Immigration Statistics: Information Gaps, Quality Issues Limit Utility of Federal Data to Policymakers
Released: 1998-09-02T00:00:00

Letter

Introduction

Background

“Reliable data is a necessary ingredient for credible policy and its implementation.” So stated the U.S. Commission on Immigration Reform in 1994 (p. xxxi). But the Commission found that throughout its own inquiry, inadequate data made it difficult to assess the impact of immigration policy and of immigration itself on American society.

Dissatisfaction with information on immigration has also surfaced on Capitol Hill. In spring 1996, the Immigration and Naturalization Service (INS) issued a press release with the headline: “U.S. Legal Immigration Down 10.4 Percent in 1995.” The headline is based on a 1994-95 reduction in the number of green cards authorized, and the reduction appears to have been caused mainly by a logjam in INS’ processing of green-card applications. Subsequently, INS and most of the experts testifying at a congressional hearing reported that, in general terms, legal immigration was increasing. At that hearing, it also became apparent that some policymakers and reporters had been confused about whether immigration was increasing or decreasing.

Recent dissatisfaction with immigration statistics comes roughly a decade after a thorough review of immigration statistics (Levine et al., 1985) summed up the situation as a history of neglect and despite some efforts to provide better information. It has been a decade during which levels of legal immigration increased while patterns of immigration shifted further away from the European dominance of the early and mid-20th century to heavier flows of Asian and Latin American immigrants. At the same time, illegal immigration emerged as a major concern, and the INS budget increased dramatically, mainly because of more intensive efforts to curtail illegal immigration. (During the 1990s, INS’ budget quadrupled; it is expected to reach $4 billion in fiscal year 1999—up from less than $1 billion in 1992.)

In recent years, the public—particularly California voters—entered the debate about the value and cost of immigration. And a series of major bills—affecting legal immigration, the transition from illegal to legal status, and the public benefits for which immigrants in various statuses are eligible—were introduced and debated in Congress.

Debates concerning immigration continue. For example, this year Californians passed a hotly contested proposition to end bilingual education. Also, the computer industry asked Congress to increase the number of temporary visas for high-tech workers. Thus, there is an increased need for valid, reliable, and clear policy-relevant information. Congressman Ed Bryant of Tennessee called for INS to answer direct questions, such as: “How many people—in total, including every category . . . enter the United States each year?” The Commission on Immigration Reform (1994) also issued a call for new methods to be developed to meet some of the difficult challenges in immigration statistics, such as estimating the flow of illegal immigrants into the United States.

Definition of Foreign-Born U.S. Residents

The resident foreign-born population is defined here as all persons who were born abroad (to parents who were not U.S. citizens) and who now either (1) are in a permanent legal status (naturalized citizen, legal permanent resident, refugee, person granted asylum) or (2) if in a temporary legal status or here illegally, remain in this country for over a year. The requirement for remaining more than a year is based on the U.N. definition.

Demographic Concepts

Four basic demographic concepts (categories of statistics) are crucial to understanding information on the foreign-born population: • The inflow—or in this report, flow—refers to the movement of foreign-born persons into the United States and, as explained below, their transition into specific legal statuses. • The size of the foreign-born population in the United States (sometimes referred to as “stock”) is the total number of foreign-born persons residing here at any given time, including those who have naturalized. • Net change in the size of the foreign-born population over a specific period of time can be calculated using a demographic balancing equation, accounting for flow, deaths, and emigration (see Bogue et al., 1993; Pollard et al., 1981). The foreign-born population increases when the flow of new residents into the country exceeds the number who emigrate or die. • Emigration refers to persons moving out of the United States to take up residence in a foreign country. In this report, we are concerned with the emigration of only foreign-born persons—not the emigration of persons born in the United States.

Legal Statuses

The foreign-born population may be subdivided into groups, such as those defined by the various legal immigration statuses: legal permanent residents, refugees and asylees, those legally permitted to reside here on a temporary basis, illegal immigrants, and naturalized citizens.

Virtually all laws and policies on immigration differentiate foreign-born persons according to their legal status. Thus, from a policy perspective, legal status is critical information. Consistent with this view, in 1994, the U.S. Commission on Immigration Reform, commenting on the need to improve estimates of the costs and benefits of legal and illegal immigration, stated that confusion results from grouping together illegal immigrants, legal immigrants, and refugees.

Two Types of Flow

In considering the process of immigration flow, we recognized that transitions from one immigration status to another must be considered. Persons who enter the United States in one immigration status often adjust or change to a different status, and statistics have been reported on this process. Such transitions are a form of “flow” (i.e., flow to a particular status). This means that flow can indicate not only new entries into the United States, but also transitions or adjustments to a different legal category or status. We believe that it is important to recognize—and to clearly distinguish between—these two, very different types of flow.

Federal Agencies Providing Statistics on Immigration

Most of the available federal statistical information on the foreign-born is provided by two agencies: the Immigration and Naturalization Service and the Bureau of the Census. INS provides information relevant to flow. INS and Census each provide some information on the size of the resident foreign-born population and net change. Census also provides an estimate of emigration (i.e., the estimated number of foreign-born residents who leave the United States to live in another country). Some additional information is maintained by the Departments of State, Health and Human Services, and Labor.

Objectives, Scope, and Methodology

Objectives

The objectives of this report are (1) to identify policy-related information needs for immigration flow and other key demographic concepts that are relevant to migration; (2) to identify federal statistics on the flow of immigrants (and information gaps) and to determine what is known about the quality of existing statistics on flow; (3) to identify federal statistics relevant to other key demographic categories and to determine what is known about their quality; and (4) to identify strategies for improving immigration statistics.

Scope

The scope of this report is limited to current federal statistics that provide basic demographic, statistical information on the resident foreign-born population. Current federal statistics are defined here as those published by a federal agency for fiscal or calendar year 1996—the most recent year for which statistics were generally available during the time we collected data from federal agencies (from Nov. 1997 to Apr. 1998). With respect to policy-related information needs, our focus is on congressional information needs—that is, the statistical data that can inform congressional debates on immigration issues.

