cal. 

1971), that equalization of revenue should be required across school districts. Various other 

states also have equalization programs. For a summary of “persistent challenges” to fiscal 

equity or adequacy, and a list of relevant studies, see Margaret Hadderman, “Equity and 

Adequacy in Educational Finance.” ERIC Digest. http://www.ericdigests.org/2002-

1/equity.html (May 19, 2004). 

17Table 91, Revenues and Expenditures of Public School Districts Enrolling More Than 

15,000 Pupils, by State: 1999-2000. NCES Digest of Education Statistics, List of Tables and 

Figures for 2002, ch. 2, Elementary and Secondary Education, Schools and School Districts. 

http://www.nces.ed.gov/programs/digest/ (May 17, 2004). 

Other Factors Are Related 

to Costs 
Page 9 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

or who have limited English proficiency, if schools attempt to meet these 

needs (for example, with English Language Learner or ELL programs). 

According to the Education Alliance at Brown University, ELL indicates 

a person who is in the process of acquiring English and has a first language other than 

English. Other terms commonly found in the literature include language minority students, 

limited English proficiency (LEP), English as a second language (ESL) and culturally and 

linguistically diverse (CLD).18

In 2000–2001, some school districts enrolled high percentages of students 

in various ELL programs. More than 40 percent of Los Angeles students 

and about 33 percent of Dallas students are enrolled in ELL programs; of 

course, not all students enrolled in these programs are foreign-born.19 

The costs of meeting the needs of such students have been variously 

estimated. Bringing ELL-enrolled children up to the grade level of sameage non-ELL-enrolled children has been estimated to potentially increase 

costs by an additional 10 to 100 percent over usual per pupil costs; for 

students living in poverty (independent of ELL programs), the 

corresponding range of estimates is 20 to 100 percent.20 Bringing students 

 18See the Education Alliance at Brown University, http://www.lab.brown.edu/tdl/ell.shtml

(May 20, 2004). NCES describes ELL students as “born outside of the United States with a 

native language other than English; or . . . from environments where the language is 

predominantly non-English; or . . . American Indians and Alaska Natives whose level of 

English proficiency may have been affected by a non-English environment resulting in 

difficulty speaking, reading, writing, or understanding the English language.” NCES notes 

that ELL students were “formerly known as Limited-English-Proficient (LEP).” See 

National Center for Education Statistics, Instructions for Completing the Nonfiscal 

Surveys of the Common Core of Data: School Universe Survey, Agency Use Survey, State 

Nonfiscal Survey, 2003-2004 (Washington, D.C.: U.S. Department of Education, OMB No. 

1850–0067, expires Nov. 30, 2004), p. 94. 

19See Beth Antunez, English Language Learners in the Great City Schools: Survey Results 

on Students, Languages, and Programs (Washington, D.C.: Council of Great City Schools, 

March 2003). 

20See U.S. General Accounting Office, School Finance: Per-Pupil Spending Differences 

between Selected Inner City and Suburban Schools Varied by Metropolitan Area, 

GAO-03-234 (Washington, D.C.: Dec. 9, 2002), pp. 5-6; William Duncombe, Anna Lukemeyer, 

and John Yinger, “Financing an Adequate Education: A Case Study of New York,” in 

William J. Fowler, ed., Developments in School Finance: 2001-02 (Washington, D.C.: 

National Center for Education Statistics, 2003); and U.S. General Accounting Office, 

Bureau of Indian Affairs Schools: Expenditures in Selected Schools Are Comparable to 

Similar Public Schools, but Data Are Insufficient to Judge Adequacy of Funding and 

Formulas, GAO-03-955 (Washington, D.C.: Sept. 4, 2003), p. 39. 
Page 10 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

characterized by both poverty and limited English proficiency up to 

average levels of achievement could potentially increase average costs by 

a larger amount—perhaps 30 to 200 percent over average per pupil costs. 

School capacity to absorb new students is an issue because some schools 

are overcrowded while others are operating below capacity. This suggests 

variation across schools in the added costs associated with enrolling 

additional children, such as illegal alien children. 

Finally, we note that a broad array of costs additional to dollar costs may 

potentially be relevant. For example, overcrowded facilities may be 

related to growth in enrollments and, thus, to immigration. If sufficient 

temporary space is not added, class-size—and, potentially, the quality of 

education—may be affected.21

Our objectives were to address three questions regarding the potential for 

estimating the costs of educating illegal alien schoolchildren K-12, by state, 

using government information: 

1. What information is currently available from state and local 

governments or federal agencies on either the specific costs of 

educating illegal alien schoolchildren or related topics, such as overall 

education costs or the illegal alien population? 

2. What is the Census Bureau’s plan for developing new information on 

the illegal alien population in the future? 

3. What are possible approaches to estimating the costs of educating 

illegal alien schoolchildren, and are government data available to 

support such approaches? 

The main methods we used to address these questions included: 

• A mail survey sent to 22 states, which we selected to include (1) the 

major immigration-destination states, identified in terms of numbers of 

 21See Ricardo R. Fernandez and P. Michael Timpane, “Bursting at the Seams: Report of the 

Citizens’ Commission on Planning for Enrollment Growth,” Office of the Chancellor, Board 

of Education, New York City, 1995, and Francisco Rivera-Batiz and Lillian Marti, “A School 

System at Risk: A Study of the Consequences of Overcrowding in New York City Public 

Schools,” Institute for Urban and Minority Education, Teachers College, Columbia 

University, New York, New York, 1995. 

