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June 2004:

Illegal Alien Schoolchildren:

Issues in Estimating State-by-State Costs:


GAO Highlights:

Highlights of GAO-04-733, a report to the Chairman of the Committee on 
the Judiciary, House of Representatives 

Why GAO Did This Study:

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 cost-estimation 

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.

What GAO Found:

Current government information is not sufficient to directly estimate 
the state-by-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: 

[See PDF for image]

[End of figure]

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

[End of section]



Results in Brief:


Objectives, Scope, and Methodology:

Currently Available Government Information:

The Census Bureau's Plans for Estimating Illegal Immigrants Are 

Approaches to Cost Estimation:


Agency Comments:


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


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

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


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:

United States General Accounting Office:

Washington, DC 20548:

June 23, 2004:

The Honorable F. James Sensenbrenner, Jr.: 
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.[Footnote 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.[Footnote 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 
interviews at federal agencies, performed a literature review, and 
consulted with experts.

Results in Brief:

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 

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 state-
by-state estimates of the size of the resident illegal population, but 
these estimates do not break out age groups; the DHS estimates are 
subject to methodological limitations as well.[Footnote 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.[Footnote 4] Yet another approach assesses the 
role of enrollment growth, school capacity, and "incremental 
costs."[Footnote 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 alien.[Footnote 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,[Footnote 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,[Footnote 8] and:

3. the Congress could authorize federal reimbursement of the costs of 
providing K-12 education to illegal alien children, based on the state-
by-state costs of educating them or on the estimated numbers residing 
in each state.[Footnote 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 Costs May Be Heightened:

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-
-totaled about $324 billion. Capital outlays in that school year--for 
facilities acquisition and construction--were an additional $35 
billion.[Footnote 10] These costs were borne primarily at state and 
local levels; federal dollars represented about 7 percent of school 
revenue.[Footnote 11]

The Immigration and Naturalization Service (INS) estimated that the 
illegal immigrant population increased to 7 million as of January 
2000.[Footnote 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 

* Many state and local budgets are squeezed, and education costs 
represent their largest expenditure item.[Footnote 13]

* 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.[Footnote 14]

Immigration Levels and Education Costs Vary across Areas:

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 ½ 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.

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

[See PDF for image]

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

[End of figure]

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:

* $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 Utah[Footnote 15]

Local areas can also vary in terms of both immigration concentration 
and per pupil expenditures, despite equalization rules and programs in 
some states.[Footnote 16]

Two California areas serve as illustration.[Footnote 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 Are Related to Costs:

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 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).[Footnote 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.[Footnote 19]

The costs of meeting the needs of such students have been variously 
estimated. Bringing ELL-enrolled children up to the grade level of 
same-age 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.[Footnote 20] 
Bringing students 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.[Footnote 21]

Objectives, Scope, and Methodology:

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:

4. 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?

5. What is the Census Bureau's plan for developing new information on 
the illegal alien population in the future?

6. 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 
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).[Footnote 22]

* Telephone or e-mail inquiries to six local government or school 
district officials (question 1).[Footnote 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).[Footnote 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).[Footnote 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 quantify net impacts.[Footnote 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.[Footnote 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.

Currently Available Government Information:

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.

State and Local Data Sources:

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:

* 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.[Footnote 
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.[Footnote 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.[Footnote 
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.[Footnote 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 of this U.S. Supreme Court decision may be 
overly cautious.[Footnote 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.[Footnote 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.[Footnote 
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 and 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:

* 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.[Footnote 35]

DHS has provided indirect, national and state-by-state estimates of the 
size of the resident illegal alien population.[Footnote 36] DHS 
estimated this population nationally at 7 million as of January 2000 
and has published additional estimates for 42 states and the District 
of Columbia.[Footnote 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.[Footnote 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.[Footnote 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.)[Footnote 40]

* 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).[Footnote 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.[Footnote 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.[Footnote 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.[Footnote 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 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.[Footnote 45]

The Census Bureau's Plans for Estimating Illegal Immigrants Are 

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.[Footnote 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.[Footnote 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).

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.[Footnote 48] This effort 
used administrative and other data to suggest the potential numbers of 
foreign-born 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).[Footnote 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 

* 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;[Footnote 50]

* 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.[Footnote 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 2005) will be needed for work during fiscal years 2006 to 2008 to 
begin developing migration estimates at the state and local 
levels.[Footnote 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.[Footnote 53]

Approaches to Cost Estimation:

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.[Footnote 54]

The four approaches are as follows:

7. state-by-state multiplication;

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

9. student-needs refinement of state-by-state multiplication; and:

10. capacity-based estimation of incremental costs, also a refinement 
of state-by-state multiplication.

