NLSY79 Child and Young Adult

The NLSY79 Child and Young Adult data files include several distinct child age variables at each survey point. The most appropriate age variable to use may depend on one's research objectives. The age variables found in the two Areas of Interest called CHILD BACKGROUND (for all children) and in YA COMMON KEY VARIABLES (for Young Adults) reflect consistency checks and a small number of edits based on additional information. All the created child age variables in the CHILD BACKGROUND area of interest are computed in months, regardless of whether they refer to the Child sample or the Young Adult sample. The codebook, however, displays these "age in months" variables in grouped ranges for ease of viewing. The "age of child at mother's interview date" variables (AGECH) that are assigned to the CHILD BACKGROUND area of interest are created for all children (including young adults), regardless of age. Also, children who are currently young adults are still represented in the variables that indicate child age at assessment date for the survey rounds when they were actually assessed. These child assessment age variables describe the age of the (now) young adult at the time s/he was assessed in prior survey rounds. Generally, most young adults will only have assessment age data for years when they were under the age of 15; however, in the early Child survey years before the start of the Young Adult data collection, some young adults were assessed even though they were older than 14.

The variable that describes the mother's age at the birth of the child (MAGEBIR) is computed in years as is the mother's age at interview date (AGEMOM) which is in the FAMILY BACKGROUND area of interest. The ages for young adult children, available in the Young Adult areas of interest, are also computed in years (e.g., AGE1B assigned to YA FERTILITY AND RELATIONSHIP DATA - CREATED, and AGEDEC, AGEINT in YA COMMON KEY VARIABLES). Users are encouraged to rely on the created age variables rather than any age variables that are direct pick-ups from the questionnaires in the various survey rounds.

Child age variables

There are three relevant age variables for younger children for 1986 through 2014, with AGECHyyyy and MSAGEyyyy also available in 2016. In most but not all instances, the values for these age variables will be the same in any one survey year. Unlike the age variables for the young adults, Child age variables are computed in months, so users who prefer a variable in which the unit is in "years" will need to apply formats or perform a simple conversion.

One series of child age variables (AGECH) references the age of the child as of the mother's interview date. Similarly, there is a Child Supplement assessment age (CSAGE) based on the date the interviewer-administered assessments in the Child Supplement were given. Another age variable series (MSAGE) is linked to the date the Mother Supplement was administered. This variable, termed "Child age at mother supplement date," is appropriate to use when one's research utilizes an assessment that was administered as part of the Mother Supplement questionnaire. The child supplement assessment ages and the mother supplement ages are assigned to the CHILD BACKGROUND area of interest.

Which age variable is best?

Users are advised to exercise caution when applying age variables in conjunction with the child assessment data. Some unedited child date of birth and age variables may appear in the CHILD SUPPLEMENT and MOTHER SUPPLEMENT areas of interest. These items, not available for all children, appear exactly as recorded in the field. Users are generally discouraged from using these items as reported directly from the questionnaires and instead are urged to rely on the child age variables found in the CHILD BACKGROUND or ASSESSMENT areas of interest.

Most of the child assessments are designed to be administered to select age groups of children. Since assessment dates are not always the same for the Child Supplement and the Mother Supplement, users should apply the age variable specific to the supplement that was used to administer the particular assessment. In 2000 (and only 2000) this issue became somewhat more complex in that two mother-report assessments (the HOME and Temperament) were administered in the Child CAPI Supplement for children under age 4. In all years except 2000, it is advisable to use the Mother Supplement age at assessment (MSAGE) for the HOME and Temperament scores. In 2000 the Child Supplement age (CSAGE) was a more accurate indication of assessment age of children under age 4 for these two measures.

Young Adult age variables

There are two Young Adult age variables per round most appropriate for use. In contrast with the variables for the younger children, these are computed as age-in-years. One references the Young Adult's age at his or her interview date and is the variable that most people will want to use. The second is the Young Adult's age on the last day of the calendar year for that survey round. This variable is included because December 31 of a given reference year defines the eligibility of a child for inclusion in the young adult sample and drives some of the skip patterns in the survey starting in 2016. From 1994 to 2014, a child who was 15 or older as of that date was included in the young adult sample. This is the reason that some tables in this guide that provide child age as of an interview date split 14-year-olds into a Child group and a Young Adult group. Beginning in 2016, with the Child Supplement and Child Self-Administered Supplement (CSAS) no longer fielded, children aged 12 and over as of December 31 of the target year have been included in the Young Adult sample. Children aged 12 and 13, however, answer far fewer questions – some of which come from the CSAS – than those 14 and older.

