The Wisconsin Longitudinal Study: A Source of Public Data on Aging in American Families http://dpls.dacc.wisc.edu/WLS/ MEMO110c Keywords: ability, aging, alcohol, aspirations, assets, careers, caregiving, children, cognition, college, depression, divorce, earnings, education, employment, family, fertility, gender, health, households, income, insurance, intelligence, labor force, life course, marriage, menopause, mental health, mid-life, mobility, morbidity, occupations, pensions, personality, physical health, psychological well-being, religion, retirement, siblings, social participation, voting, wealth, and work. The Wisconsin Longitudinal Study (WLS) is a long-term study of a random sample of 10,317 men and women who graduated from Wisconsin high schools in 1957. Survey data were collected from the graduates or their parents in 1957, 1964, 1975, and 1992/93 and from a randomly selected sibling in 1977 and 1993/94. These data provide a full record of social background, youthful aspirations, schooling, military service, family formation, labor market experiences, and social participation of the graduates. The survey data from earlier years have been supplemented by mental ability tests (of graduates and of their siblings), measures of school performance, and characteristics of communities of residence, schools and colleges, employers, and industries. The WLS records for graduates are also linked to those of three, same-sex high school friends within the study population. Social background measures include earnings histories of parents from Wisconsin state tax records. In 1977 the study design was expanded with the collection of parallel interview data for a highly stratified subsample of 2000 siblings of the graduates. In the 1992-94 rounds of the WLS, the sample was expanded to include a randomly selected sibling of every graduate who had at least one brother or sister. Survey content for graduates and siblings was extended to obtain detailed occupational histories and job characteristics; incomes, assets, and inter-household transfers; social and economic characteristics of parents, siblings, and children and descriptions of the respondents' relationships with them; and extensive information about mental and physical health and well-being. The WLS cohort of men and women, mainly born in 1939, precedes by about a decade the bulk of the baby boom generation that continues to tax social institutions and resources at each stage of life. For this reason, the study can provide early indications of trends and problems that will become important as the larger group passes through its fifties. This adds to the value of the study in obtaining basic information about the life course as such, independent of the cohort's vanguard position with respect to the baby boom. In addition, the WLS is also the first of the large, longitudinal studies of American adolescents, and it thus provides our first large-scale opportunity to study the life course from late adolescence through the mid-50s in the context of a complete record of ability, aspiration, and achievement. The WLS sample is broadly representative of white, non-Hispanic American men and women who have completed at least a high school education. Among Americans aged 50 to 54 in 1990 and 1991, approximately 66 percent are non-Hispanic white persons who completed at least 12 years of schooling. The sample is mainly of German, English, Irish, Scandinavian, Polish, or Czech ancestry. Some strata of American society are not well represented. Everyone in the primary sample graduated from high school; about 7 percent of their siblings did not graduate from high school. We have estimated that about 75 percent of Wisconsin youth graduated from high schools in the late 1950s. Minorities are not well represented; there are only a handful of African American, Hispanic, or Asian persons in the sample; given the longitudinal design of the WLS, and the miniscule numbers of minorities in Wisconsin at the time the study began, there is, unfortunately, no way to remedy this omission. About 19 percent of the WLS sample is of farm origin, and that is consistent with national estimates of persons of farm origin in cohorts born in the late 1930s. In 1964, in 1975, and again in 1992, about two thirds of the graduates lived in Wisconsin, and about one third lived elsewhere in the U.S. or abroad. Because the WLS graduates are drawn from a single cohort, age variation is observed across time, rather than in cross-section. However, siblings cover several adjoining cohorts; they were mainly born between 1930 and 1948. In the 1992/93 follow-up survey of WLS graduates, we interviewed 8493 of the 9741 surviving members of the original sample. These included 475 of 850 survivors who were not interviewed in 1975. Almost all graduates were 53 or 54 years old when interviewed. Among randomly selected siblings of the graduates, some 2000 siblings were previously interviewed in 1977. During 1993/94, we interviewed them and approximately 2800 more siblings in this round of the study. The graduate and sibling surveys included a 1-hour telephone interview, followed by a 20-page, self- administered questionnaire. We carried out brief, close-out interviews with a relative of graduates who had died, and, in cases where the selected sibling had died, we obtained close-out data from the original respondent. These new follow-up data, linked with our existing files, are a valuable public resource for studies of aging and the life course, inter-generational transfers and relationships, family functioning, social stratification, physical and mental well- being, and mortality. In the future, we plan to enhance the value of the sample and data with additional data linkages, for example, to locate death certificates for deceased graduates, siblings, and their parents. Documentation, publication lists, and modular public-use data files from the WLS are available from the DPLS web-site (http://dpls.dacc.wisc.edu/WLS/). In addition, a program (WLSGV) is provided for VMS, PC, and UNIX platforms that will generate much of the SPSS or SAS code needed to extract variables and merge data from different modules. Additional source materials about the WLS are available from the Center for Demography and Ecology, The University of Wisconsin-Madison, 1180 Observatory Drive, Madison, Wisconsin 53706, or send e-mail to cdepubs@ssc.wisc.edu. For additional information about the WLS, send e-mail to wls@ssc.wisc.edu. Public releases of the WLS data are also available from DPLS. Data and Program Library Services Phone: (608)262-7962 University of Wisconsin-Madison Fax: (608)262-4747 3313 Social Sciences Building E-mail: dpls@dpls.dacc.wisc.edu 1180 Observatory Drive WWW: http://dpls.dacc.wisc.edu Madison, WI 53706