Evaluating Components of International Migration: Foreign-Born Emigrants

____________________________________________________

Demographic Analysis-Population Estimates Research Project

Statement of Findings

Population Division Working Paper No. 62

April 15, 2002

Tammany J. Mulder

Betsy Guzmán

and Angela Brittingham

Population Division, U.S. Census Bureau

Department of Commerce

For presentation at the Population Association of America 2002 Annual Meeting, May 11,

Atlanta, Georgia.

* This paper reports the results of research and analysis undertaken by Census Bureau staff. It

has undergone a more limited review than official Census Bureau publications. This report is

released to inform interested parties of research and to encourage discussion. Please direct

questions to Tammany Mulder at (301) 763-6137 (tammany.mulder@census.gov).
1

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 estimate of foreign-born

emigration from the United States between 1980 and 1990. Estimates produced by Ahmed and

Robinson (1994) and Oosse (1998) were recreated and evaluated by age, sex, race, and Hispanic

origin to determine if the estimated flows were realistic. In addition, an attempt was made to

create new foreign-born emigration estimates for the 1990 and 2000 decade using the

preliminary results from Census 2000. Based on recreation and evaluation efforts, Ahmed and

Robinson and Oosse estimates appear sound and represent the most recent and most reliable data

on foreign-born emigration available. Future research is needed to evaluate the application of a

residual method to estimate foreign-born emigration. In addition, efforts will focus on creating

new estimates using alternative methodologies and data sources.
2

A. TABLE OF CONTENTS

B. INTRODUCTION AND BACKGROUND

What is emigration?

Emigration Estimates of the U.S. Legal Resident Foreign-born Population

Evaluation of Census Bureau Foreign-born Emigration Estimates

C. METHODOLOGY AND REPLICATION

Evaluation and Replication of Ahmed and Robinson Estimates

Evaluation of Oosse Estimates

Creation of New 1990-2000 Foreign-born Emigration Estimates 

D. LIMITATIONS

Ahmed and Robinson Estimates

Oosse Estimates

E. RESULTS

Replication of Ahmed and Robinson Estimates

Evaluation of Oosse Estimates

Creation of New 1990-2000 Estimates

Is the assumed flow of foreign-born emigration realistic?

F. REFERENCES

G. TABLES AND APPENDICES

Appendix A. Description of the SAS programs used to replicate Ahmed and Robinson’s 1980-1990

emigration estimates.

Appendix B. Categorical age variables used to replicate Ahmed and Robinson’s 1980-1990 emigration

estimates.

Appendix C. Country of birth variables used to replicate Ahmed and Robinson’s 1980-1990

emigration estimates.

Appendix D. Demographic Analysis–Population Estimates (DAPE) Research Projects Related to

Evaluating Components of International Migration.

Table 1. The number of immigrants and foreign-born emigrants by decade: 1900-1989.

Table 2. Foreign-born emigrants for the national estimates: 1990-2000.

Table 3. Ahmed and Robinson categorization of selected and non-selected countries and race and

Hispanic origin by country of birth.

Table 4. 1980-1990 foreign-born emigration as estimated by Ahmed and Robinson and DAPE, and the

difference between the two, by selected and non-selected countries, race groups, and sex.

Table 5. 1980-1990 average annual foreign-born emigration as estimated by Oosse and DAPE, by

country of birth and sex.
3

B. INTRODUCTION AND BACKGROUND

What is emigration?

International migration consists of flows both to and from a host country. Emigration, the

departure from a country of residence, is a component of net international migration. As a

component of change in population estimates for the United States, emigration is defined as the

number of U.S. residents departing permanently from the U.S. to reside abroad. This movement

is one of the most problematic components of international migration to estimate and is

estimated separately for the native and foreign-born portions of the resident population.

Theoretically, estimates of the emigrant population should not include unauthorized or temporary

migrants leaving the United States because these populations are estimated as a separate

component of net international migration.

Emigration Estimates of the U.S. Legal Resident Foreign-Born Population

The Immigration and Naturalization Service (INS) began collecting data on the emigration of the

United States population in 1901. Attempts to collect data on emigrants were terminated in 1957

due to the questionable reliability (Warren and Peck 1980). After INS discontinued this data

series, the Census Bureau began producing estimates of emigration as a component of estimated

net international migration used in the production of the demographic analysis estimates of the

census population adjusted for estimated net census undercount and of intercensal and postcensal

national population estimates. The following discussion provides an overview of the major

emigration estimates produced since the direct method of data collection was discontinued.
4

Warren and Peck (1980) produced foreign-born emigration estimates for the 1960 to 1970

decade using a residual methodology. The method used data for the foreign-born population

from two consecutive decennial censuses and the number of immigrants admitted between the

respective censuses. In summary, the expected foreign-born population as of the 1970 census

date was calculated from the enumerated foreign born in the 1960 census and the number of

immigrants admitted during the intercensal period, using a cohort-survival methodology to

account for mortality during the ten year period between censuses. The expected foreign-born

population in 1970 was subtracted from the 1970 enumerated foreign-born population, resulting

in an estimate of the number of foreign-born emigrants for the decade. According to Warren and

Peck, approximately 1.14 million foreign-born residents left the United States from 1960 to 1970

when controlling for nonimmigrant students. Inclusion of non-immigrant students increased the

estimate from 1.14 million to 1.18 million people.

New estimates for the 1960 to 1970 and 1970 to 1980 period were produced by Warren and

Passel as an input to estimate the undocumented migrant population (Warren and Kraly 1985).

Estimates were derived by applying a cohort-component method using INS annual registration

data and the components of population change to estimate the emigration of the “non-U.S.

citizen” (p. 16). The non-U.S. citizen population excludes the naturalized foreign-born

population. Table 1 presents Warren and Passel’s results for both decades. For the 1960 to 1970

decade, Warren and Passel estimated 900,000 non-citizen foreign-born emigrants, which is

smaller than Warren and Peck’s estimate of 1.14 million total foreign-born emigrants. For the

1970 to 1980 decade, the number of non-citizen emigrants increased from 900,000 to 1.18

million.
5

Borjas and Bratsberg (1996) also produced foreign-born emigration estimates for the 1970 to

1980 decade, concentrating only on the legal immigrant population. INS microdata pertaining to

aliens granted legal permanent residence were compared to the 1980 census results for those who

entered between 1970 and 1980 after adjusting for mortality. The authors isolated the legal

immigrant population by adjusting the 1980 census, removing illegal immigrants and

nonimmigrants. According to Borjas and Bratsberg, among legal immigrants that entered

between 1970 and 1974 and 1975 and 1980, approximately 21.5 percent and 17.5 percent

respectively emigrated by 1980. The total number of legal foreign-born emigrants for the decade

was estimated to reach 882,483 people. This estimate is smaller than the non-citizen estimate of

1.18 million by approximately 298,000 people.

Emigration estimates for 1980 to 1990 were produced by Ahmed and Robinson (1994). Similar

to Warren and Peck, Ahmed and Robinson applied a residual methodology to estimate the

number of emigrants and the emigration rates for the foreign-born population that entered before

1980. These estimated rates were then applied to the 1990 enumerated population to estimate

emigration from 1980 to 1990. This methodology produced an estimate of 195,000 annual

foreign-born emigrants for the April 1, 1980 to April 1, 1990 period. In other words,

approximately 1.95 million foreign-born people emigrated in the ten-year period. The number of

estimated emigrants represents approximately 25 percent of the immigrants who were granted

legal permanent residence by the INS between 1980 and 1990 (Table 1). Compared with

estimates for previous decades, Ahmed and Robinson’s estimates indicate a sizable increase in

estimated emigration; however, as shown in Table 1, the ratio of emigrants to the number of

immigrants declined from .27 to .25 from 1970-1979 to 1980-1989.
6

According to data presented by Warren and Kraly (1985) in Table 1, the number of emigrants

historically remained a consistent proportion of the legal immigrant population for particular

decades. The number of emigrants from 1900 to 1979 represented approximately one-third of

the number of legal immigrants. With exception to the 1950-1959 decade, the ratio of the

number of emigrants to the number of immigrants for decades in the 1940-1989 period ranged

from .25 to .33. For the 1900 to 1989 period, the ratio of foreign-born emigrants to legal

immigrants was .32. As the number of immigrants increased or decreased, so too did the number

of emigrants. According to Duleep (1994),

.... emigration is highly concentrated in the initial years of U.S. residence. A

majority of the immigrants who emigrate do so within 5 years of U.S. residence,

and about 80 percent or more emigrate within the first 10 years. Only 13 to 20

percent of the immigrants who emigrate appear to do so after 10 years (p. 45).

