In September 1992, the Committee on National Statistics and the Committee on Population of the National Research Council held a workshop to explore data collection and data preparation on immigration in the United States. One purpose was to assist the Immigration and Naturalization Service in developing a statistical information system, as required by the Immigration Act of 1990. The other purpose was to suggest possible improvements to the data collection and analysis efforts of federal statistical agencies and the social science research community. Using as a basis the presentations and discussions that took place, the committees make the following conclusions and recommendations.

The committees' conclusions regarding research issues cover four areas:

• It is extremely important to examine immigrants by nationality groups, yet the overall sample size of available surveys limits the ability to conduct analysis of immigrants by countries of origin. The need for large-scale data sets—possibly including new longitudinal surveys—on immigrants is a challenge for immigration research.
• Many surveys and the decennial census have limited information for distinguishing immigrant origins. Some surveys include virtually no data on immigrant status (whether a person is a naturalized citizen, a legal immigrant, a refu-

• gee, or a foreign-born person in some other visa status), whereas other surveys (and the census) provide information only on foreign-born persons—yielding limited data, for example, on the children of the foreign-born.¹ At a time when U.S. immigration is both substantial and diverse, research is hampered by the inability to use existing data for immigration studies.
• The experiences of immigrants in the United States vary enormously and affect people's adjustment to life in this country. Studies of the use of welfare programs—to mention one important policy topic—need to distinguish among illegal aliens, legal immigrants, and refugees for analysis. Unfortunately, information on legal status and the visa status (for legal aliens) is absent from most available data.
• Of all the areas that require more research and improved data, no topic requires more systematic attention than family and social networks. The family is an important factor before, during, and after immigration. And ''after'' extends a long time: the status of the family greatly affects the children of immigrants. Several data sets, including the records of the Immigration and Naturalization Service, could benefit from improvements in the study of the immigrant family.

Having noted the priority policy questions for immigration data (see the section on establishing data priorities in Chapter 1), the committees also draw conclusions regarding broad areas for improvement in Immigration and Naturalization Service records:

• Cooperative efforts are needed to improve immigration statistics. The matching of administrative records, especially records on program and welfare use, offers many possibilities for improved immigration data. It would be useful to match welfare records to a sample of recent immigrants, for example, to make comparisons with the native-born. The results of such an effort would be beneficial for both the study of immigration and social program use.
• Coordination between the Immigration and Naturalization Service and the Social Security Administration could provide improved data and should be encouraged. Matching records from the two agencies could provide longitudinal data on earnings for immigrants, an important but neglected topic of policy study. One possibility for exploration would be to assign a social security number to immigrants as part of the Immigration and Naturalization Service's administra-

• tive procedures. A second possibility would be to take a sample of records on entering immigrants from past periods and link them to the Social Security Administration's records to provide data on earnings since arrival in the United States. With Immigration and Naturalization Service data linked to earnings information on individuals, dependents, and relatives, meaningful information on family processes would also be available for study.
• Conducting sample surveys of immigrants, using Immigration and Naturalization Service or other records, would add valuable information about newly arriving immigrants. There are special problems in surveying immigrants because they are widely dispersed in the U.S. population and are few in number in many areas. One possible survey design would be to use a sample of approved applications for a permanent resident visa—known as a green card. A relatively accurate address is provided by green card applicants. It would be possible to obtain information by enclosing a mail questionnaire, perhaps using several different languages, when the green card is delivered.

The committees make two kinds of recommendations: (1) on additional sources for the data needed for program and research purposes and (2) on new questions and refinements of questions within existing data sources in order to improve the understanding of immigration and immigrant trends.

A question on parental nativity (place of birth of respondents' parents) is an important one for the decennial census. Although such information was collected on the 1970 and earlier censuses, it was not included on either the 1980 or the 1990 census. Parental nativity data provide the information required to examine the social and economic characteristics of the sons and daughters of immigrants. Children of immigrants are a critical generation for study: they reflect the success and rapidity of adjustment of immigrants to U.S. society. The children of immigrants are a pivotal, young subgroup of a national population increasingly affected by large-scale immigration. Census questions require a strong political mandate for inclusion; for the 1990 census, there was no adequate mandate for including parental nativity on the questionnaire. The Immigration Act of 1990 now provides a federal mandate for parental nativity information.

