NLSY79 Child and Young Adult

• Child
• Young Adult

Child

The NLSY79 Child data file does not contain child-specific geographic information for children under age 15. However, to be interviewed as part of the child survey, all children must reside with their mothers for at least part of the year. Limited geographic information about mother's residence in each survey year is available in the main NLSY79 data set, and more detailed information is provided on the restricted-use Geocode data.

The following created variables are provided, for mothers of NLSY79 children, in the main Youth data file:

• REGION. Region of residence at birth, age 14, and survey dates (Northeast, North Central, South, or West)
• URBAN-RURAL. Information on whether the current residence is in an urban or rural county
• Through 1996, this series was based on the respondent's State and county of residence and the "% urban population" data from the County & City Data Book. From 1998-2002 this item was based on whether the respondent was living in an urbanized area or in area with a population greater than 2,500. Beginning in 2004, this item indicates whether the respondent resides within an urban cluster or urbanized area. For further information see the Geocode Codebook Supplement.
• SMSARES. Information on whether the current residence is in a Metropolitan Statistical Area (MSA), the central city of an MSA, or outside of an MSA
• Based upon zip code, State, and county matches with metropolitan statistical designations for place of residence, the location of the respondent is determined to be within or outside of a metropolitan statistical area
• USRES. Beginning in 1988, whether the current residence is in the United States

This mother-based geographic information can be merged with any child's record by using the case identification code. As children age into the Young Adult sample, information on their geographic residence is included in the Young Adult data set as described below. By combining the main NLSY79 and Young Adult with the child file, data users can track geographic residence from birth to the current survey round and can also link information on the location of family members who are also respondents in the NLSY79 or Child/Young Adult surveys.

The geographic data available for mothers in the main NLSY79 survey are described in the Geographic Residence & Neighborhood Composition section of the NLSY79 topical guide.

Young Adult

Geographic residence (public data)

Publicly available created variables for the Young Adult respondent's geographic residence include U.S. region of residence (Northeast, North Central, South, and West), an urban/rural designation for the residence, and whether the residence is in an SMSA (standard metropolitan statistical area). These variables are in the "YA Common Key Variables" Area of Interest. More specific information about geographic residence, including an explanation of missing data, can be found in the restricted-use Geocode data.

Geocode data

Beginning with the 2000 data release, the decision was made to create a set of geocode data files for the Young Adults comparable to those created each round for the NLSY79. A full set of geocode variables was created for all Young Adult years from 1994 to 2000 at that time, and geocode variables continue to be prepared for each new round. These confidential files are available for use only at the BLS National Office in Washington, DC, and at Federal Statistical Research Data Centers (FSRDCs) on statistical research projects approved by BLS. Access to data is subject to the availability of space and resources. Information about applying to use the zip code and Census tract data is available on the BLS Restricted Data Access page.

The Young Adult supplemental data files provide geographic variables from the NLSY79 Young Adult survey data file. Additionally, for survey years 1994-2002, these supplemental data files provide selected variables from the County and City Data Books.

The Young Adult geocode file includes the state and county of residence for each survey round. For the creation of the 1994 through 2002 geocode data, for Young Adults living in their mother's household, the county and state of residence were drawn from the mother's NLSY79 data if the mother was interviewed for that year. For Young Adults not living with their mothers, and those whose mothers were not interviewed, county and state of residence were coded from the Young Adult survey data. In cases where the mother's data were missing or incomplete, Young Adult survey data were used to provide accurate codes wherever possible. Since 2004, all county and state of residence variables were coded from the Young Adult survey data.

The county and state of residence for each Young Adult respondent for each survey year between 1994 and 2002 were matched with the county and state variables from the County And City Data Book data files for both 1988 and 1994 so that geocode data files include selected county-level and SMSA-level environmental variables. Users should note that a decision was made to extract geocode variables for all five 1994-2002 Young Adult survey years from only the 1988 and 1994 County and City Data Book data files. This decision means that the 1994 and 1996 Young Adult geocode variables are not directly comparable to those of their mothers, whose geocode variables were extracted from the 1983 and 1988 County and City Data Book data files. 

The County and City Data Book data files were prepared by the U.S. Bureau of the Census. Related printed matter for each of these data files can be found in the County and City Data Book for the specified year, which is also published by the U.S. Bureau of the Census. 

The Geocode Codebook for the Young Adult survey provides the following detailed information on each geocode variable: its reference number, variable description, coding information, frequency distribution, file name, variable name, and source of the variable. Included are references to pertinent attachments and appendices from the NLSY79 Geocode Codebook Supplement providing supplementary coding and variable creation procedures. Variables are grouped within the geocode codebook according to the year with YA GEOCODE 1994 variables followed by YA GEOCODE 1996 and so forth. 

