POPULATION DIVISION

Working Paper #58

Evaluating Components of International Migration:

Estimates of the Foreign-Born Population by Migrant 

Status in 2000

Kevin E. Deardorff 

Lisa M. Blumerman
ii

Synopsis

On March 1, 2001, the U.S. Census Bureau issued the recommendation of the Executive Steering

Committee for A.C.E. Policy (ESCAP) that the Census 2000 Redistricting Data not be adjusted based

on the Accuracy and Coverage Evaluation (A.C.E.). By mid-October 2001, the Census Bureau had

to recommend whether Census 2000 data should be adjusted for future uses, such as the census long

form data products, post-censal population estimates, and demographic survey controls. In order to

inform that decision, the ESCAP requested that further research be conducted.

Between March and September 2001, the Demographic Analysis-Population Estimates (DAPE)

research project addressed the discrepancy between the demographic analysis data and the A.C.E.

adjusted estimates of the population. Specifically, the research examined the historical levels of the

components of population change to address the possibility that the 1990 Demographic Analysis

understated the national population and assessed whether demographic analysis had not captured the

full population growth between 1990 and 2000. Assumptions regarding the components of

international migration (specifically, emigration, temporary migration, legal migration, and unauthorized

migration) contain the largest uncertainty in the demographic analysis estimates. Therefore, evaluating

the components of international migration was a critical activity in the DAPE project.

This report focuses on the evaluation of the U.S. Census Bureau’s estimates of the foreign-born

population by migrant status in 2000. In particular, we assess the assumptions used to estimate the

various types of international migrants (legal immigrants, temporary migrants, unauthorized migrants, and

emigrants) and the effect of alternative assumptions in estimating the size of the foreign-born population. 

By reviewing alternative assumptions about the types of international migrants, we assess the

completeness of coverage of the foreign-born population in Census 2000, and the reasonableness of

the resulting Demographic Analysis (DA) estimates.
iii

Table of Contents

SYNOPSIS ................................................................... ii

INTRODUCTION ............................................................. 1

BACKGROUND .............................................................. 1

Defining the Components of the Foreign-Born Population ................................. 1

Legal Immigrants ......................................................... 1

Foreign-Born Emigrants .................................................... 2

Mortality ............................................................... 2

Temporary Migrants ....................................................... 2

Residual Foreign Born ..................................................... 3

DETAILED METHODOLOGY ................................................... 4

Data Sets Used for Calculations .................................................... 4

Review of Previous Methodology Used to Calculate the Foreign-Born Population by Migrant

Status ....................................................................... 5

Evaluation of the Methodology Used to Calculate the Foreign-Born Population by Migrant 

Status ....................................................................... 5

Evaluation Question 1 ...................................................... 6

Evaluation Question 2 ...................................................... 6

Evaluation Question 3 ...................................................... 7

RESULTS OF ALTERNATIVE ASSUMPTIONS ..................................... 7

Assumptions for the DAPE Estimate of the Foreign-Born Population ......................... 8

Assumptions for the DAPE Lower-Bound Estimate of the Foreign-Born Population ............. 8

Assumptions for the DAPE Upper-Bound Estimate of the Foreign-Born Population .............. 9

Implications and Reasonableness .................................................. 10

REFERENCES ............................................................... 12

APPENDIX 1: EQUATIONS FOR DAPE ....................................... A-1

Equations for Estimating the Foreign-Born Population by Migrant Status ................... A-1

Equation A. DAPE Estimate of the Foreign-Born Population by Migrant Status ....... A-1

Equation B. DAPE Lower-Bound Estimate of the Foreign-Born Population by 

Migrant Status ........................................................ A-2

Equation C. DAPE Upper-Bound Estimate of the Foreign-Born Population by 

Migrant Status ........................................................ A-3
iv

APPENDIX 2: DAPE WORKING PAPER SERIES BIBLIOGRAPHY .................. B-1

List of Tables

Table 1: Census Level Estimates of the Foreign-Born Population by Migrant Status in 2000: 

Baseline .............................................................. 3

 

Table 2: “True” Level Estimates of the Foreign-Born Population by Migrant Status in 2000: 

Baseline .............................................................. 4

Table 3: “True” Level Estimates of the Foreign-Born Population by Migrant Status in 2000: 

DAPE Estimate ......................................................... 8

Table 4: “True” Level Estimates of the Foreign-Born Population by Migrant Status in 2000: LowerBound DAPE Estimate ................................................... 9