In assessing the quality of federal statistics on the foreign-born, we limited our work to determining what is known about their quality, including what can be determined from logical comparisons and analysis. In exploring new strategies, we initially limited our scope to the development of ideas; in one instance, we were subsequently able to conduct a preliminary, qualitative test of a new method for estimating legal status in a census or survey.

Methodology

Identifying Policy-Related Information Needs

To identify policy-related information needs, we reviewed recent congressional debates, bills, and laws concerning immigration to determine the kinds of basic demographic, statistical information on the foreign-born needed by congressional policymakers. We also reviewed basic texts on demography, which identify key concepts, and consulted with immigration experts. (App. I lists the immigration experts we consulted.)

In reviewing federal agency literature, material from relevant hearings, and laws requiring information on the foreign-born, we found that such information has not been gathered or reported according to a common framework or typology. As noted earlier, there have been instances of confusion in interpreting these kinds of information. Therefore, to identify policy-related information needs concerning the legally and illegally resident foreign-born population, we proceeded through a two-step process, which included • developing a basic typology or set of demographic categories (i.e., a systematic framework defining various types of policy-relevant demographic, statistical information on the foreign-born population and their interrelationships) and • examining, in a general sense, whether these types of information were, in fact, needed by Congress and interested members of the general public.

We developed our information typology (set of demographic categories) in consultation with immigration experts. We then examined the need for these types of information by reviewing laws requiring demographic, statistical information on the foreign-born, past congressional requests for information, and recurrent congressional activities. We discussed our typology with staff at the Immigration and Naturalization Service.

Identifying and Assessing Current Federal Statistics

Using our typology, we identified relevant federal statistics and gaps. Briefly, we reviewed literature published by federal agencies and followed up with officials and staff at INS, the Bureau of the Census, and other agencies.

We then evaluated the quality of the relevant statistics, considering technical adequacy and timeliness as well as the adequacy with which the information was reported. To guide our work, we developed checklists for statistical quality, based on a review of literature (including federal agency standards, published empirical assessments of statistical quality, and evaluation and statistical texts) and discussions with agency staff. We used these checklists to ensure comprehensiveness in interviewing federal agency staff, experts, and users about statistical quality and in reviewing relevant literature. We then developed quality ratings to describe published statistics in each demographic category as problem-free or as limited by conceptual problems and confused reporting, as overcounts or undercounts, or as uncertain or unevaluated statistics. If no published federal statistic could be identified for a demographic category, the descriptive rating consists of the notation that a gap exists.

Identifying Strategies for Improvement

To identify strategies to improve federal statistics on immigration, we (1) logically analyzed the problems we had identified, (2) talked with agency staff and experts about possible approaches, (3) reviewed literature, and (4) developed our own new strategy for collecting relevant data. In particular, based on previous research on survey methods for asking sensitive questions and on demographic methods for estimating illegal immigrants, we devised a new method for interviewing foreign-born respondents and collecting data on their immigration status while protecting privacy—the three-card method. We pretested the three-card method in interviews with foreign-born Hispanics in farmwork settings, at a legal clinic for immigration problems, and at a city “drop-in” center. (These interviews were conducted by members of our staff who are fluent in Spanish.) We then conducted a preliminary test of the acceptability of this method to interviewers and respondents by contracting for 81 interviews with foreign-born farmworkers as a supplement to the National Agricultural Workers Survey (NAWS), debriefing the interviewers who administered the questionnaire, and examining the results for signs of respondent comfort with the series of questions.

We conducted our audit work in accordance with generally accepted government auditing standards between June 1997 and June 1998. Preliminary work on the three-card method was conducted earlier. We did not conduct an audit of how the INS and Census data were initially gathered and processed by the agencies.

We requested comments on a draft of this report from INS, Census, and the Departments of State, Labor, and Health and Human Services. On July 13, 1998, Census provided written comments, and on July 15, INS provided oral comments at a meeting attended by INS officials including the Director of the Statistics Branch. INS’ and Census’ comments are discussed in relevant sections of chapter 5 and appendix III. INS, as well as State and Labor, provided some technical comments and suggestions for clarification, which we incorporated as appropriate. Health and Human Services reviewed a draft and said that it had no comments.

Organization of This Report

Chapter 2 of this report presents our typology of policy-relevant statistical information on the foreign-born population (i.e., the set of demographic categories) and links this typology to policy-related information needs. Chapter 3 identifies and assesses current federal statistical information on immigration flow. Chapter 4 identifies and assesses corresponding information on other key demographic concepts—size of the foreign-born population, emigration, and change in the size of the foreign-born population. Chapter 5 discusses strategies for improvement and makes recommendations to the Commissioner of INS and the Director of the Bureau of the Census.

Appendixes provide more detailed information of concern to technical readers. Appendix I lists the immigration experts we consulted. Appendix II briefly reviews available information on the demographic characteristics of foreign-born residents. Appendix III provides information on the three-card method for collecting survey data on legal status and our preliminary test of its acceptability to both respondents and interviewers. Appendix IV reprints the comments from the Bureau of the Census.

Policy-Related Information Needs

A basic typology of policy-relevant statistical information on the resident foreign-born population can be defined by combining two dimensions: one consisting of four demographic concepts that are relevant to migration (flow, size of the foreign-born population, net change in size, and emigration) and the other consisting of legal statuses (legal permanent residents, refugees and asylees, persons permitted to reside here on a temporary basis, illegal immigrants, and naturalized citizens). We developed the typology (or set of demographic categories) as a tool for sorting and defining different types of statistical information on the foreign-born population.

Reviewing specific policy-relevant information needs with reference to our typology, we found that • Congress has passed laws requiring, either generally or specifically, much of the information included in the typology and, in some instances, has indicated that the information is needed to improve decision-making; • Congressional committees have requested some of the information; and • Virtually all of the information is directly or indirectly relevant to various congressional activities (e.g., information on immigration flow is relevant to establishing or changing numerical limits for certain classes of immigrants and temporary visas).