In summary, emigration usually takes place within a few years after the year of immigration.

Therefore, in all likelihood, trends in emigration will reflect trends in immigration with a time

lag.

In order to improve estimates of emigration trends for the foreign-born population in the national

population estimates, Oosse (1998) revised the foreign-born emigration estimates by creating

emigration rates to be applied to the U.S. legal resident foreign-born population. The rates

represent new emigration estimates based on the emigration estimates produced by Ahmed and

Robinson. Application of annual emigration rates to the foreign-born population theoretically

reflects annual emigration trends as the foreign-born population changes each year, compared to
7

applying a constant annual assumption of a number of emigrants each year. Table 2 presents the

foreign-born emigration estimates for April 1, 1990 to April 1, 2000, based on the application of

Oosse’s emigration rate estimates. The number of foreign-born emigrants totaled 2.17 million

for 1990 to 2000, or 26 percent of the estimated legal immigrant and refugee population for the

same period (not shown).1 The average annual number of emigrants for the decade was

approximately 217,000.

Woodrow-Lafield (1996) produced an alternate estimate of the emigrant population as of 1990

using a multiplicity survey methodology. Estimates were created for Americans Living Abroad

(ALA’s) and emigrants and emigration estimates do not differentiate between native and foreignborn status. According to Woodrow-Lafield,

For the period 1980-1989 (or 1980-1988), the implied number of emigrants would

be 1.2 million. Prorating to annual average figures, emigration during the 1980s

may have ranged between 110,000 and 200,000, considering likely sampling

errors. Lower coverage levels of the emigrant population would imply a higher

emigrant population, perhaps exceeding three million, and higher levels of annual

emigration (p. 191-192).

In comparison to the multiplicity survey results after considering nativity status and coverage

levels, the Ahmed and Robinson estimate of 195,000 annual foreign-born emigrants falls within

the 110,000 to 200,000 range. The Oosse estimate of 217,000 is slightly above the stated range.

 

1

The legal immigrant and refugee estimates are published in Population Division Working Paper #51

(2001).
8

The multiplicity estimates are based on survey results and the emigrant population is generally

small in size. Hence, the estimates are prone to sampling error (p. 175), preventing the

estimation of general demographic characteristics, such as the age and sex of emigrants.

Therefore, multiplicity survey results contribute to the knowledge of the aggregate number of

emigrants, but do not represent a viable estimate to apply to the national estimates and

demographic analysis estimates products.

In summary, only a small amount of research exists on estimating the U.S. foreign-born emigrant

population. In general, when creating estimates, the use of direct techniques are preferred over

indirect techniques and theoretically produce estimates that are more reliable. However,

estimates produced using direct methods, more specifically using data collected by the INS, for

the first half of the century (1901-1957) are questionable as noted by Warren and Peck. As of

1957, emigration estimates used for national estimates were produced using an indirect

methodology. For the most part, foreign-born emigration estimates were produced using a

derivative of a residual methodology. In conclusion, little is known about the actual level of U.S.

emigration, making it one of the most difficult components of net international migration to

estimate. However, estimates produced by Ahmed and Robinson and by Oosse represent the

most recent detailed emigration estimates available. In addition, the estimates appear to follow

historical emigration trends and approximate estimates produced using different data sources and

methodology.
9

Evaluation of Census Bureau Foreign-born Emigration Estimates

To help evaluate the Demographic Analysis and the national population estimates, Task Team 6

was directed to answer the following research question: “Is the assumed flow of foreign-born

emigration realistic?” The team was asked to, “Replicate/create tabulations of the foreign born

in 1990 to evaluate current assumptions by age, sex, race, and Hispanic origin (US Census

Bureau P. 5).” In addition to 1980-1990 estimates, Team 6 was directed to create new foreignborn emigration estimates for the 1990 and 2000 decade using the preliminary results for census

2000.

This statement of findings presents 1) the methodology used to answer the above stated research

question and the replication efforts, 2) the limitations discovered throughout the replication

process, 3) the results of the replication efforts compared to the original estimates produced by

Ahmed and Robinson and by Oosse, and 4) a discussion of new 1990-2000 foreign-born

emigration estimates.

C. METHODOLOGY AND REPLICATION

Evaluation and Replication of Ahmed and Robinson Estimates

As discussed above, Ahmed and Robinson applied a residual technique to create emigration

estimates based on the 1980 and 1990 censuses. The residual technique is a general tool

developed to compare an expected population at a specific point in time to an enumerated

population at the same point in time in order to isolate a population of interest. In the case of

emigration, this translates as applying a cohort-survival method to the foreign-born population

enumerated in an earlier census and comparing that expected population to the corresponding
10

population enumerated in a latter census. Theoretically, the difference should be the population

that emigrated between the two censuses.

In order to produce the 1990 emigration estimates, Ahmed and Robinson (p. 2) summarized the

methodology with the following equations:

E1980-1990 = (P1980 – D1980-1990) – P1990

or, E1980-1990 = S1990 – P1990

where 

E1980-1990 is the estimated number of foreign born who emigrated between 1980

and 1990

P1980 is the foreign-born population enumerated in the 1980 census

D1980-1990 is the number of deaths experienced from 1980 to 1990 by the foreignborn population enumerated in 1980

P1990 is the foreign-born population that entered before 1980 and was enumerated

in 1990

S1990 is the 1980 foreign-born population survived to 1990

The above methodology produces a stock number of emigrants and the emigration rates for the

10-year period (1980 to 1990) for the foreign-born population that entered before 1980. This

method does not apply to the foreign-born population that entered between 1980 and 1990.

Therefore, the emigration rates calculated for the before 1980 entrants, adjusted for the average

length of stay and mortality, were applied to the foreign-born population enumerated in the 1990

census that entered between 1980 and 1990. A detailed discussion of the methodology is

included below in the discussion of the replication efforts of Ahmed and Robinson’s estimates.

To replicate the estimates produced by Ahmed and Robinson, we began by locating all existing

papers, programs, and results found internally at the Census Bureau. This included obtaining

original SAS programs written by Ahmed, input and output data, spreadsheets created by
11

Ahmed, life tables tabulated by the Projections Branch, internal Census Bureau memorandums

and notes, and working papers published in the Population Division working paper series. Once

all the available information was gathered, we began replication of the estimates by following

Ahmed and Robinson’s methodology, piecing together programs and data sets. A majority of the

replication efforts resulted in creating new programs.

Appendix Apresents a detailed outline of the steps used to replicate the estimates based on SAS

programs, those existing prior to replication efforts and those developed during the process. The

main steps are listed below in order with a reference to the detailed step number from Appendix

A in parenthesis. These steps do not represent the actual order of steps taken by Ahmed and

Robinson.

1) Preliminary emigration estimates for the population that entered before 1980.