Table 5: “True” Level Estimates of the Foreign-Born Population by Migrant Status in 2000: 

Upper-Bound DAPE Estimate ............................................. 10

Table 6: Census Level Undercoverage Rate Assumptions for the Foreign-Born Population by 

Migrant Status: 2000 .................................................... 10

Table 7: Effect of Alternative Assumptions for the Foreign-Born Population on Demographic 

Analysis Estimates ...................................................... 11
1

INTRODUCTION

This report presents a discussion of the components of the foreign-born population and focuses on the

findings from the Demographic Analysis-Population Estimates (DAPE) research project. In particular,

we assess the assumptions used to estimate the various types of international migrants (legal immigrants,

temporary migrants, unauthorized migrants, and emigrants) and the effect of alternative assumptions in

estimating the size of the foreign-born population. By reviewing alternative assumptions about the types

of international migrants, we assess the completeness of coverage of the foreign-born population in

Census 2000, and the reasonableness of the resulting Demographic Analysis (DA) estimates.

BACKGROUND

The foreign-born population is defined by the U.S. Census Bureau as people who are not U.S. citizens

at birth. 

Defining the Components of the Foreign-Born Population (FB)

The foreign born consist of legal immigrants, temporary migrants, and unauthorized migrants (Deardorff,

2001b). Stated as an equation, the foreign-born population is defined as:

FB = [L - (M + E)] + T + R

where

FB = Foreign-born population

L = Legal immigrants

M = Mortality to legal immigrants

E = Emigration of legal immigrants

T = Temporary (legal) migrants

R = Residual foreign born (unauthorized and quasi-legal migrants)

For the foreign-born population, we estimated demographic characteristics (age, sex, race, and

Hispanic origin) for implied legal status (legal immigrants, temporary migrants, and residual foreign born)

by place of birth, defined for DAPE as 40 unique groupings of countries (see Mulder et al., 2001).

Legal Immigrants (L)

The Immigration and Nationality Act defines legal immigration as the process by which a non-citizen of

the United States is granted legal permanent residence. A non-citizen with legal permanent residence

status may remain in the country, be employed, travel freely, and seek naturalization to become a U.S.
2

citizen. Legal immigrants, as categorized by the Census Bureau, include new arrivals to the United

States, people adjusting their migrant status to legal permanent resident (including Special Agricultural

Workers (SAWs) and pre-1982 entrants (LAWs)), asylees, and refugees (Perry et al., 2001). 

We estimated the number of legal immigrants using Immigration and Naturalization Service (INS) data. 

In 2000, the estimate of survived legal immigrants ([L - (M + E)]) was 21,612,023. 

Foreign-Born Emigrants (E)

Foreign-born legal emigrants were residents of the United States who departed from the United States

to reside abroad. Unauthorized migrants, migrants from Puerto Rico, temporary migrants, and natives

(U.S. citizens at birth) are excluded from this population universe. For purposes of the DAPE project,

we estimated the number of emigrants from a residual methodology using data on the foreign-born

population by period of entry from two consecutive censuses (Mulder et al., 2001). We used the

resulting number of emigrants to calculate rates of emigration. Although these emigration rates reflect

the behavior of the entire foreign-born population, they were used as a reasonable proxy for the legal

immigrant population. By applying these emigration rates to the legal immigrant population annually

from 1990 to 2000, we estimated the number of emigrants from the legal population between 1990 and

2000.

Mortality (M)

Survival rates for the legal immigrant population were calculated from life tables of the total population

by sex and single year of age (Mulder et al., 2001). Although these survival rates were calculated for

the total population, they were used as a reasonable proxy for the legal 

immigrant population. By applying these survival rates to the legal immigrant population, we estimated

the number of deaths that occurred to this population between 1990 and 2000.

Temporary Migrants (T)

The Immigration and Nationality Act defines temporary migrants (also referred to as nonimmigrants) as

aliens admitted to the United States for a specified purpose and temporary period, but not for

permanent residence. Temporary migrants, as categorized by the Census Bureau and defined for the

remainder of this paper, include those who would be considered 

residents of the United States for purposes of the decennial census, including foreign students and

temporary workers, but excluding tourists and business workers (see Cassidy and Pearson, 2001).

