4.38 Time & Tenure with Employers

This section reviews the types of variables present within the NLSY79 main data files that provide information on (1) time spent with an employer measured in terms of the number of hours worked, the type of shift or actual clock hours, the specific dates that employment began and ended, and total tenure in weeks; (2) time spent away from an employer during which the employment contract was maintained or renewed, commonly called a within-job gap; and (3) periods of time when the respondent was neither working for an employer nor serving in the active forces. Time spent away from any employer, commonly called a between-job gap, is measured in units of one week or more.

Hours Worked: During each survey, information is collected on (1) the number of hours during the survey week that a respondent worked at all jobs; (2) the number of hours per day and week usually worked at the CPS job; and (3) the usual hours per day and per week worked at the non-CPS Jobs #1–5. Post-1987 surveys differentiated, for each job, the number of hours worked at home from the hours worked at the place of employment. Follow-up questions double check that these at-home hours are included in the total hours reported working. The creation procedures for the ‘Hourly Rate of Pay‘ variables factor in all values. Two summary variables are created for each year that provide information on the total number of hours that a respondent worked: ‘Number of Hours Worked Since Last Interview’ and ‘Number of Hours Worked Past Calendar Year.’

Survey Instruments & Documentation: The “Current Labor Force Status (CPS)” and Employer Supplement sections of the main questionnaires and the 1980 through current survey year Employer Supplements collect information on hours. The hourly summary variables are created from the week-by-week arrays produced by the NLSY79 Work History program. 

Data Files: Information collected on hours worked both at all jobs and at the CPS job has been placed in the “CPS” area of interest, while information related to Jobs #1–5 is located in “Job Information.” The series of summary variables is in “Key Variables.” Since 1993, Job #1 is always the CPS job if there is one.

Shift & Times Worked: Data on the type of shift usually worked at the respondent’s current or most recent (CPS) job, e.g., “day shift,” “evening shift,” “split shift,” etc., have been collected during all but the 1986 and 1987 surveys. Beginning with the 1986 survey, information on the actual times (24 hour clock) that a respondent usually began and ended the CPS job is available. Coding categories for the 1988 and 1989 shift variables were collapsed into “same or fixed shift” and “shift rotates.” All respondents were asked a follow-up question beginning in 1990 on the actual or usual time work began and ended during the last week (or most recent week) they worked.

Survey Instruments: The “Current Labor Force Status (CPS)” section of the main questionnaires gathered information on shift and clock hours worked until 1993 for CPS job. From 1994 on, this information is gathered in the Employer Supplements for all jobs.

Data Files: The NLSY79 shift variables can be found in the “CPS,” “Job Information,” and “Misc. xxxx” areas of interest. The post-1985 clock variables are in “Misc. xxxx” and “Job Information.”

Periods Working for an Employer Including Unpaid & Paid Leave: Periods of time that a respondent worked for a specific employer can be identified via information collected on start and stop dates, i.e., the day, month, and year that employment began and ended. Those respondents with a stop date for an employer are asked for information on the reason the job ended and whether or not a new job was lined up before the respondent left this job. Interrupted employment with an employer of one week or more during which the respondent was either on unpaid leave or unpaid vacation is also detailed. The total number of such separate within-job gaps is identified, along with the specific start/stop dates and the main reason for not working, e.g., “on strike,” “on layoff,” “quit job but returned to same employer,” “job ended but began again,” “attending school,” “health problems,” “childcare problems,” “pregnancy,” etc.

Active job search by the respondent during a period of not working, e.g., whether the respondent was looking for work during “some,” “none,” or “all” weeks, is specified. For those respondents who indicate that “some” weeks of a non-working period were spent looking for work or on layoff, information is available on the number of weeks duration for each period of unemployment or layoff, the total number of weeks spent looking and not looking, and the main reason he or she was not looking for work. Users should note that the specific week numbers during which the respondent was unemployed versus out of the labor force within a single gap are not available if both statuses apply. Information is collected only on the total number of weeks that were spent in either of the two non-employed labor force states. For example, an eight week within-job gap that occurred between week number 152 and week number 160 may identify two of those weeks as weeks of unemployment and six of those weeks as out of the labor force, based upon responses given. It will not designate the specific week numbers 154 and 155 as the precise two weeks that the respondent was unemployed as opposed to out of the labor force.

During post-1987 surveys, female respondents (only) are asked for information on the total number of separate periods of paid leave from an employer which were taken due to either pregnancy or birth of a child. Start and stop dates are collected for each period of leave.