The age at end of year variable can also be useful for defining a sample according to an unchanging age cohort as of any interview year. Interview dates are rarely exactly two years apart; therefore, an individual who is age 20 at one interview point, while typically 18 at the preceding interview, might possibly have been 19 or 17.

Age and demographics

A number of child background variables are provided in the child data files that designate each child's date of birth, birth order, sex, and mother's race. This series of variables is updated in each release to reflect information for all children as of the current survey point, including children who have become young adults. These key variables, assigned to the CHILD BACKGROUND area of interest, are updated to incorporate children born since the last interview. The demographic information is also reviewed in light of mother updates from the main Youth file. Included in this series is an indication of the child's usual residence at the time of the mother's survey. From 1979-1981 and in 1983 and 1985 the child's residence status is based on reports from the mother's household roster. In all other years, child residence information is derived from the child-specific questions on "with whom the child usually lives" in the Fertility section of the main Youth questionnaire. The set of variables in CHILD BACKGROUND also includes a variable, FSTYRAFT (C00052.00), that can be used for connecting child events with information linked to the mother's survey date.

Data updates and child age

Information on a child's date of birth from the Children's Record Form (CRF), an instrument used with the main NLSY79 until recent rounds, was the source of birth date information for the Child Supplements. Beginning in 1988, a Child Face Sheet was introduced as an aid to interviewers in the calculation of child ages. This instrument contained a preprinted child birth date or a place for the interviewer to record the child's date of birth from Part A of the CRF and provided a place for calculating child age in reference to the Child Supplement interview date. This paper Face Sheet was replaced in 1994 by a CAPI feature that computed child age so that interviewers could anticipate which assessments would be administered.

A child's birth date may occasionally be altered on the basis of new information received from the mother in conjunction with the internal evaluation procedures carried out at CHRR. Thus, in a small number of cases, date of birth and child age information may not be completely consistent across all survey rounds. Appendix 5: NLSY79 Supplemental Fertility File Documentation, in the NLSY79 Codebook Supplement, discusses cases in which child birth dates were edited.

Over the interview years occasional revisions have been made to a child's date of birth if it was found to be in error. However, the questions and assessments administered to a child were contingent on the child's age as specified at the time. For a variety of reasons, no attempt has been made to alter the historical age record when a date of birth was revised. Thus, when using age-sensitive information from prior interview points, two options are often possible. One option is to recreate an age variable based on the most recent date of birth of child in conjunction with the interview date in that year. (Note that if this changes the child's age, it may no longer mesh appropriately with the age-specific assessment information collected for that child). The second option is to use the set of age variables from that year, a variable that will be consistent with all the other information gathered from the child in that year. In most instances, this latter option is probably the preferred solution. Finally, in almost no instance would it be appropriate to simply decrement a child's age by the number of years between the most recent interview and the interview round of interest. This can often lead to incorrect estimates for the reason noted above.

In the NLSY79 Young Adult, a respondent's work status can be determined by three constructed variables per round. These variables give users summary measures of the work status of Young Adult respondents on the date of their interview in each round. These new variables are as follows:

WORKyy: WORK STATUS AT DATE OF INTERVIEW – CONSTRUCTED (Rs aged 18 or older)

• 0 No current job at the date of interview
• 1 Working 30 or more hours per week the date of interview (all jobs)
• 2 Working less than 30 hours per week the date of interview (all jobs)

NUMCURJOBSyy: NUMBER OF CURRENT JOBS AT DATE OF INTERVIEW – CONSTRUCTED

TOTHOURSyy: TOTAL HOURS USUALLY WORKED AT ALL JOBS CURRENT ON THE DATE OF INTERVIEW – CONSTRUCTED

Users should note that the WORKyy variables are constructed only for respondents aged 18 or older at the date of interview. The method of collecting labor force participation of younger respondents has varied historically. From 1994 to 1998, respondents aged 18 and younger who reported employment such as babysitting, lawn mowing, and such did so in the same manner as more regular employment. Since 2000, respondents who are aged 18 and under are asked whether they have had these kinds of odd jobs and/or regular employment. A limited number of questions, modelled after those in the Child Self-Administered Supplement, are asked about odd jobs, while much more extensive questions are asked about regular jobs. 