Users of the Young Adult geocode data are encouraged to review the NLSY79 Geocode Codebook Supplement for greater detail on the geocoding processes as comparable procedures have been used in the Young Adult as in the NLSY79 main file. This supplement has several appendices and attachments, including:

• Appendix 10: Geocode Documentation which provides background information on how the original 1979-1982 geocode tape and subsequent updates were created and how those data were modified to form the subsequent releases.
• Attachment 100: Geographic Regions which provides a listing of those states, which comprise each of the four regions, used in such variables as region of residence and south-non-south place of birth/place of residence at age 14.
• Attachment 102: State Federal Information Processing Standards (FIPS) Codes, which are used to code respondents' state of residence. 
• Attachment 104: SMSA Codes which contains the coding information utilized to classify SMSA, MSA, CMSA, PMSA of residence at each interview date.
• Attachment 105: Addendum to FICE Codes contains the supplementary identification numbers for those colleges and universities not listed in the Education of Directory Colleges and Universities (1981-1982 and 1982-1983 supplement) published by the National Center for Educational Statistics.
• Appendix 7: Unemployment Rates which provides an explanation of how the continuous and collapsed versions of the variable, unemployment rate for labor market of current residence were created.

Geocode data file creation procedure

The software package Maptitude (V4.2) was used in the creation of the NLSY79 Young Adults 1994-2002 geocode data files for Young Adults who could not be matched to previous mother data (see NLSY79 Geocode Codebook Supplement for greater detail). Since 2004, the geocoding process has been undertaken with ArcGIS (V9.2). These programs link respondent address data to standard geographic information such as the FIPS (Federal Information Processing Standards) codes for state and county. Three graduated matching methods were applied, depending on the quality of address data available.

1. Where possible, an automated match was done between the respondent's locating address data and the GIS database.  Address records with matching street segments were assigned the latitude and longitude of the location. In some cases, addresses had to be cleaned before they could be matched by the program. Cleaning involves steps such as standardizing the address format, correcting obvious misspellings, identifying apartment numbers and locating them in the correct field, etc. It does not include any changes that might result in a change in the actual address location.
2. For some addresses, the procedure outlined in Step #1 failed to produce a match between the respondent's address data and the GIS database. In these cases, geocode staff used the Maptitude or ArcGIS program to locate the correct street. If the street number could be located along this street, staff assigned the correct latitude and longitude. However, some streets in the GIS database do not include information about street numbers, and, if this occurred, the address was manually located in the center of the street. The street is then classified as either a short street or a long street where long streets cross Census tract or block group boundaries while short streets do not. As a result, the level of certainty about geographical information is much higher for short streets than for long streets.
3. Addresses unmatched by either of the first two procedures were assigned latitude and longitude coordinates according to a 5-digit zip centroid. A centroid is essentially the midpoint of a ZIP code area. The geographic information is less certain for respondents located using the zip centroid method.

Because some Young Adults had latitude and longitude derived from Maptitude through 2002, while others had these data matched from NLSY79 records for their mothers from years when different systems were used, a quality of match variable equivalent to GEO10 in the NLSY79 geocode data was not released for survey years 1994-2002 but is available for all years after 2002. Quality of match is also available for subsequent survey years. Researchers who need to determine the level of certainty for the respondent's geographic data prior to 2004 may contact NLS User Services for further details.

Supplementary created Geocode variables

College variables

In all Young Adult survey rounds, information was gathered on the name and location of the college or university that the respondent currently or most recently attended. Included in the geocode variables for survey years 1994 through 2000 are Federal Interagency Committee on Education (FICE) codes for these colleges or universities as well as FIPS codes for the state where they are located. Additionally, beginning in 2000, respondents who were in either their senior year in high school or their first year of college were asked about what colleges and/or universities they had applied to. FICE codes are provided for these colleges and universities.

Beginning in 2002, the codes provided for colleges applied to and college attended are UNITID codes from the Integrated Postsecondary Education Data System (IPEDS) database rather than the FICE codes used in previous rounds. A crosswalk between FICE codes and UNITID codes is available in the IPEDS database. For cases where a UNITID code was unavailable but a FICE code existed, the FICE code is provided. A code of 999999 was assigned to cases where neither a FICE code nor a UNITID code could be found for a given college or university.

Child support variables

Information was collected in the 1994-2016 Young Adult rounds about the state in which child support agreements were reached. The FIPS codes for these states are included in the geocode variables for those years.  

Missing data

Following the same convention as the NLSY79 Child and Young Adult public release data, missing data values on the geocode data files are coded -7, which indicates either a) a non-interview for a given year or b) respondents who have a missing value in the data for any variables from the County And City Data Book for the following reasons:

1. Respondents who were in the military or who had an APO address;
2. Respondents who were residing outside of the United States;
3. Respondents whose state or county codes could not be determined.
4. Respondents who reside in a county or SMSA/MSA for which there is missing data for that geographic location from the County And City Data Book for that specific item.
5. Respondents who do not reside in an SMSA for any survey year 1994-most recent who will be missing SMSA level environmental variables for that year.
6. Respondents whose state, county, and ZIP codes for any survey year 1994-most recent do not lead to an unambiguous SMSA designation. This generally applies only to a small number of respondents living in New England.