Objectives, Scope, 

and Methodology 
Page 11 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

foreign-born residents; (2) the main new-growth states, which we 

identified on the basis of large percentage increases in numbers of 

foreign-born residents; and (3) some other states with lower 

percentages of foreign-born residents (questions 1 and 3).22 

• Telephone or e-mail inquiries to six local government or school district 

officials (question 1).23

• Outreach to states and local areas through the National Governors 

Association and the U.S. Conference of Mayors (question 1). 

• Discussions with officials and staff at NCES, DHS (which incorporates 

the former INS), and the Census Bureau, plus a collection of relevant 

documents from these agencies (questions 1 and 2).24

• Analysis, including a review of literature and of the results from our 

state survey, local area checks, and discussions with federal agencies—

as well as consultation with experts in economics and school funding 

(question 3).25

In discussions with your staff, we agreed to limit the scope of this report 

to (1) government estimates and government sources of information, (2) 

children of illegal aliens born outside the United States, and (3) issues 

concerning the estimation of gross costs, rather than attempting to 

 22We asked for specific information on enrollments of illegal alien schoolchildren, the costs 

of educating these children, and opinions on the factors that should be considered in 

estimating these costs. The 20 states that responded were Arizona, Arkansas, California, 

Colorado, Illinois, Indiana, Iowa, Kentucky, Michigan, Nebraska, Nevada, New Jersey, New 

York, North Carolina, Pennsylvania, Tennessee, Texas, Utah, Virginia, and Wisconsin. The 2 

that did not respond were Florida and Georgia. We supplemented our mailing to the 22 

states with e-mails, faxes, and telephone calls. 

23We contacted local officials in (1) two traditional destinations for immigrants (Los 

Angeles County, California, and New York City), (2) the fastest growing urban area in the 

United States (Las Vegas, Nevada), (3) two suburban counties (Arlington, Virginia, and 

Fairfax, Virginia), and (4) one city on the Mexico-United States border (Nogales, Arizona). 

24Other than NCES, DHS, and the Census Bureau, we could not identify any federal agency 

as a primary source of information on illegal alien schoolchildren, whether numbers or 

costs. 

25These include F. Howard Nelson of the American Federation of Teachers Educational 

Foundation; Frank H. Johnson, an NCES statistician; and GAO’s Chief Economist as well as 

GAO’s Center for Economics staff. 
Page 12 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

quantify net impacts.26 Additionally, we did not consider preschool, 

postsecondary, or after-school programs. 

With respect to data reliability, we discussed NCES data quality 

procedures with an NCES statistician specializing in NCES surveys of 

school expenditures and enrollments, and we reviewed NCES’s survey 

documentation. We determined that the NCES data were sufficiently 

reliable for use in estimating school costs.27 As we discuss in the body of 

the report, other federal information concerning estimates of illegal aliens 

is not as reliable.

We conducted our work in accordance with generally accepted 

government auditing standards from January 2003 to May 2004. 

Looking across local, state, and federal levels of government, we found 

that a wealth of data are available on school enrollments and dollar 

expenditures, but with few exceptions, specific information on illegal alien 

schoolchildren has not been developed. 

Of the 22 state governments we surveyed, only 3 provided information on 

the costs of schooling illegal alien children. Seventeen states said that 

they did not have such information, and 2 states (Florida and Georgia) did 

not respond. 

Texas, Pennsylvania and North Carolina multiplied their states’ average 

current per pupil expenditures for the 1999–2000 school year by estimates 

of the number of illegal alien schoolchildren. Specifically: 

 26We excluded from consideration the costs of educating children born in the United States 

(and, therefore, U.S. citizens) to parents who were illegal immigrants. Net costs of 

providing benefits to a specific population would consider the full range of benefits 

received by that population as well as taxes paid and other potential contributions. 

Because we are not examining net costs, we do not address the issue of life-cycle analysis. 

Barry Edmonston and Ronald Lee, eds., discuss life-cycle analysis briefly in Local Fiscal 

Effects of Illegal Immigration: Report of a Workshop (Washington, D.C.: National 

Academy Press, 1996), p. 25. 

27NCES data do not break out certain costs that are needed for some approaches to cost 

estimation. 

Currently Available 

Government 

Information 

State and Local Data 

Sources 
Page 13 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

• Texas state government staff told us that they first obtained an 

estimate of the number of school-aged illegal alien children younger 

than 18 living in Texas, from a nongovernment organization.28 The 

Texas staff then multiplied this figure by the upper and lower bounds 

of a range based on alternative assumptions about the percentages of 

such children attending public schools—66.8 to 74.8 percent.29

• Pennsylvania’s state government staff told us told us that they 

estimated the number of illegal immigrant schoolchildren in terms of a 

range by (1) accepting DHS’s estimate for the resident illegal immigrant 

population in their state and (2) assuming that schoolchildren 

represent 10 to 18 percent of this population.30 The staff then multiplied 

the upper and lower bounds of the range by average per pupil 

expenditures—and also specified an estimate of additional 

expenditures for supplemental services such as ELL programs. 

• North Carolina did not provide documentation of its specific methods 

of estimation. 