An Information Typology

To build a policy-relevant framework for types of demographic, statistical information on the foreign-born, we crossed the two dimensions—demographic concept and legal status of the foreign-born, as shown in table 2.1. In doing so, we defined flow with three columns to distinguish new arrivals, transitions to a new status, and total flow to specific legal statuses (e.g., all new LPRs). We defined each of the other demographic concepts—the size of the foreign-born population, net change in size, and emigration—with an individual column. The rows of the table represent major legal statuses. In total, we identified 33 discrete categories, each of which specifies a distinct type of information.

What is critical for policy analysts and for users of information is how accurately measures of immigration reflect the actual patterns of immigration (Kraly and Warren, 1992). The typology in table 2.1 represents a step in the direction of measuring actual patterns and reducing confusion. This is because the typology (or set of demographic categories) can be used as a tool for sorting existing statistics and thus determining where gaps exist. It can also help in the interpretation of information by clarifying concepts such as the distinction between two types of flow. The typology also makes plain the interrelationship of different kinds of statistical information and helps clarify which statistics are directly comparable and which are not.

A Consideration of Policy-Related Information Needs

A review of major immigration laws indicated that they often include requirements for federal agencies to report information on flow, the size of the foreign-born population, net change in size, and emigration. Notably, the Immigration Reform and Control Act (IRCA) of 1986 requires triennial reports to Congress, which are to describe the number of persons who are legally admitted or paroled into the United States within a specified interval as well as those who illegally enter or overstay temporary visas during that interval. This corresponds to the demographic concept of immigration flow. Note that with respect to illegal immigrants, it is important to distinguish two different types of flow: those who “enter without inspection” (EWIs) and those who overstay temporary visas. The distinction is important from a policy perspective because, for example, stronger border controls would not address the overstay issue.

IRCA also requires information on a variety of impacts of immigration, including, for example, the impact on demographics and population size as well as the impact on social services. We note that the impact on population size would logically involve new entries, but not transitions between legal statuses. The impact on social services would occur as a result of both new entries and transitions of legal status—that is, both types of flow—because the foreign-born resident’s specific legal status determines whether or not he or she is eligible for specific benefits. (It is important to note that although information on both types of flow combined is relevant for certain policy purposes, data on combined-flow to a legal status should be treated with caution. This is because it is not always clear to what extent each type of flow is represented; e.g., a change in a combined-flow statistic might reflect a change in the number of new entries or a change in the number of transitions to the status in question—or some combination of the two.)

With respect to the other relevant demographic concepts—the size of the foreign-born population, net change in size, and emigration—the Immigration Act of 1990 requires information on the alien population of the United States as well as rates of emigration and an analysis of trends.

Other laws, while not directly requiring statistical information, nevertheless include mandates that imply such a need. For example, the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 mandates an evaluation of the effort to deter illegal entry into the United States. Such an evaluation would require a variety of statistical information, such as trends in the size of the illegal population (see GAO/GGD-98-21).

There are other indications of the kinds of information that Congress has wanted in recent years. For example, the House Judiciary Report accompanying IRCA indicated that the requirement for the triennial reports is intended to enable Congress to review and study immigration and refugee programs and to consider possible changes to them with the benefit of reliable and detailed data. Congressional committees have requested that we provide statistical estimates, such as projections of legal immigration, to help in decisions regarding numerical limits. Another example would be the congressional request for estimates of the number of certain nonimmigrant workers who transitioned to green-card status (see GAO/PEMD-92-17).

Among the ongoing or recurring congressional activities for which the types of information shown in table 2.1 might be useful are • periodic revisions of numerical limits for LPRs, annual setting of levels of refugee inflow, periodic resetting of limits for certain temporary visas, and annual prioritization of funding and special programs intended to reduce illegal immigration; • periodic redefinitions of (1) the conditions under which illegal immigrants and others can (or cannot) adjust to LPR status and (2) ceilings on the number of asylees who may transition or adjust to LPR status; and • periodic revisions of public benefits available to persons in different immigration statuses, which can in turn influence personal decisions about changing one’s immigration status.

In addition, congressional committees have indicated that they wanted information to address issues such as the impact of foreign workers on the U.S. economy and on the working conditions of Americans (see, e.g., GAO/PEMD-92-17 and GAO/HEHS-98-20). There has also been some interest in the trends in the numbers of naturalized citizens, because they have the right to bring in certain relatives.

Immigration Flow

INS’ annual Statistical Yearbook includes several statistics on immigration flow—particularly, statistics on LPR flow (persons with new green-card status), refugees and asylees, and naturalized citizens. But various quality problems limit the utility of these data for policy purposes. • Conceptual problems make a key trend difficult to interpret and valid comparisons of certain reported data difficult to make; confused reporting compounds the conceptual problems. • Administrative data undercount persons granted asylum as well as those attaining naturalized citizenship. • Data gaps occur for key statistics, such as the number of foreign-born persons who take up residence here each year.

The relevant statistics and descriptive quality ratings (together with the reasons for our ratings) are presented in table 3.1.

The INS Yearbook includes several statistics that seemingly fit our typology for information on immigration flow. As shown in table 3.1, these include, for example, figures for the number of new LPRs who entered the United States in fiscal year 1996 (421,405), the number of persons already here who attained new green-card status (494,495), and the total number of new LPRs (915,900). Similar kinds of data are reported for refugees and asylees and for naturalized citizens (see rows B and E of table 3.1). The INS Yearbook also discusses the sources of these data and some of their limitations.

Few, if any, relevant data on flow are reported outside the Yearbook.

Conceptual Problems and Confused Reporting

Trends in the Number of New LPRs

INS’ administrative count of the number of new LPRs combines the flow of (1) new LPR entries to the United States and (2) transitions (or adjustments) to LPR status. But there is a conceptual problem; namely, this statistic represents two different measures, each of which can vary independently. This makes results—particularly for trends—difficult to interpret.