An important source of decennial data for immigration research is the Public Use Microdata Sample (PUMS). The Bureau of the Census's 1990 PUMS files are 1 and 5 percent samples of the individual data from the decennial census. All individual identifications, including specific geographic residence, are deleted from the PUMS files in order to preserve individual privacy. The PUMS files are widely used by immigration researchers, particularly for the study of numerically small and widely scattered racial and ethnic groups. One valuable enhancement of the PUMS files would be to add such contextual data as local unemployment rates—the study of the impact of immigration on employment levels requires local-area data.

The Current Population Survey, which produces a great deal of valuable data, is the key federal survey available for immigration analysis. For more than a decade prior to 1991, the Current Population Survey occasionally included questions on parental nativity and other immigration-related issues. Parental nativity—and such related questions as citizenship and year of immigration—are essential for immigration research and should be included as key questions as a regular part of the Current Population Survey.

Subsequent to the September 1992 workshop, and partially in response to discussions at the workshop, a group of federal agencies worked to place a nativity question on the Current Population Survey. As of 1994, the Current Population Survey collects nativity information for household members and parents of members, allowing researchers to distinguish among foreign-born, native-born of foreign-born parents, and native-born of native-born parents. In addition, the survey includes data on the year of entry for immigrants and citizenship status. The survey makes available basic information on immigration for all survey months and for all members of the household. It is notable that these data are available as well for all supplements to the Current Population Survey.

Whereas the Current Population Survey is the key survey for use by immigration researchers, there have been discussions in recent decades about a joint survey in Mexico and the United States for immigration study. Such surveys would have value for policy studies in both countries. They could explore potential immigration, immigration before departure and after arrival, and return migrants. Joint surveys have been discussed before in general terms; there may be a real opportunity for them at this time.

Some valuable changes have occurred in the past decade at the Immigration and Naturalization Service. Some were made in part to respond to an earlier National Research Council report (Levine et al., 1985). One suggestion that emerged from the 1992 workshop has been implemented: the Immigration and Naturalization Service has convened a group that meets regularly to coordinate improvements in federal immigration data.

Despite the changes made in immigration data since 1985—for the Immigration and Naturalization Service and other agencies collecting immigration data—

weaknesses in the data persist: the Current Population Survey questions on nativity have not been asked regularly, data on emigration and illegal aliens remain poor, little is known about foreign students and new citizens, and procedures have not been developed to ensure continued adequate analysis and dissemination of immigration information. Some obvious opportunities for improving immigration data remain. Examples include establishing an advisory committee to advise the associate commissioner and the Statistics Division and conducting a review of all federal agencies that gather immigration data or for which immigration data have a substantial impact (e.g., educational planning).

Workshop participants made suggestions for the Immigration and Naturalization Service to explore the collection of new data, including improving data on nonimmigrants, adding information on immigrant adjustment to information on previous nonimmigrant status, matching administrative records, conducting a longitudinal survey of immigrants, doing special surveys, and sponsoring case studies. Survey data on new immigrants would offer useful additional data for immigration policy research.

A survey of new immigrants would provide cross-sectional data on legal new entrants into the United States. An ongoing survey, perhaps conducted annually or every few years, would also provide baseline data for longitudinal data collection. The workshop did not include discussion of specific proposals for such longitudinal data collection, although future study could weigh the merits and design for such a proposal.

The National Institute for Child Health and Human Development, one of the sponsors of the workshop, requested that the workshop participants address the potential value of a longitudinal survey of immigrants, a type of survey that has been suggested as important for the advancement of immigration research. Participants reviewed several types of data collection for longitudinal data, spending the most time discussing the merits of a prospective sample (a survey of immigrants who are then followed over time). The purpose of the workshop discussion was to understand the value and limitations of such a survey; it was not to propose a specific survey design or to endorse the need for a longitudinal survey. Chapter 7 summarizes the discussion on the value of a longitudinal survey of immigrants, alternatives to a new survey, and some technical issues in survey design.