In the 1994-2002 geocode data, for the 1988 and 1994 metropolitan statistical area variables included in the data, GEO7 and GEO9A respectively, respondents with NECMA codes (i.e. respondents living in the New England states of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont) were not treated any differently than those residing elsewhere. The addition of the "Record Type" variable in the 1988 and the 1994 County And City Data Book data files, GEO9 and GEO9C respectively in the Young Adult Data, allows the user to designate these cases as missing and remove them from the analysis, without having to conduct a county-by-county or state-by-state determination of NECMA/non-NECMA status. These data from the County and City Data Books are not available as part of the geocode data releases for survey rounds after 2002.

Use of the Geocode files

Here are a few suggestions concerning the use of the NLSY79 Young Adult geocode files: First, the data file and the accompanying documentation should be used in conjunction with the printed versions of the 1988 and 1994 County and City Data Book and the IPEDS codes so that researchers have complete information regarding variable descriptions and coding idiosyncrasies. Second, users should familiarize themselves with the NLSY79 Geocode Codebook Supplement. Also, the data must not be used in any fashion that would endanger the confidentiality of any sample member. To use these data, researchers must sign a written licensing agreement consenting to protect respondent confidentiality and to other conditions; agree not to make, or allow to be made, unauthorized copies of the geocode file; and further agree to indemnify the Center for Human Resource Research for all claims arising from misuse of the file.

• Child
• Young Adult

Child

The variable CRACE (child reference number C00053.00) in the NLSY79 Child data file is the mother's race and corresponds to the 'Racial/Ethnic Cohort from Screener' (R02147.00) in the NLSY79 main Youth. This variable designates the respondent as "Hispanic," "black," or "nonblack/non-Hispanic" and provides the basis for weighting NLSY79 data. This variable is collapsed from R01736.00 (SAMPLE-ID in the Child data), 'Sample Identification Code,' which includes such values as "supplemental male black" or "cross-sectional female Hispanic." This code was assigned by NORC to each respondent based on information gathered during the 1978 household screening. In the creation of the 'Sample Identification Code' and thus the 'Racial/Ethnic Cohort' variable, both race and ethnic origin information collected at the time of the 1978 household screening were used. 

In the NLSY79 Young Adult, the variable YARACE corresponds directly to CRAC, based directly on the mother's main Youth variable R02147.00. However, YARACE is created only for young adults ever interviewed as young adults, while the variable CRACE is created for all children in the database, regardless of age.

Young Adult

First-time Young Adults are asked to self-identify their race and ethnic background and give their father's race. Beginning in 2000, Young Adults provided the race/ethnicity of their spouse/partner as well.

Which Young Adults have been asked their race and ethnicity has differed across survey rounds as has the structure of the questions asked:

• In 1994, all respondents were asked both a six-category race/ethnicity question [Black, White (non-Hispanic), Hispanic, American Indian, Asian or Pacific Islander, or Other (SPECIFY)] as well as a detailed ethnic identification question paralleling that asked of their mothers in 1979.
• In 1996, Young Adults not interviewed in 1994 were asked the same two questions.
• In 1998, all Young Adults were branched into these questions because the structure of the race/ethnicity questions was changed significantly. Respondents were initially asked if they were of Hispanic origin, followed by a six-category question asking whether they considered themselves White, Black or African American, American Indian or Alaska Native, Asian, Native Hawaiian or Other Pacific Islander, or Other (SPECIFY).
• The category of "American Indian or Native American" in the detailed ethnicity question was changed to "American Indian" beginning in 1998 in order to reduce confusion on the part of respondents.
• Beginning in 2000, the six-category race question was asked in a "code all that apply" format.
• Since 2000, only new Young Adults are asked the race and ethnicity questions about themselves and their father.

• Child
• Young Adult

Child

The official fertility record in the mother's main Youth record is reconciled with reports in the child interview to ascertain the best determination of the child's sex. The sex of each child CSEX (reference number C00054.00) is created as a cross-round (XRND) key variable for all children regardless of age. CSEX is assigned to the CHILD BACKGROUND area of interest. A comparable variable (YASEX), just for children ever interviewed as Young Adults, can be found in the YA COMMON KEY VARIABLES area of interest.

Young Adult

The Young Adult cohort includes both male and female offspring of the NLSY79 mothers. The Y06774.00 XRND variable indicates a sex of Young Adult composition of 4,434 males and 4,239 females.

Questions about gender identity and sexual orientation were added to the self-report section of the YA2018 survey. In the 2020 interview, these questions were asked of respondents not interviewed in 2018. Although asked in the same section of the survey, these two topics were not asked back to back. These questions are YASR-GENID-1 through YASR-GENID-3 and YASR-SEXOR-1.

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.