The other work status variables are constructed for all respondents, including the number of current jobs and the total hours worked at all current jobs. Users should be cognizant, however, that the NUMCURJOBSyy and TOTHOURSyy variables for 2000 to the present may understate the work done by younger Young Adults.

Each survey collects information about:

• Current and prior employment (since the date of last interview), including characteristics of the current or most recent employer and of any other employers for whom the respondent worked
• Military service

From the data collected in the Young Adult survey about employee jobs, freelance jobs, and military service, researchers can construct a longitudinal record for the respondents' employment history from the year they were first surveyed to their most recent interview date, except for those first interviewed in 1994, 1996, or 1998: from 1994 through 1998, the reference date for collecting job information was set to January 1 of the year preceding the fielding year. 

Since 2000, this longitudinal record has been maintained even for respondents who are not interviewed every survey round. Each year's questionnaire incorporates retrospective questions designed to recover information lost during previous survey years as completely as possible. For example, a respondent interviewed in 2000 and not interviewed again until 2006 will have a complete labor force history up through the 2006 interview, as employment information since 2000 will be recovered in 2006. Researchers should be alert to the possibility of gaps and discrepancies in some records over time due to inconsistencies in respondent reporting or interviewer error. 

Longitudinal work experience

This section discusses information on various aspects of the longitudinal work experience record available for each Young Adult respondent.

Number of employers

The most basic longitudinal information available for respondents is the total number of employers for whom a respondent worked during a given period and the total number of employers (part-time and full-time) ever reported by a respondent. It is possible to construct a fairly complete inventory of the number of jobs for all respondents from the age of 15 years and older (except for the earliest years of the survey, as discussed above).

"Employers" versus "jobs"

Unless explicitly noted, the Young Adult work data are employer-based. Therefore, any reference to "job" is a reference to a specific employer. Information about specific duties and positions or changes in duties or position is collected, with reference to a specific employer, only at the point of interview. We therefore caution researchers that counting changes in occupations cannot necessarily be equated with total job changes or employer changes. For example, it is possible for a respondent to hold more than one occupation with the same employer during the time between interviews, yet the only occupation specifically reported at the point of interview would be the current/most recent occupation. Likewise, a respondent may hold the same occupation through his or her tenure with several employers.

Part-time and short term employment information

Industry, occupation, and class of worker information is not collected for every part-time or short term employer who is not the primary employer. For jobs lasting less than 10 weeks or jobs where the respondent worked less than ten hours a week, respondents are only asked for employer name, start and stop dates, and hours worked.

Double-counting of employers

Users should be aware that a small degree of double-counting of employers may occur when data are collected. Up through 2008, employment information collected from the last interview was not carried forward to the next round. Beginning in 2010, the names and occupational descriptions for current employers at the most recent interview (limited initially to those from 2008 in 2010) have been carried forward, and YAs are asked a series of follow-up questions on these jobs.

Employer characteristic histories

It is possible to build a limited history of certain employer-based characteristics (earnings/hourly wages, occupation, and so forth). These histories will be limited in the sense that many of these characteristics are reported only at the date of each interview. When change occurs between interviews, in most instances the point of actual change cannot be precisely determined. 

Strictly speaking, it is possible that an occupational change from one interview year to the next could reflect only one of several during the period between interviews. Characteristics such as hourly wage may be of less concern in this regard, as some numeric progression or regression should be apparent. Even for these indicators, however, interim and temporary cutbacks in compensation in times of economic downturn may be missed. 

Job history rosters

To help researchers track YA employment history across rounds, a Job History Roster with unique job IDs has been created for each YA survey round from 1994 to 2020. Each job in a Job Roster has the following variables:

JOB-HISTORY_UID.## - The unique job IDs comprise the year the employer was first reported, followed by the next number in the sequence for that year. For example, if a Young Adult respondent is working for Employer X in 1994, Employer X would be assigned the ID 199401 and would have this ID number in all subsequent rounds the respondent works for Employer X.  If this respondent remains working there for a few rounds, but by 2002 is now working for Employer Y, Employer Y’s ID would be 200201.  If the respondent is also working for Employer Z in 2002, Employer Z’s ID will be 200202.  

JOB-HISTORY_CURRFLAG.## - This variable indicates whether or not the YA respondent is currently working for this employer at the date of the interview.

JOB-HISTORY_START-DATE.##~M, JOB-HISTORY_START-DATE.##~Y – The month and year that the YA respondent first reported starting to work for this employer.