We did not evaluate the estimation procedures these states used. The 

annual cost estimates that they provided to us ranged from $50 million to 

$87.5 million in Pennsylvania to $932 million to $1.04 billion in Texas.31

Of the 17 states that said they did not have information on the costs of 

schooling illegal alien children, 6 indicated that it would be illegal to ask 

about children’s immigration status. Three of these 6 mentioned the 1982 

U.S. Supreme Court decision we cited earlier; these states’ interpretation 

 28At the request of the Texas state demographer, an immigration expert at The Urban 

Institute, Washington, D.C., estimated this figure indirectly, using census and other data. 

We did not evaluate that estimate. 

29Texas based this range on data, indicating that, overall, 74.8 percent of Texas children 

under age 18 attend school and 66.8 percent attend public school. 

30They told us that 18 percent of households in Pennsylvania have school-age children and 

that they expected this figure to be lower for the resident illegal alien population because it 

is likely that some families of illegal aliens remain in their native land. 

31Pennsylvania state government staff estimated a range of $38.1 million to $66.3 million for 

current average per pupil expenditures ($7,772) and possible additions to these costs of 

$12.2 million to $21.2 million for ELL and other special programs. These two ranges total 

$50 million to $87.5 million. 
Page 14 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

of this U.S. Supreme Court decision may be overly cautious.32 (Of course, 

regardless of legal issues, a state or school district might determine that 

asking about immigration status would be inadvisable or inappropriate.) 

The six local governments or school districts that we contacted did not 

provide estimates of either the costs of educating or the numbers of illegal 

alien schoolchildren, suggesting a lack of widespread local government 

ability or effort to make such estimates. However, one school district, on 

the southwest border, identified the problem of schoolchildren who 

resided in Mexico and crossed the border daily or weekly to attend U.S. 

schools in border areas.33

Outreach through the U.S. Conference of Mayors yielded one local area 

estimate. San Jose, California, estimated the presence of approximately 

20,000 illegal alien school children—noting, however, that no study had 

been done. In other responding areas, various city officials said that, given 

the 1982 U.S. Supreme Court decision that we mentioned above, they did 

not ask about children’s immigration status.34 Of course, only a complete 

census of school districts could assess the number of local areas that 

actually have or have not developed data or specific methodological 

procedures for making estimates. 

Federal data sources are also limited. NCES and the Census Bureau 

routinely collect a variety of education data, including school enrollments 

and dollar expenditures, with annual figures for 

 32The Supreme Court’s decision in Plyler v. Doe, 457 U.S. 202 (1982), said only that children 

may not be denied education on the basis of their immigration status. Subsequently, a 1997 

district court case (League of United Latin American Citizens v. Wilson, 997 F.Supp. 1244 

(C.D. Cal. 1997)) declared unconstitutional a provision in California’s Proposition 187 that 

required schools to verify the status of schoolchildren because the Court found that the 

intent of the requirement was to deny the students access to a public education. 

Presumably, a state or local government could inquire about legal status for another, 

constitutional reason (such as to seek federal reimbursement). 

33The Superintendent of Nogales Unified School District #1 informally estimated, from 

anecdotal information, including observations of children in Nogales school uniforms 

crossing the border, that in his school district such children might number 400 to 600. He 

said that based on Arizona’s average annual per pupil expenditures of $5,000, he estimates 

the annual cost of such children at about $2 million to $4 million. 

34These cities include Anchorage, Alaska; Boston, Massachusetts; Dayton, Ohio; Lincoln, 

Nebraska; Oklahoma City, Oklahoma; St. Petersburg, Florida; San Leandro, California; and 

West Palm Beach, Florida. 

Federal Data and 

Estimates 
Page 15 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

• numbers of pupils, pupil-teacher ratios, ELL program use, and a 

measure of overcrowding and 

• current per pupil expenditures and capital expenditures for items such 

as facilities acquisition, construction, and computer purchases. 

NCES maintains these data and makes them available by state and by 

school district or local education agency. NCES told us that staff check the 

validity of these data by (1) comparing data from the school district-level 

survey to data from the state-level surveys and (2) examining trends for 

possible anomalies. 

NCES tallies education expenditures by set categories. Thus, expenditures 

cannot be broken down for specific types of programs—notably, the costs 

of ELL programs are not reported separately. Also, NCES collects no data 

on the number of foreign-born children enrolled in school or their 

immigration status. 

The Census Bureau also does not collect data on the legal status of 

foreign-born persons residing in the United States. As we stated in a 

previous report, 

Neither [the decennial] census nor CPS [the Current Population Survey conducted by the 

Census Bureau] asks about the legal status of noncitizens—or whether they are, in fact, 

here illegally. There are good reasons for this: such questions fall under the heading of 

‘threatening’ survey questions . . . many respondents might not answer these questions 

truthfully; and others might avoid participating altogether if they hear that such questions 

will be asked. In addition, . . . Census is concerned about privacy invasion issues.35

DHS has provided indirect, national and state-by-state estimates of the size 

of the resident illegal alien population.36 DHS estimated this population 

nationally at 7 million as of January 2000 and has published additional 

 35GAO/GGD-98-164, p. 39. 