(Step 3)

2) Emigration estimates for the population that entered before 1980 for selected

countries. (Step 4)

3) Emigration estimates for the population that entered between 1980 and 1990 for

selected countries. (Step 6)

4) Emigration estimates for the population that entered between 1980 and 1990 for

non-selected countries. (Step 8)

5) Emigration estimates for the population that entered before 1980 for non-selected

countries. (Step 10)

6) Final estimates of emigration for the 1980-1990 decade. (Step 11)
12

1) Preliminary emigration estimates for population that entered before 1980

To begin, preliminary estimates of the emigrant population were created for the foreign-born

population that entered before 1980. Data used to create the estimates were the 1980 census of

the resident foreign-born population as of April 1, the 1990 census of the resident foreign-born

population as of April 1, and 10 year survival rates calculated from 1990 life tables generated by

the Population Projections Branch of the US Census Bureau. The 1980 census data were used to

calculate the 1990 expected population, and the 1990 census was used as the enumerated

population to compare the expected population. Survival rates were used to age the 1980

population 10 years to create the expected 1990 population.

The 1980 census results were available from a summary file previously adjusted for unknown

country of birth. Characteristics include sex, age collapsed to 14 categories (see Appendix B),

country of birth by 40 country groups (see Appendix C), citizenship status, and period of entry

collapsed to 1975-1980, 1970-1974, 1960-1969, and before 1960. The methodology used to

impute unknown country of birth for this file was not determined. During the estimates

procedure it was discovered that the 1980 file contained people placed in incorrect age groups

with respect to their period of entry. In all likelihood, this error occurred in the census editing

procedure when imputing unknown characteristics of respondents. These cases were removed

from the data set.

Data for 1990 were generated from the 1990 census (Summary Tape File 3 – Sample Data) and

recoded for estimates purposes. Characteristics of the foreign-born population include sex, age

collapsed to five-year age groups, race and Hispanic origin, country of birth by 111 country

groups (see Appendix C), citizenship status, and period of entry collapsed to 1987-1990, 1985-
13

1986, 1982-1984, 1980-1981, 1975-1979, 1970-1974, 1960-1969, and before 1960. Originally,

the 1990 country of birth coding contained an additional code for those enumerated as being

born abroad, at sea, and not specified, but this population was proportionally distributed prior to

the emigration processing.

In order to produce reliable estimates using a large enough data set to provide “stability of the

rates” (p. 4), Ahmed re-classified both the 1980 and 1990 census country of birth codes from 40

country groups into categories of four country groups, each theorized to represent the following

race and ethnic groups: Hispanic, non-Hispanic White, Black, and Asian and Pacific Islander.

Table 3 presents the list of countries used to create each mutually exclusive race and Hispanic

origin group. The classification for each country was based on the reporting of race and

Hispanic origin and country of birth of the foreign-born population in the 1990 census. We were

unable to replicate this task due to time constraints. Although the race and origin groups are

actually country groups and are not the census reported race and origin values, they are referred

to hereafter as race groups to prevent confusion.

Survival rates were needed to obtain the 1990 expected population. National resident population

life tables for 1990, generated by the Population Projections Branch, were used to calculate the

ten-year survival rates needed to survive the 1980 foreign-born population of before 1980

entrants. Life tables were available for four race groups (White, Black, American Indian,

Eskimo and Aleut, and Asian and Pacific Islander) by Hispanic and non-Hispanic origin, and for

Hispanic origin only. To calculate survival rates by sex, age groups, and the four race groups

based on country groups, Ahmed and Robinson used the non-Hispanic White, Hispanic only,

Black, and Asian and Pacific Islander life tables. The Black and Asian and Pacific Islander life
14

tables were generated for both the Hispanic and non-Hispanic population. See Ahmed and

Robinson for survival rates (1994, p. 30).

Once the data sets were acquired and recoded, Ahmed and Robinson calculated a preliminary

residual estimate of 1980-1990 emigrants for the population that entered before 1980. The

expected foreign-born population for 1990 was calculated by surviving the 1980 enumerated

foreign-born population by sex, age, race group, and period of entry. The difference between the

expected 1990 population that entered before 1980 and the enumerated 1990 population for those

entering before 1980 is the estimated number of emigrants who left between 1980 and 1990.

Estimates were created by age, sex, country of birth groups (40), and period of entry. Emigrants

for each of the 40 countries were maintained in the estimate process, irrespective of race group

designation. See Ahmed and Robinson for the preliminary residual results (1994, p. 17).

Ideally, the residual would provide the total number of emigrants for each country as a positive

number. The preliminary residual, however, resulted in negative differences for the aggregate

value for particular countries. After conducting background research into why particular

countries obtained negative values, Ahmed and Robinson separated the countries into selected

and non-selected countries. The non-selected countries were those countries that showed a

statistically significant negative difference. We were unable to locate or replicate the statistical

tests conducted for the negative differences. Non-selected countries were Mexico, El Salvador,

Guatemala, Peru, Haiti, Jamaica, Trinidad and Tobago, and Other South and East Asia. In

addition, the selected and non-selected countries were then separated into the corresponding race

groups previously assigned.
15

In summary, the data set was divided into two separate groups, the non-selected and selected

countries. Both country groups are available by the four race groups, age groups, sex, country of

birth, and period of entry. None of the non-selected countries fell into the non-Hispanic White

race group.

2) Emigration estimates for the population that entered before 1980 for selected countries

After categorizing the data into the selected and non-selected countries, estimates were derived

of the number of emigrants and the emigration rate for selected countries only by age, sex, race

group, country of birth, and period of entry. Emigration estimates were derived for 1970-1979,

1960-1969, and before 1960. The 1990 expected population for before 1980 entrants was

compared to the observed population enumerated in 1990 that entered before 1980. Negative

differences were still obtained for countries within the age, sex, and race group distributions, but

not for the aggregate number of emigrants. The negative cases were removed from the data set.

Based on the steps listed above, we replicated Ahmed’s results of the 1980-1990 number of

emigrants and the emigration rate for before 1980 entrants for selected countries by age, sex, and

race.

3) Emigration estimates for the population that entered between 1980 and 1990 for selected

countries

Next, the number of emigrants and the emigration rate for selected countries were calculated for

the population that entered between 1980 and 1990. Estimates for the 1980-1990 period of entry

were not estimated using the residual methodology as was done for before 1980 entrants. In

comparison, an emigration rate for 1980-1990 entrants was estimated and applied to the 1990

enumerated population that entered within the same period.
16

To begin, the foreign-born population enumerated in the 1990 census that entered between 1980

and 1990 by age, sex, and country of birth was isolated. The race groups were coded and the

non-selected countries were removed. The period of entry for the 1990 census was collected in

four categories (1987-1990, 1985-1986, 1982-1984, and 1980-1981). The following steps were

taken to produce the 1980-1990 selected country emigration estimates:

a. The proportion of 1980-1990 foreign-born entrant population enumerated in the

1990 census were calculated by age, sex, period of entry, and race.

b. The average length of stay for 1980-1990 was determined for each age group.

The proportions of foreign born in each period of entry and age group by sex and

race were multiplied by the average potential number of years an immigrant could

reside in the U.S. based on period of entry. The proportions for 1987-1990

entrants were multiplied by 1.63 years, 1985-1986 by 4.25 years, 1982-1984 by

6.75 years, and 1980-1981 by 9.25 years. Ahmed and Robinson define the

average length of stay as, “... the weighted average of the duration to April 1,

1990 from the middle points of the years 1980-1981, 1982-1984, 1985-1986, and

1987-1990 (p. 8).”

c. The mid-point of age in 1990 was determined by calculating the middle age value

within an age group. For example, the middle age value for the 0-4 year age

group (i.e., 0 to exact age 5) is 2.5 years.
17

d. Average age at time of entry was then calculated by subtracting the average length

of stay from the mid-point of age in 1990.

e. To calculate 1980-1990 entrant emigration rates, the 1970-1979 entrant

emigration rates were used as a base. Taken from Step 2 for selected countries,

the 1970-1979 rate’s age distribution was expanded from 13 to 15 categories to

match the 1990 age groups and the ten-year rates were annualized.

f. The 1970-1979 entrant emigration rates were multiplied by the average length of

stay to weight the rates for the number of years migrants are able to emigrate.

g. Survival rates were subtracted from the adjusted 1970-1979 entrant emigration

rates to account for mortality. Rates were estimated by sex, age, and race using

the 1990 life tables referenced above, based on the age at the time of entry and the

length of stay.

h. Estimates of the theoretical number of 1980-1990 entrants were derived by

dividing the enumerated 1990 foreign-born population that entered between 1980

and 1990 by the adjusted 1970-1979 emigration rates to include the population

subject to mortality by age, sex, and race.

i. The theoretical number of 1980-1990 entrants was multiplied by the adjusted

1970-1979 emigration rate. This step produced estimates of the number of
18

emigrants for selected country 1980-1990 entrants by age, sex, race group, and

country of birth.