We estimated temporary migrants using INS data. In 2000, the estimate of temporary migrants was

1,200,000. 
3

Residual Foreign Born (R)

The residual foreign born, as categorized by the Census Bureau, include the foreign born who were not

otherwise accounted for in a legal migration component, whether or not they were counted in the

census (Costanzo et al,. 2001). Although the residual foreign born include mostly unauthorized

migrants, it also includes some categories of legal (or “quasi-legal”) migrants for whom data were not

available. Later in our evaluation section, we have attempted to account for this shortcoming by

separating the residual foreign born into known components of the foreign born (e.g., immigrants such

as asylee applicants who were in a processing backlog at the INS, most of whom will become legal

permanent residents) and the implied unauthorized population (Costanzo et al., 2001; Deardorff,

2001a; Deardorff, 2001b). Therefore, the residual foreign born is actually: 

R = R1 + R2

where 

R1 = Known components of the residual foreign born (mostly quasi-legal migrants)

R2 = Implied unauthorized migrants

We estimate known components of the residual foreign born (R1) using INS data. In 2000, the

estimate of this group was 1,700,000. We estimate unauthorized migrants (R2) by applying undercount

rate assumptions to the part of this population counted in the census.

Researchers have not agreed on how many unauthorized migrants were missed in the census. 

However, after reviewing research conducted by independent migration experts, and after reviewing the

results for hard-to-count populations from the Accuracy and Coverage Evaluation (A.C.E.), we

assumed a 15-percent average undercount for the foreign born enumerated in the census and

categorized as residual foreign born (see Table 1). Applying this average 15-percent undercount to the

residual foreign born counted in the census, we estimated the following “true” level of foreign born by

migrant status in 2000 (see Table 2).

Table 1: Census Level Estimates of the Foreign-Born Population by Migrant Status in 2000: Baseline 

Migrant Status Number

Foreign Born Population 31,098,945

 Survived Legal Immigrants (implied) 21,612,023

 Temporary Migrants1 781,507

 Residual Foreign Born 8,705,419

1 Estimates of temporary migrants were calculated from the census using previous census methodology.

Components of the foreign born do not add to the total foreign born due to rounding in underlying calculations.
4

Table 2: “True” Level Estimates of the Foreign-Born Population by Migrant Status in 2000: Baseline

 

Migrant Status Number

Foreign Born 32,635,199

 Survived Legal Immigrants (implied) 21,612,023

 Temporary Migrants1 781,507

 Residual Foreign Born 10,241,669

1 For the Baseline estimates, we assumed complete census coverage for temporary migrants. For subsequent

scenarios, we assumed a “true” level estimate of temporary migrants of 1,200,000.

The demographic analysis estimates presented in detail in the main section of this report used the levels

of temporary migrants and unauthorized migrants (counted within the residual foreign born) shown

above. These levels represent the results of detailed analysis and the application of detailed age, sex,

race, and Hispanic origin distributions. 

DETAILED METHODOLOGY

Previous estimates of the foreign-born population by migrant status used a variety of often unrelated

data sets. Using different data sets to estimate types of international migrants is problematic given the

residual methodology used previously and in this analysis. To minimize inconsistencies, we used an

integrated approach to calculate the migrant status of the foreign born. Additionally, we generated

standardized files for the 1990 Census and Census 2000 data which were used for the calculations of

the number of each type of international migrant. We also used a standard method to impute values for

missing variables and characteristics in these files. 

Data Sets Used for Calculations

For temporary migrants, data from the Census 2000 Supplementary Survey were used as a proxy for

Census 2000 data that were not yet available. A review and evaluation of these data suggest they are a

reasonable approximation for yet unavailable detailed Census 2000 sample data (Malone, 2001;

Deardorff and Malone, 2001).

For 1990, we used the census sample edited detail file modified to remove the category of “some other

race.” Missing data for country of birth were imputed using responses to the country of birth question,

independently for each state. For 2000, we used preliminary census sample data, based on

intermediate weighting schemes and editing procedures, and modified to match the 1990 racial

categories (Malone, 2001). The preliminary Census 2000 sample data were available only for certain

variables, including age, sex, race, Hispanic origin, country of birth, citizenship, and year of entry into

the United States.
5

Using these data sets, we estimated the foreign born in 2000 by migrant status (legal immigrants,

temporary migrants, and a residual component consisting of quasi-legal and unauthorized migrants) by

DA race (Black, NonBlack), sex, and A.C.E. age groups (ages 0-17, 18-29, 30-49, and 50 and

older). In addition, we estimated the number of foreign born by migrant status, sex, A.C.E. age groups,

and mutually exclusive race/ethnic categories (non-Hispanic White, non-Hispanic Black, non-Hispanic

Asian and Pacific Islander, non-Hispanic American Indian and Alaska Native, and Hispanic).