Types of information collected about periods of paid and unpaid leave are summarized in Table 4.38.1.

Table 4.38.1 Gaps in Employment: NLSY79 Main Files

Survey Instruments: Each Employer Supplement includes questions on periods working and not working for that employer. The Jobs Calendar, used during administration of the military- and job-related sections of the main questionnaire, and the Employer Supplement, function to (1) provide a graphic summary of a respondent’s military and employment history since the date of last interview and (2) identify the duration of gaps between periods of labor force activity. Each calendar gives the interviewer the week numbers attached to the last few calendar years; weeks are numbered consecutively beginning in January 1978 (week 01) through December of the current survey year (e.g., week 758).

Data Files: Variables related to periods working for an employer have been placed in the “Misc. xxxx” and “Job Information” areas of interest. Those variables related to employment gaps are located in “Periods Not Working within Job Tenure” and can be identified through variable titles that include the phrases PERIOD #, JOB #, and, for many variables, the NOT EMPLD universe.

Related Variables: Assignment of a specific labor force status to each week in the respondent’s work history permits creation of a series of “summary labor force variables.” These variables provide a count of the total number of weeks a respondent spent in a given labor force state calculated for two different periods of time, i.e., the past calendar year and since the last interview. Because these variables, e.g., ‘Number of Weeks Out of Labor Force in Past Calendar Year,’ ‘Number of Weeks Unemployed Since Last Interview,’ etc., summarize time spent in a given labor force state, they are discussed in the "Labor Force Status" section of this guide.

Two other sets of summary variables in which time with a given employer is delineated include (1) ‘Total Tenure (in Weeks) with Employer as of Interview Date Job #X’; and (2) ‘Number of Different Jobs Ever Reported as of Interview Date.’ A description of the tenure variable follows; creation procedures for the jobs ever reported can be found in the "Jobs & Employers" section of this guide.

Total Tenure with Employer: The variable series ‘Total Tenure (in Weeks) with Employer as of Interview Date Job #X’ is created from (1) the start (or last interview) and stop dates for an employer; and (2) a match, if any, of employers identified during the current interview as the same employer from a previous interview year. Tenure in weeks with an employer is first calculated for the period between the date of last interview and the current interview date (tenure since the date of last interview). Next, a match with employers reported during the previous interview is attempted. If such a match is established, the total tenure in weeks with the matched employer from the previous interview is added to the total weeks tenure with that employer since the date of last interview. This creates a cumulative tenure in weeks with that employer from the time the employer was first reported up to the most recent week worked. Tenure with employers for whom no match exists in the previous interview is simply the tenure with that employer since the date of last interview. Further information on matching employers can be found in “Appendix 9: Linking Employers through Survey Years” and in “Appendix 18: NLSY79 Work History Data” included in the NLSY79 Codebook Supplement.

Data Files & Documentation: The tenure variables are located in the “Job Information” area of interest. One tenure variable exists for each of five jobs in each survey year. The topical “Work Experience” section of this guide includes a discussion of these variables.

Periods Not Working or in the Military: During each survey, information is collected on up to six periods since the date of last interview during which a respondent is not affiliated with an employer or in the active forces. Data available for each period of not working include month, day, and year that the period began and ended; the specific week numbers associated with the non-work period; whether any of these non-working weeks (coded as “none,” “some,” or “all”) was spent looking for work or on layoff; and, if some were, the number of weeks spent looking for work or on layoff, the number of weeks the respondent was out of the labor force, and the main reason that the respondent was not looking for work. All respondents with between-job gaps are routed through the periods of no work questions.

Survey Instruments: The periods not working questions can be found in the “Gaps when R was not Working or in the Military” or “Gaps” sections of the main questionnaires.

Data Files: The "Mis; xxxx" and "Between Jobs Gaps" areas of interest contain the gaps between jobs variables.

Comparison to Other NLS Cohorts: The questions asked of NLSY79 young adults closely parallel those in the main youth survey. Beginning in 2000, young adults were not asked for between job gaps and only limited information was collected concerning job gaps over time. 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 report the number of hours usually worked per day and per week; they report exact times shifts begin and end starting in 1995. Older and Young Men reported the usual number of hours per week only.

NLSY97 respondents provide the start and stop dates of each employee and freelance job, as well as military service. The survey also collects information about periods of a week or more when the respondent was not working at a given job. Tenure at current or last job is available for the Older Men for 1966, 1967, 1968, 1969, and 1971, and for the Younger 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. Consult the BLS website at http://www.bls.gov/nls or the appropriate cohort’s User’s Guide for details.