State-by-State Multiplication Approach:

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 been used in the past to estimate the costs in some 
states of educating illegal alien schoolchildren.[Footnote 55]

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

[See PDF for image]

[End of figure]

A variant of this approach might take account of capital expenditures 
(for example, add per pupil capital outlays to per pupil current 
expenditures).[Footnote 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 

* 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.[Footnote 57]

Considering its advantages and disadvantages, we believe that state-by-
state 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.

Local-Area Refinement of the State-by-State Multiplication Approach:

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.[Footnote 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, 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 state-
by-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.

Student-Needs Refinement of the State-by-State Multiplication 

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.[Footnote 59] Using a cost-function approach to 
statistical analysis allows estimation of cost factors associated with 
meeting the needs of students with specific characteristics.[Footnote 

* 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 

11. 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.

12. 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.[Footnote 61]

School-Capacity Approach:

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 require additional capital outlays, such as building a new 
facility.[Footnote 62] In contrast, if that school were at or above 
capacity, the reverse might be true.[Footnote 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."[Footnote 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 

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

Cost category: 1. Fixed costs; 
Cost example: 
* maintaining a school board; 
* salary of the superintendent of schools.

Cost category: 2. Variable costs that correspond directly to the number 
of students; 
Cost example: 
* new textbooks; 
* other materials purchased for each student.

Cost category: 3. Costs incurred when capacity is expanded; 
Cost example: 
* adding teachers; 
* adding on to an existing school or building a new school.

Source: GAO analysis.

[End of table]

For a classroom with excess capacity, the only costs associated with 
adding a single student would be category 2 costs.[Footnote 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 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 

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.

Agency Comments:

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

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,

Signed by: 

Nancy R. Kingsbury, Managing Director:

Applied Research and Methods:


[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.

[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.

[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).

[10] An additional $22 billion was spent on other categories and 
programs, some not part of K-12 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 

[11] Local 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. 

[12] U.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.

[13] See 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."

[14] U.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.

[15] Table 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. 
(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.

[16] In 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. (May 19, 2004).

[17] Table 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. (May 17, 2004).

[18] See the Education Alliance at Brown University, http:// (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.

[19] See 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).

[20] See 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.

[21] See 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.

[22] We 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.

[23] We 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). 

[24] Other 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.

[25] These 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.

[26] We 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.

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

[28] At 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 

[29] Texas 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. 

[30] They 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.

[31] Pennsylvania 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.

[32] The 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 

[33] The 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.

[34] These cities include Anchorage, Alaska; Boston, Massachusetts; 
Dayton, Ohio; Lincoln, Nebraska; Oklahoma City, Oklahoma; St. 
Petersburg, Florida; San Leandro, California; and West Palm Beach, 

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

[36] Immigration and Naturalization Service, "Estimates of the 
Unauthorized Immigrant Population Residing in the United States: 1990-
2000." (Washington, D.C.: Jan. 2003).
shared/aboutus/statistics/index.htm (May 21, 2004).

[37] In 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.

[38] There 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.

[39] The 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 

[40] 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.

[41] Similarly, 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.

[42] DHS'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).

[43] DHS 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. 

[44] See, 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).

[45] A 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.

[46] Charles 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).

[47] By 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.

[48] Rachel 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.) 

[49] Characteristics of persons with green cards might also be based on 
survey data on green-card 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.

[50] Thus, 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.

[51] The 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 (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).

[52] Census 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.) 

[53] We 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. 

[54] Estimation of a broad array of potential costs, including 
overcrowding and possible reductions in education quality, represents 
an alternative direction in assessing cost impacts.

[55] For 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).

[56] A 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).

[57] For example, the diversity (versus homogeneity) of languages and 
backgrounds of illegal immigrant children enrolled in a particular 
school district may affect costs.

[58] In 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).

[59] The NAS workshop also pointed to program-specific variations in 
costs, for example, ELL (Edmonston and Lee, Local Fiscal Effects of 
Illegal Immigration, p. 15).

[60] See, 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.
special%20report/specialreport.htm (May 22, 2004).

[61] Refer back to the earlier section entitled The Census Bureau's 
Plans for Estimating Illegal Immigrants Are Preliminary.

[62] Consistent 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.

[63] An 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. 

[64] Edmonston and Lee, Local Fiscal Effects of Immigration, p. 16.

[65] In fact, the slightly larger class size would, all other things 
being equal, tend to result in a decline in average per pupil 

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