4) Emigration estimates for the population that entered between 1980 and 1990 for nonselected countries

Emigration estimates for the selected countries for before 1980 and 1980-1990 entrants were

produced in Step 2 and Step 3. In the next two steps, non-selected country emigrants and the

emigration rates were calculated separately for both the before-1980 and 1980-1990 entrants.

As described above, non-selected countries were coded as the countries with statistically

significant negative number of emigrants calculated in Step 1. Based on research presented in

their paper, Ahmed and Robinson assumed that these countries were likely to have lower rates of

emigration than the selected countries. Various percentages were tested before arriving at the

conclusion that halving the emigration rate from the selected countries would be the most

reasonable assumption. Non-selected 1980-1990 entrant emigration rates were calculated by

multiplying the adjusted 1970-1979 emigration rates, calculated in Step 3, by .5.

Once the 1980-1990 non-selected emigration rates were calculated, the steps taken in Step 3

were duplicated for the non-selected countries. The 1990 ten-year survival rates by sex, age, and

race were subtracted from the non-selected 1980-1990 emigration rates to account for mortality.

The theoretical number of 1980-1990 entrants were estimated by dividing the enumerated 1990

foreign-born population by the 1980-1990 non-selected emigration rates adjusted for mortality.
19

5) Emigration estimates for the population that entered before 1980 for non-selected

countries

To estimate the number of emigrants for those who entered before 1980 for non-selected

countries, the same steps were taken as in Step 2 with exception to differing emigration rates.

The emigration rates produced in Step 2 for selected countries were halved and applied to the

non-selected countries by age, sex, race groups, and period of entry (1970-1979, 1960-1969,

before 1960).

6) Final estimates of emigration for the 1980-1990 decade

Estimates for the before 1980 and 1980-1990 entrants for selected and non-selected countries

were aggregated, maintaining the age, sex, race, period of entry, and selected/non-selected

country characteristics.

Evaluation of Oosse Estimates

Time limitations permitted only a detailed analysis of the estimates produced by Oosse, as

opposed to a complete validation effort. Therefore, only the methodology used to create the

estimates will be discussed. Oosse used Quattro Pro spreadsheets to create the final 1980-1990

emigration rates.

As mentioned above, Oosse’s estimates were created to update the emigration assumption for the

processing of the national estimates and the demographic analysis estimates. Historically, a

constant number of emigrants was used as input into the estimated net international migration

component. Emigration rates for the foreign-born population allowed demographers to vary

emigration estimates as the size and composition of the foreign-born population changed from
20

year to year. In addition, the new estimates were expanded to single year of age from 0 to 115

years of age and 14 country groups. The following are the general steps taken to produce the

revised set of estimates.

1) Produced new emigration estimates for 1980 to 1990 based on Ahmed and Robinson’s

estimates.

In order to produce updated estimates based on the Ahmed and Robinson estimates, we collected

the 1980 and 1990 census foreign-born results, survival rates calculated by Ahmed and

Robinson, and emigration data supplied by Ahmed.

a. To begin, Oosse calculated the expected 1990 foreign-born population by

applying 10-year survival rates to the 1980 foreign-born population by age, sex,

country of birth (40), and period of entry. The population was aggregated by

country of birth and sex for analysis purposes.

b. Oosse then calculated an average 1980 foreign-born population by age, sex,

period of entry, and country of birth by calculating the average of the 1980 census

of the foreign born and the expected 1990 foreign-born population calculated in

Step (a) above.

c. Emigration rates estimated by Ahmed and Robinson for the pre-1980 periods of

entry are applied to the average 1980 foreign-born population, resulting in

estimates of the average annual number of emigrants for the before 1980 entrants
21

by age, sex, country of birth (40), period of entry, and selected/non-selected

county status.

d. After calculating the average annual before 1980 entrant emigration estimates,

Oosse calculated the annual number of emigrants for the 1980-1990 period of

entry. The 1990 census file was recoded for unknown country of birth for 1980-

1990 entrants using a proportional distribution based on the country of birth

distribution reported by Ahmed and Robinson. The adjusted 1980-1990 entrant

emigration rate estimates produced by Ahmed and Robinson were applied to the

1980-1990 enumerated foreign-born population. These calculations resulted in

the 1980-1990 annual number of emigrants by age, sex, and country of birth (40)

for 1980-1990 entrants.

e. New estimated 1980-1990 annual number of emigrants was calculated by

summing across each period of entry by age, sex, country of birth, and

selected/non-selected country status.

f. Oosse compared the new annual emigration estimates to Ahmed and Robinson’s

final estimates. Based on this comparison, Oosse calculated sex and country of

birth-specific rake factors that were applied to the new annual emigrant estimates

to replicate the distribution of the 40 countries of birth distribution originally

estimated by Ahmed and Robinson. These calculations produced an estimate of

the annual number of emigrants for 1980 to 1990 by age, sex, and country of

birth.
22

g. The average 1985 foreign-born population was calculated by averaging the 1980

and 1990 enumerated foreign-born population by age, sex, and country of birth.

The theoretical number of unauthorized migrants in the base population was

removed by applying a proportion of the unauthorized population to each country.

Adjustments were made to 13 countries. Table 5 presents a list of the 13

countries.

h. 1980 to 1990 annual emigration rates were calculated by dividing the estimated

annual number of emigrants for 1980 to 1990 calculated in Step (f) by the average

1985 foreign-born population calculated in Step (g). The rates were calculated by

sex, age groups, and country of birth (40). Rates for Cuba were assumed to be

zero.

2) Created estimates of the annual number of emigrants for 1980 to 1990 and the respective

rates in greater demographic detail.

Application of emigration estimates to the net international migration component required the

adjustment of the 1980-1990 emigration estimates. The age distributions for the estimated

number of emigrants and the average 1985 population were expanded to single year of age from

0 to 115 years and the country of birth groups collapsed from 40 to 14 groups. The age

distribution was disaggregated by proportionally distributing the total number within each age

group for both the five-year and ten-year groups. For emigrants and the 1985 average population

in the 75 years and older category, the number is expanded to single year of age based on

proportions in a 1989-1991 stable population life table published by NCHS.
23

For Demographic Analysis-Population Estimates (DAPE) research project replication purposes,

we maintained the original 40 countries of birth distribution to allocate race and Hispanic origin

characteristics. The imputations were created based on the results of the 1990 census. In

conclusion, the estimated number of annual emigrants for 1980-1990, the respective emigration

rates, and the average 1985 population by sex, single year of age (0-115), race, Hispanic origin,

and country of birth were distributed internally to be used in the production of estimates by other

DAPE task teams.

Creation of New 1990-2000 Foreign-born Emigration Estimates

In addition to replicating and analyzing the existing foreign-born emigration estimates, Task

Team 6 endeavored to create new estimates for the 1990 to 2000 decade. Following the

guidelines set forth by the DAPE Core Team and recognizing the existing time limitations, we

adopted the methodology used by Ahmed and Robinson and attempted to produce 1990-2000

foreign-born emigration estimates by single year of age, sex, race, Hispanic origin, country of

birth, and period of entry.
24

The methodology used previously was altered because additional data and research to support

alternative methodological assumptions were available. Similar to Ahmed and Robinson, we

began with the 1990 and 2000 enumerated foreign-born population from the census sample files.