Review of Previous Methodology Used to Calculate the Foreign-Born Population by Migrant Status

Historically, the Census Bureau employed demographic analysis to evaluate the accuracy of census

results. In the course of these evaluations, the Census Bureau made assumptions regarding the level of

legal migrants and the residual foreign born. Based on previous research about census coverage of these

populations, the Census Bureau traditionally assumed a higher coverage rate for legal immigrants than

for the residual foreign born (Costanzo et al., 2001). After the 1990 Census, the Census Bureau

expanded estimates of international migrants to include temporary migrants to the United States, as

previous estimates of temporary migrants were limited to the number of foreign students in the country. 

A primary reason for estimating temporary migrants was to account for this group independently of the

unauthorized population in the decennial census. Other reasons were to develop better demographic

characteristics of the foreign-born population (specifically, temporary migrants do not age during the

decade because of legal requirements restricting length of stay in the United States), and to evaluate the

upcoming results of Census 2000.

A major component of the DAPE project was to validate estimates of the number of international

migrants (legal immigrants, temporary migrants, and unauthorized migrants) in 1990. After our

validation work, we used the same methodologies to develop estimates of the number of international

migrants for 2000 using available data. Independent teams were formed to evaluate work on each of

these components of international migration. For detailed descriptions of how the teams revised and

improved previous estimates, see Costanzo et al., 2001; Mulder et al., 2001; Cassidy and Pearson,

2001; and Perry et al., 2001.

Evaluation of the Methodology Used to Calculate the Foreign-Born Population by Migrant Status

Although researchers have routinely adjusted census level estimates of unauthorized migrants to account

for those missed in the census, they usually do not adjust explicitly for similar undercounts to the legal

immigrant and temporary migrant populations (Passel, 2001; Bean et al., 2001). 
6

To assess the robustness of these levels to varying assumptions about the undercount of legal

immigrants and temporary migrants, we developed several scenarios. As discussed later, the

application of alternative assumptions results in different implied total foreign-born populations by

migrant status. Nevertheless, the totals are not different enough to greatly affect the total DA 

estimates. Thus, while the results based on the 15-percent assumptions discussed above could vary,

the variations would not be substantively different.

This evaluation of the methodology used to calculate the components of international migration

addressed several questions:

1) Was the assumption of complete coverage of legal immigrants and temporary migrants in

the census reasonable?

2) Was the assumption of 15-percent undercount for all residual foreign born reasonable?

3) Was the resulting estimate of the residual foreign born a reasonable approximation of

unauthorized migrants?

Evaluation Question 1

When assigning the foreign born counted in the census to migration statuses, previous researchers at the

Census Bureau assumed complete (100 percent) coverage of legal immigrants and temporary migrants

in the decennial census. Because the residual foreign born were calculated in the residual category

(foreign-born population minus the sum of legal immigrants and temporary migrants), the number of

foreign born counted in the census who were categorized as the residual foreign born would be even

higher if the assumption of complete coverage of legal immigrants and temporary migrants was

dropped.

Researchers studying the foreign born, both inside and outside the Census Bureau, agreed that an

assumption of complete coverage for legal immigrants and temporary migrants was unreasonable

(Deardorff and Cresce, 2001). A change to this assumption of full coverage in the census would mean

fewer foreign born being categorized as legal immigrants and temporary migrants, and more foreign

born being categorized as residual foreign born during census level calculations.

Evaluation Question 2

Due to time constraints of the DAPE project, we assumed an average 15-percent undercount rate for

the residual foreign born, before meeting with external experts on international migration, even though

we expected rates to differ for all groups (legal immigrants and temporary migrants, as well as

the residual foreign born) and to vary by demographic characteristics (age, sex, race, and Hispanic origin)

and country of birth. Although no consensus emerged on the appropriate levels of undercount to
7

assume, experts we consulted agreed that the previously assumed average undercount of 15 percent

was probably too high, especially given the undercount rates of other hard-to-count groups from

Census 2000 (e.g., the undercount rate for Hispanic renters was less than 5 percent), (see Hogan and

Whitford, 2001). Additionally, a 15-percent undercount represented the midpoint of previously used

rates, but evaluation results suggest census coverage improved from the 1990 Census to Census 2000.