The majority of new LPRs are in category 2, transitions to LPR status. That is, they are not new to the United States; as indicated in tables in the INS Yearbook, they have already been living here for years—typically either illegally or as long-term temporary residents. Various factors can raise or lower the number of green cards authorized for such persons, independently of trends in new entries. Two instances show how this can—and has—happened: • The late 1980s amnesty (through IRCA) for illegal immigrants who had lived here for more than 5 years created a sudden major upswing in the trend line for new LPRs because a large group of illegal residents became eligible to apply for green-card status. This increase was unrelated to any change in the number of persons entering the United States. • A recent change in law (1994) allowed illegal immigrants living in the United States who qualified for green cards to transition to LPR status without leaving the United States—thus shifting the processing of thousands of cases from the Department of State to INS. Because INS could not immediately handle the additional workload, there was a logjam, or slowdown, in issuing the cards to persons already living here. The logical effect of a slowdown is a decrease in the number of cards authorized (i.e., a downturn in the trend line), independent of any change in the number of persons newly taking up residence in the United States. Subsequently, as INS’ capacity to handle the new workload improves, a speed-up in processing would increase the number of cards authorized for persons already living here, creating an upswing in the combined-flow trend line.

INS statistical staff told us that annual trends in the number of new LPRs do not convey a meaningful indication of any demographic concept. They also said it is unclear how to disentangle the effects of processing logjams and catch-ups.

Despite these problems, INS has repeatedly highlighted annual trends in “immigrants admitted” (what we term the combined-flow LPR statistic in table. 3.1). The 1995 and 1996 INS Yearbooks lead off their introductions with the first highlights of current findings, as follows: • “720,461 persons were granted legal permanent residence status . . . a decrease of nearly 84,000 from the year before” (INS 1995 Yearbook, p. 11). • “915,900 persons were granted legal permanent resident status . . . an increase of more than 195,000 over the year before” (INS 1996 Yearbook, p. 11).

In each case, the same page of the Yearbook interprets these trends as either a “decline in immigration to the United States” (1995) or a “rise in immigration to the United States” (1996). The introduction itself does not mention the recent processing problems or that any of the new immigrants counted were already living here.

Readers who turn to the body of the Yearbook will find caveats. However, although tables in the INS Yearbook indicate that the majority of new LPRs were already living in the United States, the Yearbook text indicates only that some were already here.

“The majority of immigrants [LPRs] enter the United States as immediate relatives of U.S. citizens or through the preference system, consisting of family-sponsored and employment-based immigrants. These categories combined accounted for 78 percent of all admissions in 1996.” (p. 18, emphasis added.)

A nonexpert might infer that “enter the United States” means exactly that, not realizing that the majority of new LPRs were already here. (In other words, some readers might not realize that the statement quoted above is supposed to refer to persons entering LPR status—regardless of whether they are already living here, as the majority are.)

Flow of Legals Versus Net Change in Illegals

Another conceptual problem arises because the Yearbook presents statistics relevant to flow for legal immigration—but an estimate for net change in the illegal population. That is, the 1996 Yearbook reports that nearly 1 million persons achieved green-card status in fiscal year 1996 and that the population of illegals is increasing, on average, by 275,000 per year. These two figures are not comparable, however, because flow is a very different concept than net change. Briefly, the difference in concepts is as follows: • The flow of illegal immigrants refers to new illegal EWIs and overstays who resided here for more than a year. (As shown in table 3.1, these two types of flow can be described separately—and a combined number can be provided.) • Net change in the size of the illegal population is calculated, mathematically, as the difference between (1) the flow of illegal residents and (2) legalizations and other exits (emigration, death) from the entire illegal population, as shown in figure 3.1. • Net change may be a positive or negative number. When positive, net change measures the extent to which the flow exceeds legalizations, emigration, and deaths—on the part of the entire population of illegals who were already living here. When legalizations, emigration, and deaths outnumber the entries, net change is negative.

Legal flow cannot be validly compared to net change in the illegal population. The fact that the INS Yearbook reports statistics relevant to flow for legal immigration but net change for the illegal population is compounded by the fact that the Yearbook does not discuss demographic concepts. The Yearbook does not clarify the meaning of immigration flow or net change in population size—or the distinction between the two. Reporting flow for legals and net change for illegals, without clearly distinguishing between flow and net change, could lead to misinterpretations; that is, it might invite invalid comparisons. If a comparison of legal and illegal immigration is to be made, the same demographic concept should be used for data on legals and illegals; for example, legal flow should be compared to illegal flow.

This is important because numerically, the difference (illegal flow versus net change in illegals) could be great. Large numbers of illegal immigrants transition to green-card status (over 120,000 of those authorized to receive green cards in fiscal year 1996 admit to having entered the United States as EWIs), and the emigration of illegal immigrants may also be large. Thus, the flow of illegal immigrants might—in some years—be considerably larger than the reported net change in the size of the illegal population.

Undercounts

Asylees Are Undercounted

We found that INS Yearbook tallies of persons granted asylum are limited to cases processed through INS’ RAPS (Refugee, Asylum and Parole System) data system. Both RAPS and the Yearbook omit asylees whose cases were approved by the Executive Office of Immigration Review (EOIR) rather than INS. Both also omit asylees who enter from abroad after their paperwork is approved by INS—trailing relatives of persons granted asylum (i.e., family members “following to join” a principal asylee)—and processed abroad either by the Department of State or INS. Also omitted were other trailing relatives whose cases were processed in the United States by INS (460 during the first four months of fiscal year 1996).

Table 3.2 summarizes the count of asylees published in the INS Yearbook and the additional counts that we were able to identify by talking with various staff at Department of State, EOIR, and INS and by requesting tabulations from various data systems. INS staff told us that in addition to the 460 cases noted above, they estimate that approximately 1,000 more were processed in the United States during fiscal year 1996; however, the number of trailing relatives approved and processed overseas by INS during fiscal year 1996 could not be estimated.

In sum, the count of asylees published in the INS Yearbook should be increased—probably by more than 50 percent (i.e., from 18,556 to 28,764 or perhaps to an even higher figure). The undercount is not fully described in the Yearbook, apparently because the administrative processes are complex and it is difficult to identify all cases in which asylum was granted. By contrast, however, we found no biases in the Department of State counts of refugees reported in the INS Yearbook.