36Immigration and Naturalization Service, “Estimates of the Unauthorized Immigrant 

Population Residing in the United States: 1990-2000.” (Washington, D.C.: Jan. 2003). 

http://uscis.gov/graphics/shared/aboutus/statistics/index.htm (May 21, 2004). 
Page 16 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

estimates for 42 states and the District of Columbia.37 As defined by DHS, 

the illegal population excludes approximately 577,000 aliens, who 

constitute several groups, including unauthorized immigrants with 

pending applications for legal permanent resident status.38

As we have explained elsewhere, 

• DHS based its 7 million estimate on two component estimates. The first 

component is an estimate of 5.5 million illegal residents who entered 

the United States between 1990 and 2000. The estimate was developed 

by using the generally accepted residual method.39 The second 

component is an estimate of 1.5 million illegal residents who entered 

before 1990 and were still here, illegally, in 2000. With respect to this 

estimate of 1.5 million, DHS has not published an explanation of the 

base figure or starting point of its calculations—3.5 million illegal 

immigrants here as of 1990. DHS did specify the subsequent steps that 

it used to determine how many of the 3.5 million were still here and 

still illegal as of 2000. (We note that the 3.5 million base figure is 

consistent with other available estimates for 1990.)40

 37In addition to estimates for 42 states published in Immigration and Naturalization Service, 

“Estimates of the Unauthorized Immigrant Population Residing in the United States: 1990-

2000,” DHS provided us with unpublished estimates for 4 more states (New Hampshire, 

South Dakota, West Virginia, and Wyoming), rounded to the nearest thousand. DHS told us 

estimates for the 4 remaining states (Maine, Montana, North Dakota, and Vermont) 

rounded to zero. 

38There are about (1) 200,000 unauthorized immigrants who have submitted applications 

for lawful permanent resident alien status that are pending and likely to be approved and 

(2) 377,000 aliens in various groups. The latter include aliens, mostly from Central America, 

who otherwise would be unauthorized residents but are allowed to remain and work in the 

United States under various legislative provisions or court rulings, such as people with 

Temporary Protected Status (TPS), asylees, and parolees. TPS derives from the U.S. 

Attorney General’s designating foreign nationals eligible for temporary refuge. “Asylee” 

refers to an alien granted asylum, “parolee” to an alien otherwise inadmissible but allowed 

to enter temporarily for urgent humanitarian reasons or significant public benefit. 

39The residual method consists of (1) deriving estimates of legal immigrants, based 

primarily on DHS’s own administrative data, and (2) subtracting these estimates of legal 

immigrants from the census figure for the total number of aliens residing here. DHS’s 

calculations were completed separately for different years of arrival in the United States; 

that is, census data include a report of the year in which each foreign-born individual came 

to the United States to live, and DHS administrative data indicate the year in which each 

legal immigrant entered. 

40See U.S. General Accounting Office, Overstay Tracking: A Key Component of Homeland 

Security and a Layered Defense. GAO-04-82. (Washington, D.C., May 21, 2004), app. III. 
Page 17 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

• By definition, DHS’s estimates of the resident illegal immigrant 

population do not include short-term illegal aliens—for example, 

persons here for weeks or months and not likely to be included in the 

decennial census (or corrections for undercounts).41

• DHS has stated that its national estimates are marked by uncertainty—

noting, for example, “actual trends might be somewhat higher or lower 

than those shown”—but has not developed ranges to characterize this 

uncertainty.42

DHS’s published state-by-state estimates of illegal immigrant residents 

cover 42 states and the District of Columbia. These estimates are based, in 

part, on comparing legal immigrants’ statements about their intended 

destinations, as reflected in INS administrative records when they were 

admitted to the United States, to decennial census geographic 

distributions for the total population of foreign-born residents.43 However, 

these state-level estimates are uncertain to the extent that legal 

immigrants moved to different states from the states of their intended 

destinations, at any time before the 2000 census—and some did move to a 

different state.44

Information not provided by DHS is also problematic. First, the DHS paper 

presenting these indirect estimates does not include ranges so that other 

analysts can gauge the degree of uncertainty—and hence their suitability 

for specific purposes. For example, DHS does not indicate whether some 

state estimates may be highly uncertain. Second, DHS has not published 

 41Similarly, DHS’s estimates do not, by definition, include children who reside in Mexico 

and cross the border daily or weekly to attend U.S. schools in border areas. 

42DHS’s paper, “Estimates of the Unauthorized Immigrant Population Residing in the 

United States: 1990-2000,” discusses limitations of its data, including the complexity of 

estimating numbers of persons residing here with legal temporary visas (such as temporary 

workers and students), and so forth. The paper does not, however, attempt to validate 

assumptions about emigration (how many legal and illegal immigrants leave the United 

States). 

43DHS calculates state estimates of illegal immigrants by, essentially, subtracting state-level 

estimates of legal immigrants—based on these immigrants’ statements about their intended 

state of residence, on their applications—from the total number of foreign-born persons 

residing in each state, based on the 2000 census. 

44See, for example, Marc J. Perry and Jason P. Schachter, Migration of Natives and the 

Foreign Born: 1995 to 2000, CENSR-11 Census 2000 Special Reports (Washington, D.C.: 

U.S. Census Bureau, August 2003). 
Page 18 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

any description of analyses conducted to validate its national or state 

estimates. Third, DHS’s estimates of illegal immigrants do not break out 

age groups. This is important because it is not known whether the age 

distribution—and thus percentage of school-age children—for the illegal 

population is or is not different from that for other groups.45

The Census Bureau is developing a research plan aimed at eventually 

developing new information on the population of illegal immigrants 

residing in the United States.46 Census Bureau staff told us that the 

objective of the plan is to produce annual estimates of international 

migrants according to four statuses: (1) legal immigrants, (2) temporary 

migrants, (3) quasi-legal migrants, and (4) unauthorized migrants, “in order 

to better inform . . . population estimates.” The plan will be based on an 

indirect approach that does not involve asking census or survey questions 

about immigration status. 