JOB-HISTORY_STOP-DATE.##~M, JOB-HISTORY_STOP-DATE.##~Y – If this is not a current employer, these variables contain the month and year that the respondent reported they stopped working for this employer.  If this is a current employer, these variables contain the month and year of the interview date as a boundary for questions about this employer.

To mitigate the probability of double-counting employers, employer names and other reported information were compared across time, so that in the years where time gaps in reporting existed (1994 to 1998) and the years when no past information was carried forward (1994 to 2008), tenure at jobs can be determined.

Data on respondents' usual earnings (inclusive of  tips, overtime, and bonuses but before deductions) have been collected during every Young Adult survey year for each employer for whom the respondent worked more than two weeks and more than 9 hours a week since the last interview date. The amount of earnings, reported in dollars and cents, is coupled with information on the applicable unit of time, such as per day, per hour, per week, or per year. Between 1994 and 1998, those respondents reporting any unit of time other than "per hour" have been asked a follow-up question on whether they were paid by the hour on that job; if so, an hourly wage rate was collected.

From 1994 to 2014, the wage questions in the Young Adult questionnaire closely paralleled those in the NLSY79. As part of the YA2016 redesign, the choices for reporting both regular and overtime pay were revised based on a review of 'other-specify' responses. These questions were also streamlined so that all respondents report regular rate of pay in one place.

Wage data for the spouse/partner's main job in the preceding calendar year, including time unit and rate of pay, are also collected.

Additionally, each survey year, young adult respondents provide their total income from wages and salary during the calendar year preceding the year of the survey. Starting in the 2000 survey year, if a respondent has difficulty coming up with an exact amount, they are asked for their best estimate. Respondents who are married or who have a partner are asked about wages received by their spouse or partner.

Comparison to Other NLS Cohorts: In the NLSY79, data on respondents' usual earnings (inclusive of tips, overtime, and bonuses but before deductions) have been collected during every survey year for each employer for whom the respondent worked since the last interview date. Two sets of variables provide information based on the combined earnings and time unit data. The first set, 'Hourly Rate of Pay Job #1-5,' provides the hourly wage rate for each job as reported. A second set of variables based on responses to the initial set of wage/time unit questions, entitled 'Hourly Rate of Pay Current/Most Recent Job,' identifies the hourly earnings for the job identified as the CPS job, that is, the job that the respondent held most recently. Starting in 1988, NLSY79 children age 10 and older have been asked about the number of hours usually worked and usual earnings in a week. 

In the NLSY97, several questions are used to determine the job's rate of pay as of the start date. The rate may be defined according to different scales (such as per month, per week, per day, or per hour). Additional information is collected on whether the respondent received any pay from overtime, tips, commissions, bonuses, incentive pay, and other sources when the job started. Questions about freelance employment gather information about the usual number of hours the respondent worked per week and the usual weekly earnings as of the job's start date. In rounds 1-3, respondents who were age 16 or older and reported earning $200 or more per week at a freelance job were considered self-employed.

For the Original Cohorts, rate of pay is available for the CPS job and for many dual or intervening jobs. For more precise details about the content of each survey, consult the appropriate cohort's User's Guide using the tabs above for more information.

Since 2000, information has been collected on all jobs held since either the date of the last interview or January 1, 1994, whichever is more recent. From 1994 through 1998, the reference date for collecting job information was set to January 1 of the year preceding the fielding year. For respondents aging up as first-time young adults, their mother's date of last interview is used. Respondents are asked for the start and stop dates for all employers. These questions allow users to develop a clear employment tenure history since 2000. If researchers want to explore tenure back to 1994, they need to be aware of possible gaps due to the reference dates used.

Comparison to Other NLS Cohorts: The NLSY79 has collected detailed information about start and stop dates for all employers, as well as for military service. NLSY97 respondents provide the start and stop dates of each employee and freelance job, as well as military service. Tenure at current or last job is available for the Older Men for 1966, 1967, 1968, 1969, and 1971, and for the Young Men for 1967, 1969, and 1971. For the Mature and Young Women, users may be able to create tenure variables for the later survey years by combining start and stop dates and data on within-job gaps. For more precise details about the content of each survey, consult the appropriate cohort's User's Guide using the tabs above for more information.