Survival rates were generated using 1999 life tables generated by the Population Projections

Branch of the US Census Bureau.

The census population universe is the total resident population, which includes both the

unauthorized and temporary migrant populations. Because we are estimating the emigration of

the legal permanent resident foreign-born population only, the presence of these populations in

the universe creates biases in the estimates. In comparison to the 1980-1990 methodology, we

were able to isolate the temporary migrant population present in the population universe using

the temporary migrant estimates produced by Task Team 8 for 1990 and 2000. Unauthorized

migration estimates for 1990 and 2000, however, were created as part of the emigration estimates

production process based on existing research (Passel 1999).

Estimates produced by Ahmed and Robinson used four race groups and applied race-Hispanic

origin-based survival rates. For the 1990-2000 estimates, a race variable based on country of

birth was not created. The 1990 Census race and Hispanic origin variables were used, which

were proportionally distributed for Census 2000 based on reported age, sex, and country of birth

in both the 1990 and 2000 census. Survival rates were calculated from life tables of the total

population by sex and single year of age.
25

Once the unauthorized and temporary migrant populations were removed from the 1990 and

2000 foreign-born populations, we generated a preliminary estimate of the before 1990 entrant

emigrants as was estimated by Ahmed and Robinson in Step 1 (above) for the before-1980

entrants. New estimates were generated by single year of age with no race detail.

Preliminary residual estimates produced several countries with negative results. The negative

results may originate from overestimating mortality, erroneous assumptions about the

unauthorized or temporary migrant population, and changes in census coverage of the foreignborn population between censuses. In all likelihood, the enumeration of the foreign-born

population in 2000 improved over the 1990 census. Therefore, the foreign-born population for

those who entered before 1990 could be larger in 2000 than is theoretically possible based on the

results of the 1990 census. In addition, respondents may provide erroneous responses to the

period of entry on the census.

Time limitations prevented the completion of 1990-2000 based estimates. Based on the presence

of large negative values for several countries, it is necessary to revisit the original methodology

and assumptions used to create the estimates.

D. LIMITATIONS

Limitations arose from the lack of research in the field of emigration. There is little knowledge

about the characteristics and flow of foreign-born emigrants. Without a better understanding of

the population of interest, it is difficult to evaluate the adequacies of the methodology. For

example, the residual methodology does not account for the changes in the foreign-born
26

population due to changes in the unauthorized population or in the temporary migrant

population. In addition, the assumption of complete coverage of the foreign-born population in

the 1980 and 1990 census, inherent to Ahmed and Robinson’s and to Oosse’s estimates, is in all

likelihood incorrect.

The most severe constraint for the DAPE project was the time frame within which we were

expected to undertake the project. After each estimate was validated, there was insufficient time

to check the quality or to examine the reasonableness of the estimates. Because there were many

problems fitting the data and the methodology, the 1990-2000 estimates were not finished and

the 1980-1990 estimates had to be used for the 1990-2000 period. The emphasis was placed on

replicating the existing estimates and creating new estimates within the allotted time frame.

Ahmed and Robinson Estimates

Limitations to Methodology

Replication efforts did not include an evaluation of the methodology, therefore the

appropriateness of the residual methodology is taken as a given. However, there are still

limitations to the methodology that can be divided into two general areas: problems with the

assumptions and inconsistencies between the theory underlying the calculations, and the actual

trends.

The residual method assumes there is no difference in coverage rates between the censuses.

However, evidence suggests that Census 2000 had better coverage than the 1990 Census. The

change in coverage would contribute to the fact that many more foreign-born were enumerated in
27

2000 than would have been expected given the population in 1990. Therefore, coverage error

may bias the 1980 to 1990 emigration estimates. However, we were unable to research this

possibility in depth.

In addition to assuming that the coverage is the same between the two data points, we assume

that there is no significant difference between population universes of the two sources. Two

populations that challenge this assumption are the unauthorized population and the temporary

migrant population. Although one could argue that the effects could cancel each other out if the

numbers were incorrect in both time points, the presence of negative results indicates that it is a

problem. In particular, the negative results are prevalent in countries that are most likely to be

sending countries for unauthorized migrants. The methodology, as described by Ahmed and

Robinson, makes allowances for this discrepancy by halving the emigration rate of those country

groups that do not have negative effects. Additional research needs to be done to investigate

whether or not there is a better way to account for the negative results.

In order to calculate the expected population to compare to the enumerated population, we need

to make assumptions about the mortality trends of the foreign-born. Research in the field of

mortality indicates that the foreign-born population has better life expectancies, or higher

survival rates than the native population, which is not reflected in the mortality assumption used

to create the expected 1990 population (Crouch 2000). For the purposes of the methodology, the

life table schedules for the native populations used to create the mortality rates were applied to

the foreign-born population. This assumption is more accurate than using the life tables for the

sending countries because the foreign born who migrate also exhibit higher survival rates than

those who do not migrate. It is possible that the U.S.-based tables overestimate deaths to the
28

foreign-born population. If deaths were overestimated, the expected population would be too

small and could then be smaller than the enumerated population, leading to the negative results.

Because the methodology relies on the trends for the previous decade, the estimates for 1990 are

actually based on the rates for the foreign-born population that entered between 1970 and 1979.

We know that the international migration trends have been quite different from one decade to the

next so there is no reason to believe that emigration trends are static. Even if the emigration

trends were not as dynamic as immigration trends, there is not sufficient evidence to support

emigration estimates based on 1970 to 1979 trends for the 1980 to 1990 period.

The methodology also incorporates the underlying theoretical trend that ten-year trends are

representative of the actual annual trends. Because the method uses census data, the data are

collected ten years apart. We know from existing research that migration fluctuates throughout

the decade. If emigration closely follows immigration, then annualized ten-year trends do not

accurately reflect changes from year to year.

Limitations to Replication Effort

The ability to replicate the emigration estimates was hampered by time constraints and lack of

detailed documentation. Overall, there was insufficient time to evaluate each step of the

methodology and to check the reasonableness of assumptions. However, these limits were

accepted as part of the project’s limitations.
29

Oosse Estimates

Limitations to Methodology

The focus of Oosse’s work was to create emigration rates. By using rates, the emigration

component would vary in correspondence to changes in the base population. However, in order

to create the greater detail, Oosse had to use several data sources and make additional

assumptions about the foreign-born population.

Although using multiple data sources allowed Oosse to create the detail necessary, there needs to

be more research to understand whether the data sources sufficiently reflect the characteristics of

the foreign-born population. Oosse used NCHS life tables to proportionally redistribute

estimates of emigrants from an age category to single years of age. Oosse also incorporated an

estimate of the percentage of the foreign born that were unauthorized without any further

information about the characteristics of the unauthorized. Therefore, to remove the unauthorized

population from the base population, we used the same percentages across different age-sex

combinations. However, we know from existing research, that the unauthorized population is

most likely to be men in the working ages. There was no documentation of how the proportions

were calculated, only who provided the information. In order to replicate the results it would be

best to know who provided the data and how they were manipulated.

Limitations to Replication Effort

Oosse produced memos explaining the methodology in a systematic list, and centralized all the

spreadsheets and data in one workbook. However, at times, the documentation was difficult to

follow and a further description of data sources was needed. For example, as mentioned
30

previously, Oosse incorporates an assumption about the unauthorized population in order to

remove them from the base population but there is no source data for the assumption. The exact

source of these assumptions and data were undetermined. In addition, Cuba is assumed to have a

zero emigration rate. Although return migration to Cuba is likely to be difficult, there is no

documentation or justification why the assumption was made. Further research would be

necessary to determine if this was a reasonable assumption.