Importantly, the Census Bureau anticipates that the new information will 

include indirect estimates of illegal aliens in various age groups—perhaps 

coming close to identifying the number of resident illegal alien children 

who are of school age.47 The Census Bureau staff said that it is not yet 

known how many age groups can be reliably broken out. For example, it 

might be possible to use 5-year age groups or perhaps five main age groups 

(0–17, 18–29, 30–49, 50–64, and 65 and older), but Census Bureau staff told 

us that if this is not possible, perhaps only three age groups would be 

estimated (0–17, 18–64, and 65 and older). 

 45A possible additional issue regarding information not provided concerns the fact that 

illegal alien schoolchildren may include some nonresidents—that is, Mexican children who 

cross the border each school day to attend U.S. schools. DHS’s estimates of the resident 

illegal alien population would, by definition, not include schoolchildren who reside outside 

the United States. 

46Charles L. Kincannon, Director of the Census Bureau, letter to F. James Sensenbrenner 

Jr., Chairman of the Committee on the Judiciary, U.S. House of Representatives, U.S. 

Congress, Washington, D.C., Aug. 20, 2003. The preliminary work necessary to carry out 

this plan was mentioned in a presentation to a Census Bureau advisory group (see Kevin 

Deardorff, “Immigration Research Update,” presentation to Census Information 

Conference Steering Committee, Feb. 26, 2004).

47By definition, such an estimate would not include schoolchildren who reside in Mexico 

and cross the border daily or weekly to attend U.S. schools in border areas. 

The Census Bureau’s 

Plans for Estimating 

Illegal Immigrants Are 

Preliminary 
Page 19 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

While an exact methodology has not yet been specified, the Census 

Bureau previously experimented with models for imputing temporary legal 

status (for example, possessing a valid temporary work or student visa) to 

groups of foreign-born survey respondents.48 This effort used 

administrative and other data to suggest the potential numbers of foreignborn residents with temporary legal status—by age group, as well as by 

race and country of birth. The age groups were defined as 0–17, 18–29, 30–

49, 50–64, and 65 and older. 

Census Bureau analysts reason that a similar process could be developed 

for group imputation of lawful permanent resident status (that is, green 

card status).49 If this approach were expanded to cover virtually every legal 

immigration status, then the numbers and characteristics of illegal alien 

residents could also be estimated, based on a modified residual or 

subtraction approach. 

The Census Bureau intends to use its new indirect procedures on data 

from the new American Community Survey (ACS), scheduled for full 

implementation later this year. A variety of other information sources may 

be tapped. The Census Bureau further anticipates that 

• the new information on age groups nationally will be available in 2007, 

with estimates for states—and perhaps key counties—-potentially 

available by 2009 (pending budget approvals needed for the geographic 

estimates); 

• key estimates will be made annually, and other estimates (such as 

estimates for smaller groups) will be made with 3-year or 5-year 

averages;50

 48Rachel Cassidy and Lucinda Pearson, “Evaluating Components of International Migration: 

Legal Temporary Migrants,” Working Paper 60, Population Division, Census Bureau, 

January 2002. (Census Bureau working papers report the results of research undertaken by 

Census Bureau staff and undergo a more limited review than official Census Bureau 

publications.) 

49Characteristics of persons with green cards might also be based on survey data on greencard holders developed by using one legal-status card from the “three-card method.” See 

U.S. General Accounting Office, Survey Methodology: An Innovative Technique for 

Estimating Sensitive Survey Items, GAO/GGD-00-30 (Washington, D.C., Nov. 1999), pp. 1 

and 5. 

50Thus, the size of the group for which an estimate is derived, as well as the specific 

estimation methodology, will determine the time period for initial estimates and trends. For 

example, trends based on comparing 3-year averages for two points in time with no overlap 

would not be available until 2011. 
Page 20 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

• the new estimates will include ranges to indicate a margin of 

uncertainty; and 

• an assessment of the quality of the new estimates will be conducted, 

perhaps using an expert panel. 

Census Bureau staff told us that its plan does not include estimating the 

number of illegal alien children who attend public school or estimating the 

children’s English proficiency. However, Census Bureau staff suggested to 

us that, potentially, other agencies might develop such estimates by 

combining the Census Bureau’s state-by-state age group estimates of 

illegal aliens with other information, assumptions, or models or a 

combination of them. 

The ACS asks about English proficiency and school attendance. Although 

administrative data on legal immigrants do not include this information, 

the New Immigrant Survey (NIS)—sponsored by DHS and the National 

Institute of Child Health and Human Development, in partnership with 

other federal agencies—asks a sample of new green-card holders about 

their English proficiency and their school attendance.51

We believe that Census Bureau analysts face a number of technical 

challenges in developing reasonably valid and reliable information. 

Challenges include (1) assessing coverage of the illegal alien population in 

the ACS by age group, as well as coverage of legal foreign-born residents; 

(2) developing adequate sources of information to calibrate and validate a 

model for estimating immigration status; and (3) assessing and reporting 

the levels of uncertainty associated with the estimates. 