Naturalized Citizens Are Undercounted

The number of naturalizations reported by INS (row E of table 3.1) is an undercount of new foreign-born U.S. citizens because the tally excludes most minor children. That is, as explained in the INS Yearbook, minor children automatically receive citizenship (by derivation) when their parents naturalize. A separate form is not required for these children, and they are not listed on their parents’ forms. INS counts persons listed on forms; a complete count cannot be obtained without revising the existing form. (We also note that trends in naturalization are affected by processing speed-ups and slowdowns similar to those discussed above for LPRs. As of July 1998, the logjam for naturalization applications was estimated to be between 1.6 and 2 million unprocessed applications.)

Transitions to LPR Status May Be Undercounted

Transitions to LPR status may be undercounted. INS statistical staff told us that in 1996, transitions to LPR status apparently continued to be deflated (to some extent). That is, even after the change in law allowing illegal U.S. residents to transition to green-card status without leaving and reentering, some continued to exit and reenter—preferring the travel to paying the fee required for transitioning without leaving. Although this number may be relatively small, it represents a subtraction from the transitions column and an addition to the new entries column—thus distorting what is reported about patterns of flow to some extent.

Data Gaps

Gap for Flow of Long-Term Residents Admitted With Legal Temporary Status

There is a gap in flow statistics for residents who are admitted with temporary visas (i.e., nonimmigrant visas, such as student visas, temporary work visas, and so forth). The gap occurs because the relevant INS data system does not distinguish newly admitted persons from readmissions of the same person. For example, a foreign student living here for 4 years but visiting his parents briefly every 6 months would be represented as eight short stays—for up to eight individuals—rather than one long stay for a single person. Thus, although durations of stay have been calculated (INS, 1996; Lowell, 1996), they do not correspond to the flow of long-term residents who were admitted with legal temporary status. Moreover, problems at INS or with INS contractors (including computer-processing problems and lack of agreement on what constitutes a valid match) have, since 1992, prevented calculations involving matched entries and exits. And with respect to this and other data systems, INS statistical staff told us that there had been no recent audits or evaluations to test the level of error in data processing and data archiving. Such work might reveal, for example, whether double-counting or lost cases occurred.

Department of State information on issuances of temporary visas cannot fill this gap for two reasons. First, in some cases, a visa allows multiple entries and exits, whereas other visas allow only a single entry so that a new visa is required for each entry and exit. There is no direct correspondence, then, between the number of visas issued and the number of new residents with visas. Second, a single person can, if qualified, be issued multiple visas in different categories—for example, a temporary work visa and a tourist visa could be issued to the same person on the same day—and it would be very difficult to cross-reference records for statistical purposes.

We believe this gap is important because the number of long-term residents living here with temporary visas may be quite large. One analyst (Woodrow, 1998) puts the flow of nonimmigrant residents into the United States at approximately 1 million, perhaps more, in 1990. Under alternative assumptions, possible figures for fiscal year 1996 might range from very roughly 500,000 to 1 million, but the true dimensions are unknown.

Gap for Total Flow of Foreign-Born Residents Into the United States

From the perspective of charting the overall impact of immigration on American society, the most important statistic for which there is a gap may be the total number of new entries who take up residence in the United States each year (total for col. 1 in table 3.1). To fill this gap would require dealing with the gaps and biases in the various estimates for new entries in the various legal status categories: LPRs; refugees and asylees; foreign students, temporary workers, and others here legally for a nonpermanent stay; and illegal residents. Indeed, approximate figures developed for lower and upper bounds could differ by as much as one million persons—leaving policymakers still without a proper information base.

The Resident Foreign-Born Population: Size, Net Change, and Emigration

The Bureau of the Census provides decennial census and intercensal survey data on the size of the foreign-born population and change in size, and it estimates emigration. Although there are no directly relevant administrative records, INS provides some additional information through “composite estimates.” Overall, information on the size of the foreign-born population, change in size, and emigration is limited, as summarized in table 4.1. There are two main reasons for this: • Decennial census and survey estimates apply only to total foreign-born and naturalized citizens (rows E and total in table 4.1). For specific legal statuses, there are gaps and uncertain estimates (rows A through D in table 4.1). Aside from a question on U.S. citizenship, the census and intercensal surveys do not ask about legal status. (One reason is that questions on the respondent’s legal status are very sensitive and might result in biased answers or affect responses to other questions.) INS efforts to fill data gaps without additional data collection efforts have resulted in uncertain estimates. • The data provided by Census for total foreign-born and naturalized U.S. citizens have not been rigorously evaluated. The unevaluated estimates are at least somewhat uncertain because of the questions about adequate coverage of the foreign-born population and other quality issues that have been raised by a number of analysts. Moreover, problems have cropped up in estimating emigration—and also in reliably quantifying net change.

We also found that the information in table 4.1 cannot be accessed by referring to just one or two publications. Rather, policymakers and other information consumers must first identify and access a variety of sources (including the Internet), then piece results together—with no guide to their comparability.

The Available Data

The Alien Address Report Program (an annual registration system maintained by INS) was discontinued in 1981. Until its demise, that system was a source of administrative data on the population of legally resident aliens (i.e., noncitizens). Since all resident aliens were required to register, the number living here would be represented by the number registering—provided that all legal aliens complied. The registration system was discontinued partly for budgetary reasons, but also because not all aliens reported, and the value of the information was unclear.

Likewise, administrative systems to record emigration by aliens and U.S. citizens, begun early in this century, were discontinued (in the 1950s) partly because they were believed to underestimate permanent departures.

After the Alien Address Report Program was discontinued, the decennial census represented, until recently, the only remaining regularly scheduled collection of data on the size of the foreign-born population. Occasional supplements to the Current Population Survey (CPS) included questions on nativity and citizenship. Then, starting in 1994, such questions were added to the CPS on a regular basis, providing information on the foreign-born population in intercensal years.