The Young Adult survey has routinely collected information on the occupation of respondents' jobs since last interview, most recent job if none since the date of last interview, and the first job held out of high school, as well as what occupation each certificate, license or journeyman's card was for. In addition to this respondent-specific information, data on occupations are also available for the spouse/partner and the father of the respondent. Verbatim responses to open-ended questions eliciting information on kinds of work and typical duties are entered directly into the survey instrument by the interviewer and subsequently coded using Census coding frames.

In 1994, the decision was made to use the 1970 coding frame, which was still in use in the main Youth data, to make the Young Adult data as directly comparable to the mother's data as possible. In addition, the CPS job, defined as the current or most recent primary job of the respondent, was coded using the 1990 coding frame. This pattern of coding was used for the 1996 and 1998 surveys as well.

For the 2000 survey, the decision was made to switch all jobs except father's occupation to the 1990 Census coding frame. The father's job continued to be coded using the 1970 frame to allow easy comparability with mother's occupation. The CPS job of the respondent was coded in both the 1970 and the 1990 coding frames. Additionally, the 1994-1998 occupation verbatims that had previously been coded using only the 1970 coding frame, were coded again using the 1990 frame. As of the 2000 release, all occupations, except for father's occupation, had both 1970 and 1990 Census codes available (YA 1970 1990 Census Occ and Ind Codes is a downloadable Word file with these codes).

Beginning in 2002, all jobs, including the father's occupation, were coded using the 2000 Census occupation coding frame. Switching to the 2000 coding frame allowed for greater accuracy in occupation coding given the changes in job structure over time. Although this represents a disconnect from previous years, crosswalks between the 1990 and 2000 coding frames are available. Beginning in 2004, all occupations are coded with the Census 4-digit, NAICS-based codes.

Note: For Census industrial and occupational codes go to NLSY79 Attachment 3.

Comparison to Other NLS Cohorts: Regularly fielded sections of NLSY79 instruments have collected information on the occupation of respondents' current/last job, jobs since last interview, military job, vocational/technical or government training programs, type of job to which they aspired, and, for those unemployed and out of the labor force, the kind of occupation they were seeking or planned to seek. In addition to this respondent-specific information, data on occupations are also available for other family members, including the spouse and parents of the respondent.   

For both employee and self-employed jobs, NLSY97 respondents' occupations are coded according to the three-digit census occupational classification system. Freelance jobs that do not qualify as self-employment are coded according to the type of work performed. For the Mature and Young Women, occupation has been coded using 1960, 1980, and 1990 systems in various survey years. The occupations of Older and Young Men were recorded using the 1960 codes for all years; in the final two Older Men surveys, occupation was doublecoded using the 1980 system. For more precise details about the content of each survey, consult the appropriate cohort's User's Guide using the tabs above for more information.

The Young Adult dataset provides a history of military service for Young Adults over age 16, with detailed questions concerning up to two periods of service being asked in each survey round. Depending on their previous Young Adult interview status, respondents are asked either whether they have ever (for first time Young Adults) or since date of last interview (for previously interviewed Young Adults) been enlisted or sworn into any military branch. This section is similar to the military section in the NLS main Youth except that the questions for Young Adults are designed to gather more detailed information on military jobs and training. This section determines which service branches the Young Adult has been sworn into, the time period of service, and also accommodates delayed entry programs. Questions are further tailored depending upon whether service is in the reserves or on active duty. Respondents are also asked about their most recent military job and training and about schooling prior to and during service.

Beginning in 2002, additional questions were targeted to reservists to determine whether they had ever been called into active duty and, if so, when. Beginning in 2010, a series of questions about service-related disabilities were asked of all respondents who have ever served in the military.

In 2008, a new sequence was added to find out about experiences either working as a civilian or being deployed in a foreign country during a combat period. All YAs over age 16 are asked the initial question. Respondents who answer that they have had such experiences are asked additional questions.

The military status variables, "MILITARYyy", constructed for each Young Adult interview round from 1994-2018, allow users to quickly ascertain the military status at the date of interview: not in the military, in the active forces, or in the Guards/Reserves. The military status variables, combined with the work and school status variables, allow users to identify the respondent’s activities in each of these realms at the date of each interview.