Evaluation Question 3

Most importantly, researchers were concerned about the possible implications of not correcting the

assumptions discussed above. Although an explanation that some legal immigrants and temporary

migrants were categorized as residual foreign born was helpful, the media and policy makers could

mistakenly interpret our results for the residual foreign born as a “best” guess of the size of the

unauthorized migrant population. Furthermore, because we had not included “quasi-legal” immigrants

(e.g., refugees who had not adjusted to legal permanent resident status because of processing backlogs

at INS) in the legal immigrant category, additional foreign born were included in this residual category. 

For a more detailed discussion of these populations, see Costanzo et al., 2001.

Based on these discussions, we decided to produce alternative undercount assumptions for the foreignborn population and to evaluate the initial, detailed set of estimates against the alternatives. In addition,

we are emphasizing that the residual group (as identified by our initial equation) is not an accurate

portrayal of the unauthorized foreign born. Finally, we identified additional information about the

foreign-born population to separate the residual foreign born category into two components: known

components of the foreign born (or those identified as quasi-legal) and the implied unauthorized

population (Costanzo et al., 2001; Deardorff and Cresce, 2001).

RESULTS OF ALTERNATIVE ASSUMPTIONS

Table 1 and Table 2 show estimates of the foreign-born population by migrant status using our baseline

estimates that assume a 15-percent undercount of the residual foreign born. For the remainder of this

report, we calculated the foreign-born population by migrant status using alternative assumptions about

census level coverage of these populations. In addition to using different coverage assumptions, we

attempt also to separate the residual foreign born into two components: known components (mostly

quasi-legal migrants) and the implied unauthorized migrant population.

To address our initial assumption about complete (100 percent) coverage of legal immigrants and

temporary migrants in the census, we estimated undercount rates for both groups, then applied those

undercount rates to the census level calculations. Although an endless number of possibilities existed

for alternative undercount scenarios, we attempted to create a lower and upper bound around our most

reasonable assumptions, which will be referred to as the “DAPE Estimate” in this report (Deardorff,

2001a).
8

Assumptions for the DAPE Estimate of the Foreign-Born Population

Beginning with a preliminary census level foreign-born population of 31,098,945, we assumed a 2-

percent undercount rate for legal immigrants, a 35-percent undercount rate for temporary migrants, a 5-

percent undercount rate for known components of the residual foreign born, and a 12.5-percent

undercount rate for implied unauthorized migrants (see Table 6 and Equation A). [Table 3 through

Table 5 show data with the underlying estimates of the foreign-born population by migrant status

consistent with the undercount rate assumptions shown in Table 6.]

For this scenario, the undercount rate of legal immigrants was assumed to be about twice as high as for

the total household population; the undercount rate of temporary migrants was calculated based on the

difference between the number we identified from our estimate (Cassidy and Pearson, 2001) and the

number of temporary migrants identified by INS, or 35 percent; the undercount rate of known

components of the residual foreign born was assumed to be about 4 times as high as for the total

household population (or slightly higher than the rate for Hispanic renters); and the undercount rate of

unauthorized migrants was assumed to be approximately 10 times the rate for the total household

population, or approximately 3 times the undercount rate for Hispanic renters (see Hogan and

Whitford, 2001).

Table 3 shows the resulting foreign-born population by migrant status.

Table 3: “True” Level Estimates of the Foreign-Born Population by Migrant Status in 2000: DAPE

Estimate 

Migrant Status Number

Foreign Born 33,091,988

 Survived Legal Immigrants 21,612,023

 Temporary Migrants 1,200,000

 Residual Foreign Born 10,279,965

 Known Components 1,789,474

 Unauthorized (Implied) 8,490,491

Assumptions for the DAPE Lower-Bound Estimate of the Foreign-Born Population

Beginning with a census level foreign-born population of 31,098,945, for the lower-bound estimate, we

assumed a 1-percent undercount rate for legal immigrants, a 7-percent undercount rate for temporary

migrants, a 1-percent undercount rate for known components of the residual foreign born, and a 10-

percent undercount rate for implied unauthorized migrants, as shown in Table 6 and Equation B. 

For this scenario, the undercount rate of legal immigrants was assumed to be about the same as for the

total household population; the undercount rate of temporary migrants was assumed to be almost twice
9

as high as for Hispanic renters; the undercount rate of known components of the residual foreign born

was assumed to be about the same as for the total household population; and the undercount rate of

unauthorized migrants was assumed to be approximately 8 times the rate for the total household

population, or a little more than twice the undercount rate for Hispanic renters (see Hogan and

Whitford, 2001).