Gaps and Uncertain Estimates

Lack of Census and Survey Data on Legal Status

Neither the census nor the CPS asks about the legal status of noncitizens—or whether they are, in fact, here illegally. There are good reasons for this: such questions fall under the heading of “threatening” survey questions (Bradburn and Sudman, 1979); many respondents might not answer these questions truthfully; and others might avoid participating altogether if they hear that such questions will be asked. In addition, the Bureau of the Census is concerned about privacy invasion issues.

Uncertain Composite Estimates

In an effort to fill data gaps, INS developed “composite estimates” for the number of illegal residents and for the number of legal permanent residents. Although these estimates represent a step forward (because they provide some information that would otherwise not be available), they are necessarily uncertain. That is, it is difficult to determine whether the figures might be underestimates or overestimates and to judge what the magnitude of misestimation might be.

INS’ composite estimate of the current number of illegals residing here is based mainly on the following three calculations—each of which is characterized by uncertainty: • First, INS calculates an estimate of illegal “overstays”—persons who entered legally on a temporary basis and failed to depart. These estimates are uncertain for several reasons: INS’ data system does not track many legal entries by Mexicans and Canadians (Department of Justice, 1997); so if such persons overstay, they would not be counted. Although the system records other persons’ legal entries and departures, a substantial portion of the departure data is missing each year, and the assumptions INS uses to differentiate missing departure data from actual overstays are controversial. Moreover, INS made its current (1996) estimate by projecting old overstay estimates forward (Department of Justice, 1997). (Data collected after 1992 are deemed not usable because of computer processing problems and lack of agreement on what constitutes a valid match.) • Second, INS calculates the total number of Mexican illegals by comparing administrative data on Mexican legal immigrants to CPS data on total Mexican foreign-born. Here, uncertainty derives from not knowing survey underrepresentation of illegals and from questions about the estimate of emigration (see INS Yearbook).• Third, INS estimates the number of non-Mexican residents who “entered without inspection” (i.e., EWIs from other countries around the world) based on a variety of data, including data from the late 1980s amnesty (that IRCA provided) as well as more recent data on trends in apprehensions. Translating such data into an estimate of the number of current residents necessarily involves assumptions and uncertainty.

Turning to the size of the LPR population, this INS estimate is based on an indirect method that includes subtracting the estimated number of illegals (just discussed) from the number of foreign-born aliens (i.e., noncitizens) estimated in the CPS. Thus, the uncertainties regarding the estimate of illegals are necessarily carried over to the estimate of the number of foreign-born residents with green cards.

With respect to the INS estimate of net change in the size of the illegal population from year to year (275,000), we note that this estimate is derived by comparing composite estimates for two points in time (October 1992 and October 1996) and dividing the total change into equal amounts of change for each year. Hence, this estimate is marked by the uncertainty of the composite estimates of the size of the illegal population. It also reflects a general level of change rather than depicting current trends.

Existing Census and Survey Data: Lack of Evaluation

Valuable as the census and CPS data are—or can be—for estimates of the size of the foreign-born population and other demographic concepts, various analysts have raised questions about quality. The Bureau of the Census believes that the foreign-born are less likely to be enumerated than the native-born, but a rigorous evaluation has not been conducted.

Questions About Underrepresentation of the Foreign-Born in the Census

The Bureau of the Census has carefully evaluated the quality of 1990 census data in the Post Enumeration Survey (PES), but the PES does not distinguish foreign-born residents from native-born. A wide variety of factors have been hypothesized—or identified in indirect analyses and qualitative studies—as contributing to underrepresentation of the foreign-born (see table 4.2). However, it is also possible that reverse errors could occur (Jasso and Rosenzweig, 1987; Schmidley and Robinson, 1998), and in the absence of a rigorous evaluation targeting the foreign-born, the level of net underrepresentation is unknown. For the 1990 census as a whole, however, a rigorous evaluation indicated that undercounting was the more important factor. (For a discussion of the net undercount in the 1990 census and the gross levels of overcounting and undercounting that occurred, see GAO/GGD-91-113.)

Underrepresentation is thought to be concentrated in certain groups of the foreign-born, such as newcomers and illegals, who currently constitute perhaps one-fifth of all foreign-born residents. Unofficial estimates by Census staff put the undercount of illegal immigrants at about 33 percent in the 1980 census; Passel (1986) has suggested a range between 33 and 50 percent. For the 1990 census, various anaylses put the figure at roughly 20-30 percent (Woodrow, 1991; Van Hook and Bean, 1997; Woodrow- Lafield, 1995.)

Possible Underrepresentation of the Foreign-Born in the CPS

Post Enumeration Survey results are used to adjust the Current Population Survey for misrepresentation of specific groups defined by age, sex, race or Hispanic origin, and state of residence. However, it is not known whether the PES adjustments sufficiently improve representation of the foreign-born. If there were no differences between the coverage of foreign-born and native-born persons of the same age, sex, race, and so forth, the PES adjustments should produce accurate CPS estimates of the foreign-born. But as delineated in table 4.1, foreign-born persons may be less likely to be found or identified as residents than native-born persons are, and it is possible that some foreign-born persons may also falsely claim U.S. birth. Thus, despite the PES adjustments, the CPS data could underrepresent the foreign-born.

A different issue could contribute to added underrepresentation of the foreign-born in the CPS: survey nonresponse. As in any survey, some sampled CPS households do not respond to the CPS. CPS response rates are calculated (and adjustments to correct for nonresponse are applied) to geographically large areas—on average, about five areas per state. If foreign-born residents are as likely to respond to the CPS as native-born persons who reside in the same area, there is no problem. But this may not be the case; possible reasons for lower response rates among certain groups of foreign-born include interviewer problems communicating with non-Hispanic immigrants; possible distrust of government or strangers among certain groups (those illegally here, asylees from repressive countries); and for some groups of new immigrants, less familiarity with polling. Thus, higher rates of nonresponse among the foreign-born may contribute to underrepresentation. (An analysis of nonresponse in subareas where foreign-born are concentrated would settle the issue.)