Additionally, developing this new information resource will depend on 

continued funding approvals. Specifically, the Census Bureau’s budget 

request for 2005 indicates that increased funding (more than requested for 

 51The NIS asks for the name of the school currently attended rather than whether the 

school is public or private. (The NIS is described briefly at www.pop.upen.edu/nis (May 22, 

2004).) Information on a broader spectrum of foreign-born children legally residing in the 

United States (for example, information on their school attendance or their English 

language proficiency) might also be developed by using data gathered in a survey using one 

or more legal status cards from the three-card method (GAO/GGD-00-30). 
Page 21 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

2005) will be needed for work during fiscal years 2006 to 2008 to begin 

developing migration estimates at the state and local levels.52

Because the Census Bureau’s plan is in an early stage of development 

(detailed documents are not yet publicly available), it is not yet possible to 

judge its quality. However, when more details become available, the 

Census Bureau’s plan might be compared to DHS’s methodology to 

determine whether the Census Bureau’s approach will be likely to avoid 

the weaknesses associated with DHS’s.53

We identified four approaches to estimating the dollar costs of illegal alien 

schoolchildren by state. These four approaches to estimating dollar costs 

are not necessarily mutually exclusive; that is, some are refinements of, or 

may be used together with, one or more of the others.54

The four approaches are as follows: 

1. state-by-state multiplication; 

2. local-area refinement of state-by-state multiplication; 

3. student-needs refinement of state-by-state multiplication; and 

4. capacity-based estimation of incremental costs, also a refinement of 

state-by-state multiplication. 

The first approach consists of multiplying current average per pupil 

expenditures in each state by an indirect estimate of the number of illegal 

alien schoolchildren in that state, as illustrated in fig. 2. This approach has 

 52Census Bureau staff told us these plans are documented in Exhibit 13 of the President’s 

Fiscal Year 2005 Budget. (Exhibit 13 is about the “Measuring Migration Across U.S. 

Borders” program of the Intercensal Demographic Estimates Sub-activity.) 

53We note, however, that the Census Bureau’s plan to estimate the resident illegal alien 

population would (like DHS’s estimates) exclude short-term illegal aliens who are not 

likely to be included in the decennial census, or corrections for undercounts. Also, the 

Census Bureau’s estimates would not include illegal alien schoolchildren residing in 

Mexico who cross the border to attend school. 

54Estimation of a broad array of potential costs, including overcrowding and possible 

reductions in education quality, represents an alternative direction in assessing cost 

impacts. 

Approaches to Cost 

Estimation 

State-by-State 

Multiplication Approach 
Page 22 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

been used in the past to estimate the costs in some states of educating 

illegal alien schoolchildren.55 

Figure 2: Simplest State-by-State Estimation Approach 

A variant of this approach might take account of capital expenditures (for 

example, add per pupil capital outlays to per pupil current expenditures).56

• The main advantage of state-by-state multiplication is its simplicity: If 

input data are available, cost figures are easily calculated. Additionally, 

this approach seems logical and is easily understood. 

 55For detailed examples of using current average per pupil expenditures (and the effects of 

various assumptions about how to define such expenditures) to estimate states’ costs of 

educating illegal aliens, see Rebecca L. Clark, and others, “Costs of Providing Public 

Primary and Secondary Education to Undocumented Aliens in Seven States,” in Fiscal 

Impacts of Undocumented Aliens: Selected Estimates for Seven States (Washington, D.C.: 

The Urban Institute, September 1994), pp. 61-89, and descriptions of estimates reviewed in 

U.S. General Accounting Office, Illegal Aliens: Assessing Estimates of Financial Burden 

on California, GAO/HEHS-95-22 (Washington, D.C.: Nov. 28, 1994), and Illegal Aliens: 

National Net Cost Estimates Vary Widely, GAO/HEHS-95-133 (Washington, D.C.: July 25, 

1995). 

56A National Academy of Sciences’ (NAS) workshop discussed in Edmonston and Lee, 

Local Fiscal Effects of Immigration, raised the issue of including capital costs. Although 

NCES cautions that annual figures may vary considerably from year to year, one solution 

may be to use a summary figure, such as a 5-year average. The NAS workshop, however, 

noted “the applicability of average cost or marginal cost may be time sensitive,” depending 

on whether a school system has “significant excess student capacity” or becomes 

overcrowded (p. 16). 

Sources: GAO (analysis), NCES (per pupil expenditure data), Census Bureau (estimation plans), U.S. Department of Education (photo).

Each state's average

per pupil expenditures

Data currently available 

from National Center 

for Education Statistics

Estimated number of 

illegal alien schoolchildren 

in each state

Each state's cost of 

educating illegal alien 

schoolchildren

No government 

estimate; by 2007-09, 

Census may estimate 

illegal aliens by age

Reliable estimates 

based on government 

data are not currently 

possible
Page 23 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

• Its limitations are that it does not account for the many complexities of 

costs in this area—which, as we outlined in the background section, 

include local-area cost differentials, variation in individual student 

needs, differences in school capacity, and potentially other factors.57

Considering its advantages and disadvantages, we believe that state-bystate multiplication is a logical approach that could yield a rough 

approximation of state-by-state costs. As we outlined above, government 

data or estimates needed for using this approach are not currently 

available. Although NCES provides data on per pupil expenditures by 

state, DHS’s state-by-state estimates of the illegal immigrant population do 

not break out age groups. Moreover, DHS’s state-by-state estimates have 

methodological limitations that make them uncertain, yet DHS has not 

estimated ranges or otherwise characterized the degree of uncertainty 

associated with specific estimates. 

In the future, the Census Bureau may provide age-group estimates of 

illegal immigrants by state. 

Although there are a number of challenges, if state-level estimates of 

illegal alien children are successfully developed and validated then 

reasonably reliable (if somewhat rough) approximations of state-by-state 

costs could be calculated, using the state-by-state multiplication approach. 

