Chapter 1:  Introduction

• 1.1  The NLS of Mature Women Cohort

• 1.2  The NLS

• 1.3  Surveys of the Mature Women

• 1.4  The Data via Download and on CD

• 1.5  Organization of the Guide

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1.1  The NLS of Mature Women Cohort

Comprising 5,083 women ages 30-44 in 1967, the NLS of Mature Women cohort is one of four original groups first interviewed when the National Longitudinal Surveys (NLS) program began in the mid-1960s. The U.S. Department of Labor selected this cohort to enable research on the employment patterns of women who were reentering the workforce and balancing the roles of homemaker, mother, and labor force participant.

In the three decades since the original survey, Mature Women respondents have answered questions about a wide variety of topics. Various interviews have collected information not only about the respondents’ labor force behavior but also regarding education, training, marriage, children, income and assets, attitudes about work and family, and the labor force attachment of spouses and partners. A number of topics specific to the life stage of respondents have also been addressed, such as child care issues in the earlier years of the survey and extensive health, pension, and retirement data in more recent interviews. The newest section of the questionnaire asks about transfers of time and money between respondents, their parents, and their children. The variety of questions and the long time span of the interviews allow researchers to track the experiences of a large group of women from early middle age through their retirement years, permitting examination of many different research topics in a number of disciplines.

This detailed guide is designed for researchers who are either working or planning to work with the NLS of Mature Women. Users who need general information about the NLS surveys should refer to the NLS Handbook. For those not familiar with the NLS, a brief overview of all the NLS cohorts follows.

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1.2  The NLS

The National Longitudinal Surveys are a set of surveys sponsored by the Bureau of Labor Statistics (BLS), U.S. Department of Labor. These surveys have gathered information at multiple points in time on the labor market experiences of diverse groups of men and women. Each of the NLS samples consists of several thousand individuals, some of whom have been surveyed over several decades. The earliest NLS interviews began in 1966 under the original sponsorship of the Office of Manpower, Automation, and Training (now the Employment and Training Administration). These cohorts were chosen in an effort to understand specific issues pertaining to the U.S. labor market, such as retirement, the return of housewives to the labor force, and the school-to-work transition. Since that time, however, the content of the surveys has been expanded to provide useful information on an extremely broad range of topics.

The first four NLS cohorts (Older Men, Mature Women, Young Men, and Young Women) were selected in the mid-1960s because each faced important labor market decisions that were of special concern to policy makers. Although the initial plan called for only a 5-year period of interviewing, high retention rates and widespread research interest led investigators to continue the surveys. In 1977, a survey of all known NLS data users and the recommendations of a panel of experts convened by the Department of Labor resulted in two decisions. The first was to continue the surveys of the four Original Cohorts for an additional five years (as long as attrition did not become a problem). The second decision was to begin a new longitudinal study of a panel of young men and young women.

This new study was initiated to permit a replication of the analysis of the 1960s Young Men and Young Women cohorts and to assist in the evaluation of the expanded employment and training programs for youth legislated by the 1977 amendments to the Comprehensive Employment and Training Act (CETA). To these ends, in 1978 a national probability sample was drawn of young women and young men living in the U.S. who were born between January 1, 1957, and December 31, 1964. This sample included an overrepresentation of blacks, Hispanics, and economically disadvantaged non-black/non-Hispanics. With funding from the Department of Defense and the Armed Services, an additional group of young persons serving in the military was selected for interviewing. This sample of civilian and military youth, called the National Longitudinal Survey of Youth 1979 (NLSY79), was first interviewed in early 1979 and has been re-interviewed 20 times.

The Children of the NLSY79 survey, begun in 1986, further enhanced the NLS. With funding from the National Institute of Child Health and Human Development (NICHD) and a number of additional government agencies and private foundations, detailed information on the development of children born to NLSY79 women has supplemented the data on mothers and children collected during the regular youth surveys. During these biennial surveys, a battery of child cognitive, socio-emotional, and physiological assessments are administered to NLSY79 mothers and their children. In addition to these assessments, the Children of the NLSY79 are also asked a number of questions in an interview setting. Beginning in 1994, children age 15 and older, the “Young Adults,” replied to a separate survey with questions similar to those asked of their mothers.

With the aging of the NLSY79 cohort, another longitudinal cohort has been started. The National Longitudinal Survey of Youth 1997 (NLSY97) collects information on the circumstances that influence or are influenced by the labor market behaviors of youth ages 12-16 as of December 31, 1996. Data on the youth’s educational experiences, along with his or her family and community backgrounds, are also included in the survey. Documenting the transition from school to work, this survey is designed to be representative of the population born during the period 1980 to 1984.

Information on sample sizes, interview years, and the current survey status of each respondent group is presented in Table 1.2.1 below.