Questions About the Estimation of Naturalized Citizens

Turning to estimates of the number of naturalized citizens, the main concern is not with undercoverage (because citizens are likely to be counted) but rather with the potential for overrepresentation because of false claims of citizenship. This issue is currently being disputed in the literature (Passel et al., 1998; Schmidley and Robinson, 1998). We also note that the CPS, which reinterviews respondents over a 16-month period, has thus far asked the citizenship question only at the first interview. Consequently, the CPS estimates omit some of the most recent naturalized citizens. Currently, this is important because of large numbers of naturalizations—over 1 million persons were naturalized in fiscal year 1996. The Census Bureau is now considering asking the citizenship question in every CPS interview.

Imprecision and Possible Volatility in Estimates of Year-To-Year Change

Census staff have stated that “The CPS nativity data provide a reliable basis for tracking change in the size of the total foreign-born population at the national level” (Schmidley and Robinson, 1998, p. 17). But various Census staff told us that year-to-year change in the size of the total foreign-born population could—and alternatively that it could not—be reliably measured by CPS data. Current estimates of year-to-year net change in the size of the foreign-born population (see table 4.1, total row) seem imprecise; indeed, the confidence intervals are so broad that the estimates might be deemed too imprecise for policy-making purposes. For example, as shown in table 4.1, the 90-percent confidence interval for 1996-97 net change in the size of the foreign-born population ranges from an increase of under a half million to an increase of about 2 million. In other words, the foreign-born population (24 million) may have increased by as little as 2 percent or as much as 8 percent—in a single year.

At our request, Census staff prepared an “annual averages” estimate for the 1996 to 1997 change. The annual averages estimate is, again, an increase of 1.2 million; the confidence interval (800,000 to 1.7 million) is smaller, but still seems imprecise.

It is also somewhat troubling that the trends in year-to-year change appear to be volatile—going from near zero in one year to an increase of over a million the next. It is not known whether some degree of real change occurred, whether an artifact caused the result, or whether the very large difference in estimates is simply from sampling error.

Problems in Estimating Emigration

In using 1980 and 1990 census data to estimate emigration of foreign-born persons, analysts at the Bureau of the Census encountered inconsistent results—apparently because of coverage problems. Bureau of the Census analysts attempted to estimate emigration by tracking arrival cohorts—for example, Mexicans who came to the United States to live during the 1970s—across the 1980 and 1990 censuses. The logic was that by observing the extent to which the size of a cohort dwindled between 1980 and 1990 (while accounting for deaths), one could infer the level of emigration. The approach is logical and reflects basic procedures of demographic analysis. But no dwindling was apparent for Mexico and several other countries; instead, cohorts that arrived in the 1970s appeared to grow between 1980 and 1990, thus yielding negative estimates of emigration—a logical impossibility.

Census staff determined that data for certain countries were unusable, and emigration rates were calculated only for residents from countries with usable data (such as Spain). These rates were then extrapolated to countries with unusable data (such as Mexico). The result was an estimate of 195,000 emigrants each year. But a number of uncertainties are involved; notably, emigration rates may differ for legals and illegals, and if so, extrapolation from countries such as Spain (with mostly legal entries) to countries like Mexico (with large numbers of illegal entries) would be inappropriate. Census staff have recently determined that—in hindsight—the 195,000 is best interpreted as an estimate of emigration on the part of legal foreign-born residents only. One possible problem with this interpretation is that in calculating the 195,000, the Bureau extrapolated emigration rates to all foreign-born residents—a group that includes some illegals.

Reporting Data on Size of the Foreign-Born Population, Change in Size, and Emigration

A policymaker or interested member of the general public would have to access four disparate sources to obtain the estimates shown in table 4.1: (1) the 1996 INS Statistical Yearbook, (2) the INS Web page, (3) an issue of Current Population Reports, and (4) a Bureau of the Census “working paper” on trends and methodological issues. In no case does any one publication refer to all the others, and we could find no central source pointing the interested person to all four. In some cases, less widely distributed publications are needed to understand the methodological bases of the figures. The lack of a central publication relating the results found in one source to those found in another means that readers must gauge the relative quality and comparability of the various estimates, and their interrelationship, for themselves.

In some cases, reporting has not provided the complete information that readers need to judge the quality or stability of the estimates. For example, the Bureau of the Census working paper, entitled “How Well Does the Current Population Survey Measure the Foreign-born Population in the United States,” reports that the nonresponse rate for the CPS is about 6.5 percent, but does not let readers know whether the level of response for communities or areas dominated by foreign-born residents is roughly the same as for other areas. To cite another example, the description of the estimates of illegal overstays in the INS 1996 Statistical Yearbook fails to inform readers that data on overstays have not been available since 1992 and that the 1996 estimates of illegals were achieved by projections of data from earlier years.

Improving Information: Current Initiatives and New Strategies

INS has some initiatives underway to fill data gaps, including an attempt to develop a measure of illegal flow into the United States. In addition, we have identified strategies to improve census and survey data on the size of the foreign-born population. These include (1) eliminating data gaps by collecting survey information on immigration status through a less sensitive form of questioning—the three-card method—and (2) achieving greater certainty for estimates of total foreign-born and naturalized citizens through evaluative analyses, and where needed, corrective adjustments.

C

Otra categoria que no se encuentra en A or B (especifique)

Assuming that the categories are mutually exclusive and exhaustive, it is possible to obtain an estimate of illegals. That is, extending the hypothetical examples above, we would estimate that 75 percent of the foreign-born are in the major legal statuses (35% + 30% + 5% + 5% = 75%).Suppose also that 1 percent picked Box C (some other category). Subtracting these hypothetical estimates from 100 percent yields 100% - 75% - 1% = 24%.

In this hypothetical example, an estimated 24 percent did not claim to be in any legal status, and the implication is that 24 percent of the foreign-born population are illegal immigrants.

Conclusions

For informed decisions on immigration issues, policymakers need information on immigration flow, by legal status. Separate information is needed on the two different types of flow—new entries into the United States and transitions to new legal statuses—because, for example, Congress sets levels of funding for programs to deter illegal immigrants from coming into the United States and also defines conditions for allowing illegals to transition to legal status.