E. RESULTS

Replication of Ahmed and Robinson Estimates

Table 4 presents the results obtained by the DAPE replication efforts compared to the Ahmed

and Robinson results by sex, race, and selected/non-selected countries. Although we were

unable to duplicate Ahmed and Robinson’s results, we arrived at a similar estimate when

applying the methodology and assumptions used by Ahmed and Robinson. According to the

DAPE validation results, the estimated number of emigrants is 1,940,355 for the ten-year period

from 1980-1990. This result is 8,813 emigrants smaller than Ahmed and Robinson’s ten-year

total emigration estimate of 1,949,168 emigrants.

As an input to the net international migration component for the national estimates and the

demographic analysis estimates for 1990, Ahmed and Robinson calculated a rounded annual

emigration estimate of 195,000. If we followed the same logic, the DAPE replication annual

emigration estimate would be approximately 194,000.
31

The differences between the DAPE replication estimates and the Ahmed and Robinson estimates

exist throughout the age, sex, race, period of entry, and selected/non-selected country of birth

distribution. We were able to closely replicate the estimates produced for the before 1980

entrants for both the selected and non-selected countries. Differences occurred when attempting

to replicate the 1980 to 1990 entrant emigration estimates. Validation efforts for the before 1980

entrant estimates were aided by the existence of a few SAS programs created by Ahmed. The

remainder of the DAPE validation estimates, however, were produced based on piecing together

information published in Ahmed and Robinson’s working paper. In all likelihood, a large

proportion of the differences occurs as a result of differences in race classification by country of

birth for the 1980 to 1990 period of entry. After reviewing the results, however, we were unable

to isolate the origin of the differences.

Analysis efforts were terminated prematurely, as the time allotted to complete replication efforts

for both sets of estimates was extremely brief.

Evaluation of Oosse Estimates

Table 5 presents the results obtained by the DAPE analysis efforts compared to the Oosse results

by sex, race, and selected/non-selected countries. DAPE estimates produced and compared to

Oosse’s estimates were generated as input for other DAPE teams. We were able to replicate

Oosse’s results to the exact total number of foreign-born emigrants for 1980-1990. Differences

in the total from Ahmed and Robinson, Oosse, and the DAPE estimates originate from Oosse’s

assumption that Cubans do not return to reside in their country of birth. Time constraints

prevented a thorough comparison between the Oosse and Ahmed results and the imposed 1990

race and Hispanic origin distribution.
32

Creation of New 1990-2000 Estimates

As noted above, due to time constraints and possible weaknesses in the current methodology

(especially the assumption of equal census coverage in using a residual approach) and/or data

sources, we were unable to produce 1990-2000 foreign-born emigration estimates.

Is the assumed flow of foreign-born emigration realistic?

DAPE validation and analysis efforts were severely limited by time constraints and the lack of

knowledge and research existing on emigration of the foreign-born population. When compared

to historical emigration trends at the aggregate level, the estimates produced by Ahmed and

Robinson and Oosse appear to be in alignment with past trends. However, the foreign-born

emigration statistics and estimates that exist are of questionable quality. The DAPE validation

efforts for Ahmed and Robinson’s estimate produced a similar estimate. Evaluation of the Oosse

estimates determined that the estimates are methodologically sound and accurate. However, a

more thorough analysis of the methodology used to create the Ahmed and Robinson estimates

and the estimated characteristics of the estimates from Oosse and from Ahmed and Robinson are

needed.

Based on the research DAPE Task Team 6 was able to complete in the time allotted, we were

unable to determine if the assumed flow of foreign-born emigration is realistic. However, the

Ahmed and Robinson estimates and the Oosse estimates represent the most recent and reliable

data on emigration available. In order to answer the above stated research question, the U.S.

Census Bureau should devote additional resources to further analyze existing data and to develop

new estimation methodology.
33

F. REFERENCES

Ahmed, B. and G. Robinson. 1994. “Estimates of Emigration of the Foreign-born Population:

1980-1990.” Population Division Working Paper No. 9, U.S. Census Bureau.

Borjas, G. and B. Bratsberg. 1996. “Who Leaves? The Outmigration of the Foreign-born.” The

Review of Economics and Statistics 81(1): 165-176.

Crouch, A. 2000. “The Differential Mortality of the US Born and the Born Abroad by

Race/Ethnicity, Age and Sex.” Unpublished Memorandum, Population Division, U.S.

Census Bureau.

Duleep, H. 1994. “Social Security and the Emigration of Immigrants.” Social Security Bulletin

57(1): 37-51.

Immigration and Naturalization Service, U.S. Department of Justice. 2000. Statistical Yearbook

of the Immigration and Naturalization Service, 1998. U.S. Government Printing Office:

Washington, D.C.

Mulder, T. et. al. 2001. “U.S. Census Bureau Measurement of Net International Migration to the

United States: 1990 to 2000.” Population Division Working Paper No. 51, U.S. Census

Bureau.

Oosse, M. 1998. “Procedures used to estimate annual emigration rates of the foreign-born by

age, sex, and 14 country of birth groups, 1980-1990.” Unpublished Memorandum,

Population Division, U.S. Census Bureau.

Passel, Jeffrey S. 1999 “Undocumented Immigration to the United States: Numbers, Trends, and

Characteristics.” In Illegal Immigration in America: A Reference Handbook. Edited by

David W. Haines and Karen E. Rosenblum. Westport, Connecticut: Greenwood Press.

P. 27-111.
34

U.S. Census Bureau, Population Division. 2001. Demographic Analysis – Population Estimates

Research Project: Project Information Folder.

Warren, R. and J. Peck. 1980. “Foreign-born Emigration from the United States: 1960 to 1970.”

Demography 17(1): 71-84.

Warren, R. and E. Kraly. 1985. “The Elusive Exodus: Emigration from the United States.”

Population Trends and Public Policy Occasional Paper No. 8, Population Reference

Bureau, Washington, D.C.

Woodrow-Lafield, K. 1996. “Emigration from the USA: Multiplicity Survey Evidence.”

Population Research and Policy Review 15: 171-199.
35

Appendix A: Description of SAS Programs Used to Replicate Ahmed and Robinson’s 1980-1990

Emigration Estimates.

Step Description SAS Programs Data

# Input Output

 Pre-1980 Selected

1 Acquire 1980 base population adjusted for

cases with unknown country of birth.

FB80CEN fb80cen.dat * fb80t.dat *

fb80m.dat *

fb80f.dat *

2 Create a file containing the foreign-born

population enumerated in the 1990 census.

Recode the country of birth from 111

categories to 40.

d_fb90_c40 fb111_ad.dat * d_fb90_c40.dat

3 Calculate the preliminary number of emigrants

for the total population that entered before

1980 by age, sex, country of birth, and period

of entry.

d_FB_EMIG d_fb90_c40.dat

d_fb80f.dat

d_fbemig_t.dat

d_fbemig_m.dat

d_fbemig_f.dat

4 Recreate the number of emigrants and the

emigration rate for SELECTED countries by

age, sex, and race group, and period of entry.

d_Fb_1980_select d_fbemig_m.dat

d_fbemig_f.dat

d_Fb_1980_sel.dat

d_Fb_1980_sel_race.dat

d_Fb_1980_sel_rate.dat

d_Fb_70_79_sel.dat

1980-1990 Selected

5 Calculate the proportional distribution of the

1980-1990 entrant foreign born population

enumerated in 1990, the average length of

stay, the mid-point of age in 1990, and the

average age at entry.

d_Fb_8090_midpt d_fb90_c40.dat d_Fb_8090_midpt.dat

6 Estimate the 1980-1990 number of emigrants

(and rates) for SELECTED countries that

entered 1980-1990 by age, sex, and race

group.

d_Fb_emig_8090 d_fb90_c40.dat

d_Fb_8090_midpt.dat

d_Fb_70_79_sel.dat

d_SR_1990_15.prn *

d_emig_8090_age.dat

d_ERSR_8090_age.dat

1980-1990 Non-Selected

7 Create data sets for the 1980-1990 entrants

enumerated in 1990 by age, sex, country of

birth, and period of entry NON-selected

countries.

d_fb_8090_nonsel d_fb90_c40.dat d_fb_8090_nonsel.dat

8 Estimate the number of 1980-1990 entrant

emigrants for NON-selected countries by age,

sex, and race.

d_Fb_emig_8090_non

sel

d_ERSR_8090_age.dat

d_Fb_8090_nonsel.dat

d_Fb_emig_8090_nonsel.

dat

(continued on next page)
36

SAS Programs Used to Replicate Ahmed and Robinson’s 1980-1990 Emigration Estimates

(continued).