Prior to 2000, the Current Labor Force Status (CPS) questions in the Young Adult were very similar to those asked of the NLSY79 main Youth, as Young Adults not currently serving in the active military were asked about work activities during the last week. The survey determined if the respondent did any work for pay or profit, or unpaid work in a family business or farm. There were questions on whether respondents had a disability that prevented them from doing work, the number of jobs held or businesses worked at, and hours per week usually worked at each job. If they were currently laid off, they were asked about the duration of the layoff and job search activities engaged in. Those not working were asked about when they last worked, if they were searching for a job, and whether they were using active and/or passive job search methods. In 2000, the CPS section was eliminated. An official Labor Force Status variable for the week of the survey interview has not been created for Young Adults.

Comparison to Other NLS Cohorts: The NLSY79 surveys have included a "Current Labor Force Status" (CPS) section in all survey rounds. Data are available on the work activity of those NLSY79 children who were age ten and over at the interview date as well as on each mother's survey week activity and work history during quarterly periods preceding and following the child's birth. 

Current labor force status is determined for all respondents in the NLSY97 and the four Original Cohorts for each survey year. However, the current labor force status questions were changed for the women's cohorts in 1995 to reflect the redesign of the CPS. Users should use caution when comparing labor force status from surveys before these years to the NLSY79. For more precise details about the content of each survey, consult the appropriate cohort's User's Guide using the tabs above for more information.

Verbatim responses to questions such as "What kind of business or industry is this?  What do they make or do?" have been recorded within the Young Adult questionnaire in the Employer Supplements during each year's survey. These verbatims are then coded into various versions of the Census Bureau's industrial classification system which consists of 14 industry groups, representing more than 19,000 industries.

A set of variables, 'Type of Business or Industry Job #1-5,' codes the industry of up to five jobs in which the respondent worked since he or she was last interviewed. 

In 1994, the decision was made to use the 1970 coding frame, which was still in use in the main Youth data, to make the Young Adult data as directly comparable to the mother's data as possible. In addition, the CPS job, defined as the current or most recent primary job of the respondent, was coded using the 1990 coding frame. This pattern of coding was used for the 1996 and 1998 surveys as well.

For the 2000 survey, the 1994-1998 industry verbatims that had previously been classified using only the 1970 coding frame were coded again using the 1990 frame. As of the 2000 release, all industry verbatims, except for father's occupation, had both 1970 and 1990 Census codes available (YA 1970 1990 Census Occ and Ind Codes is a downloadable Word file with these codes).

Beginning in 2002, all jobs were coded using the 2000 Census industry coding frame. Switching to the 2000 coding frame allowed for greater accuracy in industry coding given the changes in job structure over time. Although this represents a disconnect from previous years, crosswalks between the 1990 and 2000 coding frames are available. Beginning in 2004, all industries are coded with the Census 4-digit, NAICS-based codes.

Note: For Census industrial and occupational codes go to NLSY79 Attachment 3.

Comparison to Other NLS Cohorts: Information has been collected in all NLSY79 surveys on the type of industry for all jobs that respondents have worked. Industry is collected each year from NLSY97 respondents for both employee (respondents age 14 or older) and self-employed jobs (respondents age 16 or older) according to the industrial classification system. For the Mature and Young Women, industry has been coded using 1960, 1980, and 1990 systems. The industries of Older and Young Men were recorded using 1960 codes for all years; in the final two Older Men surveys, industry was doublecoded using the 1980 system. For more precise details about the content of each survey, consult the appropriate cohort's User's Guide using the tabs above for more information.

Young Adult respondents provide the number of hours they usually work for each job reported, as well as the number of hours their spouse/partner usually worked per week at all jobs in the past 12 months.

Shift and Times Worked 

From 1994 to 1998, the Young Adult survey included questions about the usual start and stop times, as well as the type of shift, for all of the respondent's jobs plus their spouse/partner's main job during the last year. These questions were eliminated in 2000 and 2002. Since 2004, type of shift has been asked about all of the respondent's jobs and their spouse/partner's main job in the last year.

Comparison to Other NLS Cohorts: The NLSY79 survey has collected extensive data on hours and shifts worked. Since 1988, NLSY79 surveys have differentiated the number of hours worked at home from the hours worked at the place of employment. Until 1993, information on shift and clock hours worked was collected only for the main job in the CPS section. From 1994 on, this information is gathered in the Employer Supplements for all jobs.

NLSY97 respondents age 14 and over with employee jobs and all respondents with freelance jobs provide information about the number of hours worked each week. The Mature and Young Women regularly reported the number of hours usually worked per day and per week; they reported exact times shifts begin and end starting in 1995. Older and Young Men reported the usual number of hours per week only.