Policymakers also need information on the size of the foreign-born population—again by legal status. And information on emigration helps to gauge the meaning of statistics on immigration flow and on population sizes; that is, it balances information on entries with information on exits, and it indicates the amount of turnover in the resident population.

INS records that are maintained for administrative purposes describe the number of new legal permanent residents (green-card holders), new refugees and asylees, and new naturalized citizens. As reported in the Yearbook, however, these statistics are limited by (1) conceptual problems and confused reporting, (2) undercounts, and (3) information gaps. • Annual trends in the number of green cards issued—a potentially key trend in legal immigration flow—is difficult to interpret because of conceptual problems, and the way it is reported in the Yearbook can confuse readers. Similarly, invalid comparisons of legal flow to data on illegals may occur—again because of conceptual problems exacerbated by confused reporting. • The number of new asylees is an undercount, because the Yearbook tally omits certain categories of persons, such as those who are granted asylum on appeal. The number of persons who newly attained citizenship is also an undercount. • Federal statistics are not available for some categories of immigration flow, such as the number of long-term temporary residents who come to the United States each year. Perhaps most importantly, there is no estimate of the total number of foreign-born persons who take up residence in the United States each year.

Turning to relevant demographic concepts other than flow, statistics are reported in a more scattered fashion; indeed, a variety of INS and Bureau of the Census publications, including the INS Web page, must be accessed.

The Bureau of the Census provides information on the size of the resident foreign-born population, annual net change in size, and emigration. However, decennial census and survey data on the foreign-born have not been evaluated with respect to coverage, misreporting of nativity, and nonresponse. Moreover, there are no separate data for legal permanent residents, illegal immigrants, or most other statuses. (Neither the decennial census nor surveys that target the general population ask questions about foreign-born respondents’ legal status. This is so, in part, because such questions are very sensitive and might result in problems, such as distorted answers to the legal-status question or to other items on the questionnaire.)

The inability to differentiate between key subgroups of the foreign-born population is important from a policy perspective because virtually all laws on immigration are based on specific legal statuses. INS has made efforts to fill gaps for some legal statuses by using the limited data that are available and creating assumption-based models. The resulting estimates are necessarily uncertain because assumptions and judgments are substituted for data.

We identified or developed strategies that might improve immigration statistics. Specifically, we devised a new method for collecting survey data on the legal status of foreign-born respondents. The “three-card method” asks questions that are less sensitive than a direct question requiring the respondent to state his or her specific legal status. It ensures absolute privacy of response and requires no unusual interview procedures. Yet this method allows statistically unbiased survey estimates for all major legal statuses. A preliminary qualitative test of the new method indicated that no one refused to answer the questions. The test population consisted of farmworkers, and although the test was not designed to make statistical estimates, farmworkers’ answers were consistent with an interview population that contains a high proportion of illegal immigrants. Thus, the new method appears to show promise and to merit further testing and development.

We also identified strategies for evaluating survey data on the foreign- born. For example, if a household does not respond to a survey, it is not known whether the residents are foreign-born. Nevertheless, levels of nonresponse can be compared across communities or areas that are known to differ in terms of nativity (based on decennial census data or on the nativity of those who did participate in the survey).

Recommendations

To help correct undercounts, eliminate conceptual problems, and where possible, fill gaps for information on immigration flow, we recommend that the Commissioner of INS (1) evaluate and, where feasible, improve data on flow and (2) utilize an effective information typology (either the one put forward in table 2.1 or an alternative designed by INS) to clearly distinguish different demographic concepts and to determine which statistics can fairly be compared to others.

To eliminate confused reporting of data and estimates concerning immigration flow, we recommend that the Commissioner of INS more clearly report information about trends in legal immigration flow and about the difference between the concepts of flow and net change in the INS Yearbook—or develop a new reporting format that communicates effectively to policymakers and interested members of the general public.

To reduce the uncertainty associated with statistical estimates of relevant demographic concepts other than immigration flow, fill information gaps for specific legal statuses, and address fragmented reporting, we recommend that the Commissioner of INS and the Director of the Bureau of the Census together • devise a plan of joint research for evaluating the quality of census and survey data on the foreign-born; further develop, test, and evaluate the three-card method that we devised for surveying the foreign-born about their legal status; and • either publish a joint report or closely coordinate reports that present information on population size, net change, and emigration.

Agency Comments

INS indicated that it is currently working to improve the clarity of statistical reporting in the Yearbook and that it finds the typology very useful. INS also indicated that attempts to fill certain information gaps may be limited by inherent difficulties and cost considerations. In response to this concern, we added the phrase “where feasible” to the relevant recommendation.

With respect to our recommendation concerning the three-card method, INS made two comments: • First, INS suggested that because it is not an expert in survey methodology, its appropriate role would be limited to providing support and consultation to Census in that agency’s efforts to develop, evaluate, and test the new method. We believe that, as stated above, the recommendation for joint INS-Census work allows latitude for INS and Census to determine their appropriate roles. • Second, INS indicated that it would need an independent evaluation of the three-card method before committing funds to the method’s development. We agree that INS’ obtaining an independent evaluation of the method before proceeding with further development would be prudent.

The Bureau of the Census provided written comments, which raised no objections to our findings on data gaps and the quality of federal statistics on immigration. The Census Bureau also did not object to our recommendation that Census improve reporting and further evaluate existing data on the foreign-born.

However, the Census Bureau stated a concern about its involvement in a survey designed to obtain information on the legal status of the foreign-born. Specifically, Census is concerned that even with the privacy protections of the three-card method, such data collection might compromise the trust and cooperation of the public. Our recommendation is only that the Census Bureau be involved in the development, testing, and evaluation of the new method—not necessarily in any resulting survey. We believe that Census would bring essential expertise to designing and overseeing this work. Testing—even large-scale testing—need not involve data collection by the Census Bureau. We have not revised our recommendation, but in the interest of clarity, we modified appendix III to indicate that contractors or other federal agencies might be used for actual data collection involving the three-card method.