Step Description SAS Programs Data

# Input Output

Pre-1980 Non-Selected

9 Create data set that contains the 1980

enumerated foreign born that entered before

1980 for NON-selected countries by age,

sex, race, and period of entry.

d_Fb_1980_nonsel.sas d_fbemig_m.dat

d_fbemig_f.dat

d_Fb_1980_nonsel.dat

10 Estimate the number of before 1980 entrant

emigrants for NON-selected by age and

race.

d_Fb_emig_1980_non

sel

d_Fb_1980_nonsel.dat

d_Fb_1980_sel_rate.dat

d_Fb_emig_1980_nonsel.dat

 Final Estimates

11 Merge four files with the estimated number

of emigrants for the before 1980 and 1980-

1990 entrants and selected/non-selected

countries to estimate the 1980-1990

emigrants by age, sex, and race.

d_Fb_emig_final d_Fb_1980_sel.dat

d_emig_8090_age.dat

d_Fb_emig_8090_nonsel.

dat

d_Fb_emig_1980_nonsel.

dat

d_Fb_emig_final.dat

d_Fb_emig_94.dat

(*)existing data
37

Appendix B: Categorical Age Variables Used to Replicate Ahmed and Robinson’s

1980-1990 Emigration Estimates.

13 categories

(and total)

15 categories

1 Total

2 0-4 1 0-4

3 5-9 2 5-9

4 10-14 3 10-14

5 15-19 4 15-19

6 20-24 5 20-24

7 25-29 6 25-29

8 30-34 7 30-34

9 35-39 8 35-39

10 40-44 9 40-44

11 45-54 10 45-49

11 50-54

12 55-64 12 55-59

13 60-64

13 65-74 14 65-74

14 75+ 15 75+

 Source: DAPE Team 6, Population Division, U.S. Census Bureau.
38

Appendix C: Country of Birth Variables Used to Replicate Ahmed and Robinson’s

1980-1990 Emigration Estimates.

Country classification for the 1980-1990 estimate period (40 categories with 8 regional and total

categories that were not used in programming):

All Countries, Total

North & Central America, Total

3 Mexico

4 Cuba

5 Dominican Republic

6 El Salvador

7 Guatemala

8 Canada

9 Haiti

10 Jamaica

11 Trinidad & Tobago

12 Other N. & C. American Countries

13 South America, Total

14 Argentina

15 Colombia

16 Ecuador

17 Peru

18 Other South American Countries

19 Europe, Total

20 France

21 Germany (East & West)

22 Greece

23 Ireland

24 Italy

25 Netherlands

26 Poland

27 Portugal

28 Spain

29 U.S.S.R

30 United Kingdom

31 Yugoslavia

32 Other European Countries

33 Asia, Total

34 Middle East, Total

35 Iran

36 Israel

37 Other Middle Eastern Countries

38 South & East Asia, Total

39 China & Taiwan

40 India

41 Japan

42 Korea

43 Philippines

44 Other S. & E. Asian Countries

45 Africa, Total

46 Oceania, Total

47 Australia

48 Other Oceania
39

Country classification for the 1990 Census (111 categories):

1 Mexico

2 Cuba

3 Dominican Republic

4 Costa Rica

5 El Salvador

6 Guatemala

7 Honduras

8 Nicaragua

9 Panama

10 Other Latin N & C America

11 Canada

12 Belize

13 Bahamas

14 Barbados

15 Haiti

16 Jamaica

17 Trinidad and Tobago

18 Other West Indies

19 Other N and C America

20 Argentina

21 Bolivia

22 Brazil

23 Chile

24 Colombia

25 Ecuador

26 French Guyana, Suriname

27 Guyana

28 Paraguay

29 Peru

30 Uruguay

31 Venezuela

32 Other South America

33 Albania

34 Austria

35 Belgium

36 Bulgaria

37 Czechoslovakia

38 Denmark

39 Finland

40 France

41 Germany (East, West, Berlin)

42 Greece

43 Hungary

44 Ireland

45 Italy & the Vatican

46 Netherlands

47 Norway

48 Poland

49 Portugal

50 Romania
40

51 Spain

52 Sweden

53 Switzerland

54 United Kingdom

55 Yugoslavia

56 U.S.S.R. (as reported)

57 Baltics (Est.-Lat.-Lith.)

58 Other Northern Europe

59 Other Eastern Europe

60 Other Southern Europe

61 Other Western Europe

62 Europe, not specified

63 Iran

64 Iraq

65 Israel

66 Jordan

67 Lebanon

68 Saudi Arabia

69 Syria

70 Turkey

71 Other Middle East

72 Afghanistan

73 Bangladesh

74 Burma

75 China

76 Hong Kong

77 India

78 Indonesia

79 Japan

80 Cambodia

81 Korea

82 Laos

83 Malaysia

84 Pakistan

85 Philippines

86 Sri Lanka

87 Taiwan

88 Thailand

89 Vietnam

90 Other South and East Asia

91 Algeria

92 Cape Verde

93 Egypt

94 Ethiopia

95 Ghana

96 Kenya

97 Liberia

98 Libya

99 Morocco

100 Nigeria

101 South Africa

102 Sudan
41

103 Tanzania

104 Uganda

105 Zimbabwe

106 Other northern Africa

107 Other Africa

108 Australia

109 New Zealand

110 Other Oceania

111 Antarctica

Source: Population Division, U.S. Census Bureau.
42

Appendix D. Demographic Analysis–Population Estimates (DAPE) Research Project

Related to Evaluating Components of International Migration (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 No. 58, 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 No. 59,

U.S. Census Bureau.

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

Temporary (Legal) Migrants. Population Division Working Paper No. 60, 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 No. 61, U.S. Census Bureau.

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

Migration: Foreign-Born Emigrants. Population Division Working Paper No. 62, U.S.

Census Bureau.

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

Migration: Native Emigrants. Population Division Working Paper No. 63, U.S. Census

Bureau.

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

Puerto Rico and the United States. Population Division Working Paper No. 64, U.S.

Census Bureau.
43

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 No. 65, U.S. Census Bureau.

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

Nativity Data. Population Division Working Paper No. 66, U.S. Census Bureau.
Table 1. The number of immigrants and foreign-born emigrants by decade: 1900-1989.

[In thousands]

Period

Immigrants to 

the US

Foreign-born 

emigrants 

from the US

Ratio of emigrants 

to legal 

immigrants

Total, 1900-1989 38,319 12,231 0.32

1980-1989 7,869 11,950 20.25

1970-1979 3 4,334 1,176 0.27

1960-1969 3

3,213 900 0.28

1950-1959 3 2,500 425 0.17

1940-1949 3

858 281 0.33

1930-1939 3

699 649 0.93

1920-1929 3

4,295 1,685 0.39

1910-1919 3

6,348 2,157 0.34

1900-1909 3 8,203 3,008 0.37

1

 From U.S. Immigration and Naturalization Service, 1998 Statistical Yearbook, Table 1.