This would be especially the case if others are able to refine this 

information by estimating illegal alien children’s school attendance. 

The local-area refinement approach is a logical extension of state-by-state 

multiplication and attempts to generate greater precision by taking 

account of local variations in school costs.58 Multiplications would be 

conducted separately for different areas—for example, cities, counties, or 

groups of counties—and then summed across all areas of the state. Thus, 

 57For example, the diversity (versus homogeneity) of languages and backgrounds of illegal 

immigrant children enrolled in a particular school district may affect costs. 

58In responding to our survey, New York (State Department of the Budget, Education Unit) 

pointed to geographic cost differences within states, noting that “If the unauthorized 

foreign-born students are clustered in the regions of the state where education is more 

expensive, as is most likely the case in large states like New York and California, using the 

average cost in the state as a whole will underestimate the true cost of educating these 

students.” NAS noted cost variations across geographic areas within states (Edmonston 

and Lee, Local Fiscal Effects of Illegal Immigration, p. 14). 

Local-Area Refinement of 

the State-by-State 

Multiplication Approach 
Page 24 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

if large numbers of illegal alien schoolchildren attend schools with higher 

or lower costs than the state average, this would be reflected in the cost 

estimates. This approach is appropriate for states with significant 

immigrant populations that exhibit local-area variation in both school 

costs and numbers of illegal alien schoolchildren. 

• The local-area refinement approach has the same advantages as stateby-state multiplication, and it uses more specific local-area data. 

• Its limitations are suggested by a review of other methods (discussed 

below) that account for differences in student needs or school 

capacity, each of which can affect costs. 

NCES collects and maintains current per pupil expenditure and capital 

outlay data, which are available at the school district level, but 

government information on illegal alien schoolchildren is not available. In 

the future, the Census Bureau’s plan may, if successfully implemented, 

help quantify the population of school-age illegal alien children in key 

counties. 

The student-needs refinement of the state-by-state multiplication approach 

can build on either of the two approaches we described above, by 

accounting for specific individual student needs that may affect education 

costs. As we indicated in the background section, costs may be higher for 

children in poverty or with limited English proficiency than for other 

children—and both poverty and limited English proficiency may 

characterize many illegal alien children. Moreover, of the 20 states 

responding to our survey, 5 indicated that because of special needs (such 

as for ELL programs), efforts to estimate the costs of educating illegal 

alien children should consider these additional cost factors.59 Using a costfunction approach to statistical analysis allows estimation of cost factors 

associated with meeting the needs of students with specific 

characteristics.60

 59The NAS workshop also pointed to program-specific variations in costs, for example, ELL 

(Edmonston and Lee, Local Fiscal Effects of Illegal Immigration, p. 15). 

60See, for example, William Duncombe, “Estimating the Cost of an Adequate Education in 

New York,” CPR Working Paper 44, Center for Policy Research, Maxwell School, Syracuse 

University, Syracuse, New York, February 2002. http://wwwcpr.maxwell.syr.edu/faculty/duncombe/special%20report/specialreport.htm (May 22, 2004). 

Student-Needs Refinement 

of the State-by-State 

Multiplication Approach 
Page 25 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

• The main advantage of this approach is that by focusing on individual 

students, it takes account of more determinants of cost than the other 

approaches outlined above. 

• The main disadvantage is the complexity involved in estimating cost 

factors, as well as requirements for data that may not be available. 

Additionally, this approach does not account for varying school 

capacity (see below). 

There are two key issues in implementing the student-needs-refinement 

approach: 

1. It requires data based on separate cost accounting for programs 

designed to meet special student needs. NCES state-by-state and 

school-district data do not include separate information on the cost of 

either ELL programs or programs designed to compensate for poverty 

(and associated learning disadvantages). However, information on 

revenues from federal and state sources for related programs (for 

example, bilingual education) are collected in the Annual Survey of 

Local Government Finances–School Systems, conducted by the 

Census Bureau. 

2. It also requires estimates of the English proficiency and the poverty 

status of illegal alien school children. The Census Bureau’s plan does 

not envision such estimates, but Census Bureau staff told us that other 

government agencies or researchers could expand on the information 

the Census Bureau provides by, for example, using additional 

assumptions and models to achieve indirect estimates of illegal alien 

children with limited English proficiency.61

The incremental cost of adding a student to a classroom, school, or school 

district may be much higher or lower than the average per pupil 

expenditure, depending on the capacity of the classroom, school, or 

district in question. To illustrate, adding one student to a classroom and 

school that has the capacity to easily accommodate the student would not 

 61Refer back to the earlier section entitled The Census Bureau’s Plans for Estimating Illegal 

Immigrants Are Preliminary. 

School-Capacity Approach 
Page 26 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

require additional capital outlays, such as building a new facility.62 In 

contrast, if that school were at or above capacity, the reverse might be 

true.63 

Various experts have suggested that—at least in some circumstances—a 

capacity-based approach to cost estimation may produce more meaningful 

results than the other approaches. For example, an NAS workshop on the 

fiscal effects of immigration indicated that “Over time, [education] costs 

are a function of the capacity utilization level, not simply the number of 

additional children.”64

In general, three cost categories can be distinguished, as shown in table 1. 

Category 1 costs do not vary with enrollment increases or decreases. 

Category 2 costs tend to change in a predominantly linear fashion when 

students are added. Category 3 costs, which may be related to growth in 

enrollment, tend to increase or decrease in step jumps rather than in a 

linear fashion; these may be more difficult to predict. 