Table 4 shows the resulting foreign-born population by migrant status.

Table 4: “True” Level Estimates of the Foreign-Born Population by Migrant Status in 2000: LowerBound DAPE Estimate

Migrant Status Number

Foreign Born 32,174,511

 Survived Legal Immigrants 21,612,023

 Temporary Migrants 1,200,000

 Residual Foreign Born 9,362,488

 Known Components 1,700,000

 Unauthorized (Implied) 7,662,488

Assumptions for the DAPE Upper-Bound Estimate of the Foreign-Born Population

Beginning with a census level foreign-born population of 31,098,945, for the upper-bound estimate, we

assumed a 2-percent undercount rate for legal immigrants, a 35-percent undercount rate for temporary

migrants, a 5-percent undercount rate for known components of the residual foreign born, and a 15-

percent undercount rate for implied unauthorized migrants (see Table 6 and Equation C). 

For this scenario, the undercount rate of legal immigrants was assumed to be about twice as high as for

the total household population; the undercount rate of temporary migrants was calculated based on the

difference between the number we identified from our estimate (Cassidy and Pearson, 2001) and the

number of temporary migrants identified by INS; the undercount rate of known components of the

residual foreign born was assumed to be about 4 times as high as for the total household population (or

slightly higher than the rate for Hispanic renters); and the undercount rate of unauthorized migrants was

assumed to be approximately 12 times the rate for the total household population, or nearly 4 times the

undercount rate for Hispanic renters (see Hogan and Whitford, 2001).
10

Table 5 shows the resulting foreign-born population by migrant status.

Table 5: “True” Level Estimates of the Foreign-Born Population by Migrant Status in 2000: UpperBound DAPE Estimate

Migrant Status Number

Foreign Born 33,347,473

 Survived Legal Immigrants 21,612,023

 Temporary Migrants 1,200,000

 Residual Foreign Born 10,535,450

 Known Components 1,700,000

 Unauthorized (Implied) 8,835,450

Implications and Reasonableness

The estimates of the foreign-born population differ because of alternative assumptions about coverage

rates by migrant status. The implied total undercount for the foreign-born population ranges from 3.3

percent using the assumptions for the lower bound to 6.7 percent using the assumptions for the upper

bound (see Table 6). These ranges are similar to the undercount rates (as measured by the A.C.E.) of

approximately 3 percent for Hispanics and approximately 4 percent for Hispanic renters.

Table 6: Census Level Undercoverage Rate Assumptions for the Foreign-Born Population by Migrant

Status: 2000

DAPE Estimate

Migrant Status Lower Bound "DAPE" Upper Bound

Foreign Born 32,174,511 33,091,988 33,347,473

 Survived Legal 1% 2% 2%

 Temporary 1 7% 35% 35%

 Residual Foreign Born

 Known Components 1% 5% 5%

 Unauthorized (Implied)2 10% 12.5% 15%

Average Undercount Rate3 3.3% 6.0% 6.7%

1 The 35-percent undercount assumption for temporary migrants is consistent with the Census Bureau’s estimate

using 1990 methodology. This methodology does not identify temporary migrants in certain visa categories that did

not exist until after 1990.

2 The undercount assumptions for unauthorized migrants are for “true” level, not census level.

3 Average undercount rate = ( (estimated foreign born - Census foreign born) / estimated foreign born) x 100. 

The Census foreign-born population was 31,098,945.
11

The “true” level for the foreign born would be 3.3 percent higher than census level using the

assumptions for the Lower-Bound DAPE Estimate; 6.0 percent higher using assumptions for the DAPE

Estimate; and 6.7 percent higher using assumptions for the Upper-Bound DAPE Estimate.

Using these new results for the total foreign-born population to calculate DA estimates results in figures

lower than the A.C.E. total population of 284,683,782 (see Table 7). Including the Lower-Bound

DAPE Estimate of the foreign born in the calculation of the DA population would result in an estimate

of 281,299,186, or more than 3 million people lower than the A.C.E. total population. The DA

population would be 282,216,664 using the DAPE Estimate for the foreign born, or more than 2 million

people lower than the A.C.E. total population. Similarly, the DA population would be 282,472,149

using the Upper-Bound DAPE Estimate for the foreign born, also more than 2 million lower than the

corresponding A.C.E. total population. In summary, despite the use of alternative assumptions in these

scenarios, resulting estimates of the foreign-born population do not explain the different total

populations calculated by DA and the A.C.E. 