Table 1.2.1 The NLS: Survey Groups, Sample Sizes, Interview Years & Status

Administration of the Project. Responsibility for the administration of the NLS resides with the Bureau of Labor Statistics (BLS), an agency of the U.S. Department of Labor. Established in 1884, BLS is responsible for the analysis and publication of data series on employment and unemployment, prices and living conditions, compensation and working conditions, productivity, occupational safety and health, and economic growth and employment projections. Its mission is to promote the development of the U.S. labor force by gathering information about the labor force and disseminating it to policy makers and the public so participants in those markets can make more informed, and thus more efficient, choices.

The NLS program supports BLS in this mission. The surveys are part of a longitudinal research program that includes in-house analyses, extramural grants, and other special projects. The NLS program is housed within the Office of Employment and Unemployment Statistics at BLS.

BLS contracts with the Center for Human Resource Research (CHRR) at The Ohio State University to manage the NLS Original Cohorts and NLSY79, to share in the design of the survey instruments, to disseminate the data, and to provide user services. Collection of data for the Mature and Young Women cohorts is undertaken by the Census Bureau through an interagency agreement with BLS. Data collection for the NLSY79 and the NLSY79 Children samples is subcontracted to the National Opinion Research Center (NORC) at the University of Chicago. BLS contracts with NORC to manage the NLSY97 cohort and to collect the data for this survey; CHRR is subcontracted for data dissemination, documentation, and variable creation.

The project is assisted in its efforts by the NLS Technical Review Committee. Meeting twice each year, committee members provide recommendations regarding questionnaire design, additional survey topics, potential research uses, methodological issues, data distribution, and user services. The committee is multidisciplinary, reflecting the wide range of social scientists utilizing NLS data.

Ultimate responsibility rests with BLS for overseeing all aspects of the work undertaken by the other organizations. For more information about the NLS program, contact:

The National Longitudinal Surveys
Bureau of Labor Statistics
2 Massachusetts Avenue NE, Room 4945
Washington, DC 20212-0001
(202) 691-7410; fax: (202) 691-6425
e-mail: NLS_info@bls.gov
www: http://stats.bls.gov/nls

This detailed guide is designed for researchers who are either working or planning to work with the National Longitudinal Survey of Mature Women cohort. Users who are interested in a general overview should refer instead to the NLS Handbook. Users may also wish to read recent issues of NLS News, a quarterly newsletter, available on-line at http://www.bls.gov/nls.    

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1.3  Surveys of the Mature Women

In 1967, 5,393 women ages 30 to 44 as of March 31, 1967, were designated to be interviewed for the Mature Women Cohort. Blacks were oversampled to ensure that they would be represented in sufficient numbers for analyses. In the same year, initial interviews were conducted with 5,083 (94.3 percent) of the designated women.

Including the first interview in 1967, the cohort has been interviewed 20 times. In the initial survey plan, respondents were to be interviewed yearly over a five-year period. However, due to cost considerations, it was decided to survey respondents biennially rather than annually. In order to permit a survey at the end of the five-year period, the respondents were interviewed in both 1971 and 1972. Because of the usefulness of these data and the relatively small sample attrition, a decision was made at the end of the first five-year period to continue the interviews for another five years. At this point, the interviewing pattern changed to a 2-2-1 schedule; each respondent was contacted by phone approximately every two years, then again in person one year after the second phone interview. The 2-2-1 schedule was continued through 1987, when the decision was made to conduct a personal interview every other year. In total, 13 of the 20 interviews were conducted in person, 6 were administered by telephone, and one was mailed to the respondents. Further information is provided in the “Interview Schedule & Fielding Periods” section in chapter 2 of this guide.

The 1995 survey marked the departure from a paper-and-pencil interview (PAPI) to a computer-assisted personal interview (CAPI). Beginning in this year, the NLS Mature Women and Young Women cohorts have been administered the same survey instrument during the same fielding period. Even though they are collected together, the data for the two cohorts are still presented separately in the data file. This CAPI/CATI survey is administered on a biennial basis.

The surveys have collected three basic types of information: (1) data on the respondent’s work and non-work experiences, training investments, schooling, family income and assets, physical well-being, and geographic residence; (2) background information on the respondent’s family and household composition, and her marital and fertility history; and (3) supplementary data specific to the age, sex, stage of life, and/or labor market attachment of this cohort (e.g., household responsibilities, child care arrangements, care of ill or disabled persons, retirement plans and experiences, volunteer work).

Data elements for the NLS of Mature Women are briefly described in the following paragraphs:

Alcohol and cigarette use. Data are available on consumption of alcohol, frequency of use, and quantity consumed, as well as age at first/last use of cigarettes.

Attitudes and aspirations. The surveys include questions on the respondent’s attitude toward her current job, women’s roles, satisfaction with life, and frequency of depressive symptoms during the past week.

Child care. Collected were extent of responsibility for providing regular child care, attitude toward child care, types of child care utilized, cost of these arrangements, and amount of time per week child care services were necessary.

Demographic and family background characteristics. Information has been collected on each respondent’s race, date of birth, and nationality; her residence and family structure at age 15; and her parents’ birthplaces, life/health status, living arrangements, occupations, and education.

Discrimination. During select survey years, respondents have been asked varying questions on whether they have experienced discrimination at work because of their sex, age, or race.