 62Consistent with this is the notion that when enrollments increase, average per pupil 

expenditures may initially decline. Of course, if more students are added, a point may come 

at which—even for a school with initial excess capacity—one or more teachers must be 

added, overcrowding will occur, and additional classroom space must be acquired or new 

school must be built. 

63An example is given in Brad R. Humphreys, “A Report on Incremental Costs and Benefits 

Associated with Increasing Enrollment at UMBC,” Department of Economics, University of 

Maryland Baltimore County, Baltimore, Maryland, May 17, 2003. In preparing this report, 

we conducted a preliminary analysis of education costs in new-growth immigration states 

(including the 5 states on the right in fig. 1, and 5 other states). We found that per pupil 

expenditures in these 10 new-growth states increased by a larger amount than in other 

states, taken as a group. However, we could not conclude that there was a connection 

between immigration and the change in per pupil expenditures, because there was 

considerable overall growth in these states’ total populations. And even after high 

percentage growth in the foreign-born populations in these states, foreign-born persons 

remained a relatively small percentage of these states’ total populations. 

64Edmonston and Lee, Local Fiscal Effects of Immigration, p. 16. 
Page 27 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

Table 1: Cost Categories Relevant to the School-Capacity Approach 

Cost category Cost example 

1. Fixed costs • maintaining a school board 

• salary of the superintendent of schools 

2. Variable costs that correspond directly to the number of students • new textbooks 

• other materials purchased for each student 

3. Costs incurred when capacity is expanded • adding teachers 

• adding on to an existing school or building a new school 

Source: GAO analysis. 

For a classroom with excess capacity, the only costs associated with 

adding a single student would be category 2 costs.65 Where capacity is 

limited or already stretched, both category 2 and category 3 are relevant. 

Calculating category 3 costs is difficult. However, studies to explore the 

incremental costs of illegal alien children might be approached by 

developing matched pairs of school districts—that is, school districts that 

appear to have many relevant characteristics in common but that differ 

with respect to enrollment of illegal alien schoolchildren over time. 

• The advantage of the school-capacity approach is that it reflects 

important classroom and school factors for which the other 

approaches do not account. 

• The main disadvantages are its complexity and requirements for 

extensive, specific data that may not be available. 

Separate data for each cost category in table 1 are not necessarily easily 

accessed. Although some expenditures within a category (such as paper 

supplies, books, and periodicals in category 2) can be broken out in NCES 

data, the costs of adding teachers because of expanding enrollments could 

probably be estimated only by undertaking a special study, such as that 

suggested above. In the future, the Census Bureau may be able to supply 

the data needed to (1) help identify candidate counties or districts for such 

studies and (2) track trends in the estimated numbers of illegal alien 

schoolchildren in these areas over time. NCES school-expenditure data 

could then be compared over time—ideally, before and after a period of 

 65In fact, the slightly larger class size would, all other things being equal, tend to result in a 

decline in average per pupil expenditures. 
Page 28 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

substantial growth in the illegal alien enrollments for one of the two 

school districts. 

Considering our findings, we believe that the government information that 

is available is not sufficient to reliably quantify the costs of educating 

illegal alien schoolchildren. All approaches to estimating these costs 

require data or estimates of the number of illegal alien schoolchildren. 

Neither state nor local governments collect this information, and federal 

agencies do not provide estimates. 

Although DHS estimates the resident illegal immigrant population, its 

estimates are subject to unspecified levels of uncertainty; further, DHS 

estimates do not break out age groups. The Census Bureau plans to 

develop age-group estimates, but it is too early to evaluate its plans. If 

successfully implemented, the plan calls for national estimates to be made 

available by 2007 with state and perhaps local estimates by 2009. 

If more data on the numbers and characteristics of illegal alien 

schoolchildren were to become available, then it would be appropriate to 

conduct an in-depth analysis of the methodological alternatives that could 

be supported by those data. If feasible, analyses aimed at producing 

comparative estimates, based on more than one approach, could shed 

considerable light on the issue of education costs. They could do so by 

indicating not only the expenditure levels based on the numbers of illegal 

alien pupils and the average per pupil expenditures by state or local area. 

They could also do so by providing information on whether estimated 

expenditures are appreciably different when adjusted to reflect these 

students’ needs or the capacity of the schools they attend or both. 

We provided a draft of this report to the Census Bureau, DHS, and NCES. 

The agencies informed us that they had no formal comments, but we 

received informal comments from the Census Bureau and NCES on minor 

technical points and made changes in the report as appropriate. 

As agreed with your office, we will be sending copies of this report to the 

Secretary of the Department of Homeland Security, the Director of the 

National Center for Education Statistics, the Director of the Census 

Bureau, and various congressional committees. We will also make copies 

available to others on request. In addition, the report will be available at 

no charge on the GAO Web site at http://www.gao.gov. 

Observations 

Agency Comments 
Page 29 GAO-04-733 Estimating Costs of Illegal Alien Schoolchildren

If you or your staff would like to discuss any of the issues we present here, 

please call me at (202) 512-2700 or Judith A. Droitcour, who served as 

project director on this study, at (202) 512-9145. Other major contributors 

to this report include Eric M. Larson, Mona H. Sehgal, Seyda Wentworth, 

and Timothy Carr. 

Sincerely yours, 

Nancy R. Kingsbury, 

Managing Director 

Applied Research and Methods 

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