Table 7: Effect of Alternative Assumptions for the Foreign-Born Population on Demographic Analysis

Estimates

“DAPE” Estimate

Component Lower Bound “DAPE” Upper Bound

DA Total Population 281,299,186 282,216,664 282,472,149

Foreign Born

 Number 32,174,511 33,091,988 33,347,473

 Percent 11.44 11.73 11.81

Implied Net Undercount of DA Total 

Population Relative to Census 2000

 Number -122,720 794,758 1,050,243

 Percent of DA Total -0.04 0.28 0.37

Notes: The Census 2000 Population is 281,421,906. A minus sign denotes a net overcount.
12

REFERENCES

Bean, Frank, Rodolfo V. Corona, Rodolfo Turain, Karen A. Woodrow-Lafield, and Jennifer V.W.

Van Hook. 2001. “Circular, Invisible, and Ambiguous Migrants: Components of Difference in

Estimates of the Number of Unauthorized Mexican Migrants in the United States.” Demography 38

(3): 411-22.

Cassidy, Rachel and Lucinda Pearson. 2001. Evaluating Components of International Migration:

Temporary (Legal) Migrants. (Population Division Working Paper #60) (December 2001) U.S.

Census Bureau.

Costanzo, Joseph, Cynthia Davis, Caribert Irazi, Daniel Goodkind, and Roberto Ramirez. 2001. 

Evaluating Components of International Migration: The Residual Foreign Born. (Population

Division Working Paper #61) (December 2001) U.S. Census Bureau.

Deardorff, Kevin. 2001a. “Alternative Assumptions for the Foreign-Born Population,” presentation

for the U.S. Census Bureau’s Executive Steering Committee for A.C.E. Policy.

Deardorff, Kevin. 2001b. “DAPE Evaluation of International Migration,” presentation for the U.S.

Census Bureau’s Executive Steering Committee for A.C.E. Policy.

Deardorff, Kevin and Arthur Cresce. 2001. “Alternative Assumptions for Components of International

Migration,” presentation for the U.S. Census Bureau’s Executive Steering Committee for A.C.E.

Policy.

Deardorff, Kevin and Nolan Malone. 2001. “Consistency of 2000 Nativity Data,” presentation for the

U.S. Census Bureau’s Executive Steering Committee for A.C.E. Policy.

Hogan, Howard and David Whitford. 2001. “Findings from the Census 2000 Accuracy and

Coverage Evaluation,” unpublished paper.

Malone, Nolan J. 2001. Evaluating Components of International Migration: Consistency of

2000 Nativity Data. (Population Division Working Paper #66) (December 2001) U.S. Census

Bureau.

Mulder, Tammany J., Betsy Guzman, and Angela Brittingham. 2001. Evaluating Components of

International Migration: Foreign-Born Emigrants. (Population Division Working Paper #62)

(December 2001) U.S. Census Bureau.

Passel, J.S. 2001. “Some Random Thoughts on Undocumented Immigration in Census 2000,

Demographic Analysis, A.C.E., and the CPS,” and “Comparison of Demographic Analysis, A.C.E.,

and Census 2000 Results by Race.” Unpublished memoranda.

Perry, Marc, Barbara van der Vate, Lea Auman, and Kathy Morris. 2001. Evaluating Components

of International Migration: Legal Migrants. (Population Division Working Paper #59) (December

2001) U.S. Census Bureau.

Robinson, J. Gregory. 2001. “Accuracy and Coverage Evaluation: Demographic Analysis Results,”

DSSD Census 2000 Procedures and Operations Memorandum Series B-4.
1The census level estimates used to produce results in Table 3 assumed a survived legal

immigrant population of 21,188,258 rather than 21,179,783. The “true” level estimates in Table 3

assumed known components of the residual foreign born were 1,789,474 rather than 1,700,000.