2

 Assumption of 195,000 annual emigrants estimated by Ahmed and Robinson, 1994. 

 "Estimates of Emigration of the Foreign-born Population: 1980-1990.", U.S. Census 

 Bureau Technical Working Paper no. 9

3

 From Warren and Kraly, 1985. "The Elusive Exodus: Emigration from the United 

 States." PRB Population Trends and Public Policy paper no. 8, Table 1.
Table 2. Foreign-born emigrants for the national

estimates: 1990 to 2000.

[July 1 to June 30]

Year Foreign-born emigrants

1990 (4/1-6/30) 50,915

1990-1991 203,709

1991-1992 205,798

1992-1993 209,172

1993-1994 212,351

1994-1995 214,401

1995-1996 218,295

1996-1997 222,533

1997-1998 228,048

1998-1999 231,204

1999-2000 (7/1/-4/1) 176,138

Total (1990-2000) 2,172,564

Source: Mulder, T. et. al. 2000. "U.S. Census

Bureau Measurement of Net International 

Migration to the United States: 1990 to 2000." 

Population Division Working Paper No. 51, 

U.S. Census Bureau.
Table 3. Ahmed and Robinson categorization of selected and non-selected countries

and race and Hispanic origin by country of birth.

Race/Origin Selected Countries Non-Selected Countries

Hispanic Cuba Mexico

Dominican Republic El Salvador

Other North and Central 

America

Guatemala

Argentina Peru

Colombia

Ecuador

Other South America

Spain

Non-Hispanic White All countries in Europe 

(except Spain)

Middle Eastern countries

Canada

Australia

Black Africa (as a whole) Haiti

Jamaica

Trinidad and Tobago

Asian and Pacific Islander China Other South and East Asia

India

Japan 

Korea

Philippines

Other Oceania

Source: Ahmed, B. and G. Robinson. 1994. "Estimates of Emigration of the Foreignborn Population: 1980-1990." Population Division Working Paper No. 9, U.S. Census

Bureau.
Table 4. 1980-1990 foreign-born emigrants as estimated by Ahmed & Robinson and DAPE, and the difference between the two, 

by selected and non-selected countries, race groups, and sex.

Non- Non- NonRace/Origin Total Selected 2 Selected 3

Total Selected Selected Total Selected Selected

Total 1,949,168 1,582,203 366,965 1,940,355 1,572,771 367,584 -8,813 -9,432 619

 Male 1,009,882 799,124 210,758 1,002,344 794,315 208,029 -7,538 -4,809 -2,729

 Female 939,286 783,079 156,207 938,011 778,456 159,555 -1,275 -4,623 3,348

Hispanic 438,755 207,959 230,796 451,274 220,657 230,617 12,519 12,698 -179

 Male 248,129 110,839 137,290 255,098 117,923 137,175 6,969 7,084 -115

 Female 190,626 97,120 93,506 196,176 102,734 93,442 5,550 5,614 -64

Non-Hispanic White 878,463 878,463 0 868,675 868,675 0 -9,788 -9,788 0

 Male 427,565 427,565 0 422,070 422,070 0 -5,495 -5,495 0

 Female 450,899 450,899 0 446,605 446,605 0 -4,294 -4,294 0

Black 130,707 81,580 49,127 118,676 68,728 49,948 -12,031 -12,852 821

 Male 67,101 43,851 23,250 57,797 37,143 20,654 -9,304 -6,708 -2,596

 Female 63,606 37,729 25,877 60,879 31,585 29,294 -2,727 -6,144 3,417

API 501,242 414,201 87,041 501,730 414,711 87,019 488 510 -22

 Male 267,088 216,871 50,217 267,379 217,179 50,200 291 308 -17

 Female 234,155 197,331 36,824 234,351 197,532 36,819 196 201 -5

1

 Ahmed, B. and J.G. Robinson. 1994. "Estimates of Emigration of the Foreign-born Population: 1980-1990." Population Estimates

 and Projections Technical Working Paper no. 9, U.S. Census Bureau.

2

 API and Non-Hispanic White male and female do not add to total due to rounding errors.

3

 Using middle assumption (50%).

4 DAPE Team 6, Population Division, U.S. Census Bureau.

Ahmed and Robinson (1994) 1 DAPE Replication (2001) 4 Difference

Number of FB emigrants 1980-1990 Number of FB emigrants 1980-1990 Number of FB emigrants 1980-1990
Table 5. 1980-1990 annual average foreign-born emigrants as estimated by Oosse and DAPE, by country of birth and sex.

Country of Birth Total Male Female Total Male Female

Total 190,415 98,556 91,859 190,414 98,556 91,858

Mexico 20,068 11,948 8,120 20,068 11,948 8,120

Cuba - - - - - -

Canada 11,282 5,135 6,147 11,282 5,135 6,147

Yugoslavia 1,983 1,013 970 1,983 1,013 970

India 5,275 3,103 2,172 5,275 3,103 2,172

Philippines 11,242 5,796 5,446 11,242 5,796 5,446

Africa 6,796 3,980 2,816 6,796 3,980 2,816

China & Taiwan 10,149 5,642 4,507 10,149 5,642 4,507

N, C, and S America 25,235 13,192 12,043 25,235 13,192 12,043

Dominican Republic - - - 2,860 1,514 1,346

El Salvador - - - 1,641 969 672

Guatemala - - - 846 493 353

Haiti - - - 1,534 762 772

Jamaica - - - 2,539 1,173 1,366

Trinidad & Tobago - - - 842 385 457

Other N. and C. America - - - 5,938 3,026 2,912

Argentina - - - 835 461 374

Colombia - - - 2,337 1,256 1,081

Ecuador - - - 1,193 658 535

Peru - - - 526 293 233

Other South America - - - 4,144 2,202 1,942

 (continued on next page)

Oosse (1998) 1 DAPE Results (2001) 2

Number of FB emigrants 1980-1990 Number of FB emigrants 1980-1990
Table 5 (continued). Annual average foreign born emigration as estimated by Oosse and DAPE, by country of birth and sex.

Country of Birth Total Male Female Total Male Female

W. & C. Europe, Australia & New Zealand 52,288 24,469 27,819 52,288 24,469 27,819

France - - - 2,069 954 1,115

Germany (East & West) - - - 11,908 5,058 6,850

Greece - - - 3,093 1,690 1,403

Ireland - - - 1,903 825 1,078

Italy - - - 7,979 3,959 4,020

Netherlands - - - 1,301 654 647

Portugal - - - 3,548 1,810 1,738

Spain - - - 743 414 329

UK - - - 9,608 4,351 5,257

Other European Countries - - - 9,371 4,382 4,989

Australia - - - 765 371 394

USSR and Poland 10,510 4,883 5,628 10,510 4,883 5,628

USSR - - - 6,017 2,791 3,226

Poland - - - 4,493 2,091 2,402

Middle East 12,033 7,234 4,798 12,032 7,234 4,798

Iran - - - 3,998 2,437 1,561

Israel - - - 1,839 1,036 803

Other Middle East - - - 6,195 3,761 2,434

Japan and Korea 13,759 6,565 7,194 13,759 6,565 7,194

Japan - - - 5,334 2,679 2,655

Korea - - - 8,425 3,886 4,539

Other Southeast Asia and Oceania 9,794 5,596 4,198 9,794 5,596 4,198

Other S. & E. Asia - - - 8,705 5,012 3,693

Other Oceania - - - 1,089 584 505

1

 Oosse, M. 1998. "Calculation of Annual Emigration Rates for the Foreign Born, 1980-1990." Unpublished Spreadsheets, 

 U.S. Census Bureau.

2 DAPE Team 6, Population Division, U.S. Census Bureau.

Number of FB emigrants 1980-1990 Number of FB emigrants 1980-1990

Oosse (1998) DAPE Results (2001)