Educational status and attainment. Data are available on highest grade attended or completed, attainment of a high school diploma or GED, type of high school curriculum, field of study at college, and highest degree received.

Geographic and environmental characteristics.Data include the region of residence; whether current residence is in a Standard Metropolitan Statistical Area (SMSA); geographic mobility comparison codes for current residence versus residence during the initial survey year; and, for the early survey years, size of the local labor market and local area unemployment rate.

Health status and health insurance.Information is collected on the presence and duration of health conditions of both the respondent and other family members that limit the respondent’s labor market participation, presence of physical problems such as vision and hearing difficulties, and the need for and frequency of need for assistance in personal care, transportation, bill paying, and getting about. Recent surveys collected information on health insurance sources for the respondent and her family.

Household composition.For each family member (early survey years) or household member (later survey years) living in the respondent’s household at the time of the survey, information such as relationship to the respondent, sex, marital status, birth date or age, school enrollment status, highest grade completed, and work experience is collected.

Household responsibilities and elder care.Questions have been asked on the extent of responsibility for various household tasks, elder care required by either respondent’s parents or husband’s parents, and care of chronically ill/disabled household members.

Income and assets.Income data include the amount of income received by the respondent, spouse, and other family members in the past calendar year or past 12 months. Asset information includes the total market value of property and/or business owned, savings and retirement accounts, stocks, bonds, and debts such as mortgages.

Labor market status and transitions.Data include current labor force status, i.e., activity during most of the survey week, as well as, for those employed, information on occupation, industry, class of worker, rate of pay, hours worked per week, and attitude toward current job.

Leisure activities and volunteer work. The surveys have collected information on the types and amount of time spent on leisure activities, as well as the extent of unpaid volunteer work.

Marital and fertility histories.Information is available on the respondent’s marital status at each survey date and changes in her marital status over time. Fertility information includes the respondent’s age at the birth of her first child and the birth dates, sex, and life status of her children.

Pension plan characteristic file.Detailed pension plan characteristic information including identification of the type of plan, plan definitions, benefit formulas, and eligibility requirements has been collected. Characteristics of each plan, coded using a protocol developed by the Survey of Consumer Finances, are present on a separate data file; crosswalk variables enable researchers to link respondent-specific information with these plan-specific data.

Retirement plans and experiences. This includes questions on retirement plans and experiences of respondents; presence of compulsory retirement plan at current job; expected age at retirement; eligibility for retirement benefits and number of years covered under Social Security, Railroad Retirement, or other pension plans; age respondent becomes eligible for full/reduced benefits; and amount of monthly benefits.

Training. Questions have been asked regarding participation in, type of, and usefulness of occupational training programs, including types of certificates and diplomas received.

Transfers. In 1997, data were collected on transfers of time and money from the Mature Women to their parents. In 1999, the focus of this section shifted to transfers of time and money to and from the women’s children. The 2001 data collection again focused on Mature Women and their parents, but this time looked at transfers not only to parents but also from them.

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1.4  The Data via Download and on CD

NLS of Mature Women data are available to the public free of charge via download or on CD-ROM at a nominal charge. Each data file contains the cumulative longitudinal record of each respondent from 1967 to the most recent interview. The current data release is the NLS Original Cohort Databases: Mature and Young Women, which includes information on the Mature and Young Women from the initial survey of each cohort through 2001. Subsequent releases will be announced in NLS News, the quarterly NLS newsletter; users can also contact NLS User Services for more information.

In addition to the main file, detailed pension plan data for the Mature Women are contained as a separate file on the 2001 data release. The data include plan definitions, benefit formulas, and eligibility requirements for 815 pension plans under which respondents in the Mature Women cohort and/or their husbands reported coverage during the 1989 interview. These characteristics were gathered from employer descriptions of the various pension plans.

Data for the other two Original Cohorts, the Older and Young Men, are available for download from  <http://www.bls.gov/nls>  and also on the most recent CD-ROM. The CD-ROM includes data from all other NLS cohorts. Most of these data sets, however, are available free-of-charge via download from the BLS Web site.

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1.5  Organization of the Guide

The remainder of the guide is organized as follows:

Chapter 2 contains the technical information on the Mature Women sample. It includes information on sample sizes and retention rates, sampling design and fielding periods, sample representativeness and attrition, and weighting.

Chapter 3 provides the user with practical information on Mature Women data. This section describes how the data are collected and created, arranged on the data file, and presented in the documentation.

Chapter 4 presents summary discussions of sets of variables, arranged alphabetically by topic. Persons interested in reviewing, for example, variables that contain information on a respondent’s labor market status or geographic residence should turn to the respective topical section with that name. Each topical section includes variable summaries, references to relevant survey instruments or documentation items, and cautionary notes to users about inconsistencies in the data.

Appendices are the fifth section of this guide. The appendices present a quick reference guide to the data, a dictionary of key words used in variable titles, and SAS and SPSS programs for separating responses to multiple-answer questions.

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