A-1

APPENDIX 1: EQUATIONS FOR DAPE

Equations for Estimating the Foreign-Born Population by Migrant Status

Equation A: DAPE Estimate of the Foreign-Born Population by Migrant Status1

Census Level Foreign Born = [L - (M + E)] + T + R1 + R2

“True” Level Foreign Born = ARL + ART + ARR1 + Implied Unauthorized

Counted L = 0.98 ARL

Counted T = 0.65 ART

Counted R1 = 0.95 ARR1

Census Level Foreign Born - (0.98 ARL) - (0.65 ART) - (0.95 ARR1) = 

Counted Unauthorized = R2

To get implied unauthorized:

Apply Undercount to Counted Unauthorized (R2) = 1/.875 R2

where:

[L - (M + E)] = Survived legal immigrants (counted)

 T = Temporary migrants (counted)

 R1 = Residual foreign born–known components (counted)

R2 = Residual foreign born–implied unauthorized (counted)

 ARL = Administrative record estimate of implied survived legal immigrants 

(INS data)

 ART = Administrative record estimate of temporary migrants (INS data)

 ARR = Administrative record estimate of residual foreign born known 

components (INS data)
2The census level estimates used to produce results in Table 4 assumed a survived legal

immigrant population of 21,398,043 rather than 21,395,903; a temporary migrant population of

1,121,495 rather than 1,116,000; and known components of the residual foreign born of 1,683,168

rather than 1,683,000.

A-2

Equation B: DAPE Lower-Bound Estimate of the Foreign-Born Population by Migrant Status2

Census Level Foreign Born = [L - (M + E)] + T + R1 + R2

“True” Level Foreign Born = ARL + ART + ARR1 + Implied Unauthorized

Counted L = 0.99 ARL

Counted T = 0.93 ART

Counted R1 = 0.99 ARR1

Census Level Foreign Born - (0.99 ARL) - (0.93 ART) - (0.99 ARR1) = 

Counted Unauthorized = R2

To get implied unauthorized:

Apply Undercount to Counted Unauthorized (R2) = 1/.90 R2

where the notation is as defined above.
3The census level estimates used to produce results in Table 5 assumed a survived legal

immigrant population of 21,188,258 rather than 21,179,783 and known components of the residual

foreign born of 1,619,048 rather than 1,615,000.

A-3

Equation C: DAPE Upper-Bound Estimate of the Foreign-Born Population by Migrant Status3

Census Level Foreign Born = [L - (M + E)] + T + R1 + R2

“True” Level Foreign Born = ARL + ART + ARR1 + Implied Unauthorized

Counted L = 0.98 ARL

Counted T = 0.65 ART

Counted R1 = 0.95 ARR1

Census Level Foreign Born - (0.98 ARL) - (0.65 ART) - (0.95 ARR1) = 

Counted Unauthorized = R2

To get implied unauthorized:

Apply Undercount to Counted Unauthorized (R2) = 1/.85 R2

where the notation is as defined above.
B-1

APPENDIX 2: DAPE WORKING PAPER SERIES BIBLIOGRAPHY

(in order of Working Paper Series Number)

Deardorff, K. and L. Blumerman. 2001. Evaluating Components of International Migration:

Estimates of the Foreign-Born Population by Migrant Status: 2000. (Population Division

Working Paper #58) (December 2001) U.S. Census Bureau.

Perry, M., B. Van der Vate, L. Auman, and K. Morris. 2001. Evaluating Components of

International Migration: Legal Migrants. (Population Division Working Paper #59)

(December 2001) U.S. Census Bureau.

Cassidy, R. and L. Pearson. 2001. Evaluating Components of International Migration:

Temporary (Legal) Migrants. (Population Division Working Paper #60) (December 2001)

U.S. Census Bureau.

Costanzo, J., C. Davis, C. Irazi, D. Goodkind, R. Ramirez. 2001. Evaluating Components of

International Migration: The Residual Foreign Born. (Population Division Working Paper

#61) (December 2001) U.S. Census Bureau.

Mulder, T., B. Guzmán, and A. Brittingham. 2001. Evaluating Components of International

Migration: Foreign-Born Emigrants. (Population Division Working Paper #62) (December

2001) U.S. Census Bureau.

Gibbs, J., G. Harper, M. Rubin, H. Shin. 2001. Evaluating Components of International

Migration: Native Emigrants. (Population Division Working Paper #63) (December 2001)

U.S. Census Bureau.

Christenson, M. 2001. Evaluating Components of International Migration: Migration Between

Puerto Rico and the United States. (Population Division Working Paper #64) (December

2001) U.S. Census Bureau.

Cresce, A., R. Ramirez, and G. Spencer. 2001. Evaluating Components of International

Migration: Quality of Foreign-Born and Hispanic Population Data. (Population Division

Working Paper #65) (December 2001) U.S. Census Bureau.

Malone, N. 2001. Evaluating Components of International Migration: Consistency of 2000

Nativity Data. (Population Division Working Paper #66) (December 2001) U.S. Census

Bureau.