NLSY79 APPENDIX 18:

WORK HISTORY DATA

• DESCRIPTION OF THE 1979-2004 NLSY79 WORK HISTORY PROGRAM
  • Description of the 1979-94 PL/1 Program
    • CALC Procedure
    • FILL Procedure
  • Changes between the 1979-86 and the 1979-87 Work History Data File
  • Changes between the 1979-87 and the 1979-88 Work History Data File
  • Changes between the 1979-88 and the 1979-89 Work History Data File
  • Changes between the 1979-89 and the 1979-90 Work History Data File
  • Changes between the 1979-91 and the 1979-92 Work History Data File
  • Changes between the 1979-92 and the 1979-93 Work History Program
  • Changes between the 1979-93 and the 1979-94 Work History Data File
  • Changes between the 1979-94 and the 1979-96 Work History Data File
  • Changes between the 1979-96 and the 1979-98 Work History Data File
  • Changes between the 1979-98 and the 1979-2000 Work History Data
  • Changes between the 1979-2000 and the 1979-2002 Work History Data
• DESCRIPTION AND CODES FOR VARIABLES IN 1979-2004 NLSY79 WORK HISTORY DATA
• WORK HISTORY PROGRAMS
• VARIABLES USED IN CREATION OF 1996 AND SUBSEQUENT WORK HISTORY DATA FILES
• NLSY79 WEEK NUMBERS AND CORRESPONDING DATES (separate file)

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DESCRIPTION OF THE 1979-2004 NLSY79 WORK HISTORY PROGRAM

This document provides a general description of the work history program and explains the procedures and the logic that went into the creation of the various arrays in the program. The variables in the work history file are the output of the work history program. While the discussion that follows assumes some knowledge of the program and the acronyms that are used in it, this description provides useful information for all users of the work history data.

The work history program was originally written to create the key work variables like "Number of Weeks Worked since Date of Last Interview," "Number of Weeks Worked in Last Calendar Year," etc. These key variables use all recorded jobs for each respondent (up to 10 jobs). The WEEKLY LABOR STATUS, HOURS WORKED, and DUAL JOBS arrays also were created with data from up to 10 jobs for each respondent. However, only 1% of all respondents have more than 5 jobs in any given survey year, resulting in valid missing data for jobs 6 through 10 for 99% of the sample. In order to reduce the total number of variables, the data file contains the JOB variables for only 5 jobs for each respondent.

The purpose of the WEEKLY LABOR STATUS, HOURS WORKED and DUAL JOBS arrays is to create a longitudinal work history record for each respondent through the 2004 interview date. Because each year's survey collects information on jobs held and periods not working since the date of the last interview, it is possible to construct a continuous, week-by-week record for each respondent.

There are a few exceptions, however. In the 1979 and 1980 surveys, job information was collected only for respondents age 16 and older at the date of the interview. Additionally, the 1979 survey data contain the most cases with inconsistent or invalid employment-related data of any survey year, resulting in a greater proportion of missing gaps in the work history record. For example, in 1979 there are 86 cases that have job dates that exceed the interview date; in 1980, there are 11 cases that have job dates that exceed the interview date; in 1981 there are none.

Users should also note that 1,079 members of the military sample were dropped as of the 1985 survey. In 1991, all members of the economically disadvantaged non-black/non-Hispanic oversample were dropped as well. More information on these sample types is available in chapter 2 of the NLSY79 User's Guide.

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Description of the 1979-94 PL/1 Program

The following is an abbreviated step-by-step description of the 1979-1994 PL/I program. In 1996, the PL/I program was converted to SQL code that replicates the PL/I program and functions. See the section below titled "Changes between the 1979-94 and the 1979-96 Work History Data" for more information.

1. All of the variables used in the program are declared and most are included in the PL/I structure called VARIABLES.
2. The variables common to all respondents, like ID, SAMPLE_ID, etc. are assigned values. The week-by-week arrays are initialized to zero and all of the variables included in the WORK_HISTORY part of the structure are initialized to -4.
3. For each interview year, procedures (VARIABLES1979, VARIABLES1980, etc.) that assign the variables for each survey year are called if the respondent was interviewed. Start and stop dates for jobs and periods not working are sent to the WEEK procedure, where the valid month, day and year variables are converted to a week number, with week 1 being January 1, 1978. If the respondent was not interviewed, then all WORK_HISTORY variables for that survey year are set to -5.
4. After all VARIABLES19XX are assigned, the procedure CALC is called to evaluate the various start and stop dates, to assign codes, and to create the job number for all of the jobs for each interview year. Within CALC, the procedure FILL is called to fill in the codes that are assigned to the WEEKLY LABOR STATUS and DUAL JOBS arrays and to calculate the hours worked during each week that are loaded into the HOURS WORKED array.
5. Finally, the procedure SUMMER is called to calculate and sum the key work history variables.

CALC Procedure

This procedure processes all jobs for each survey year, beginning with the first job. CALC starts by calculating each year the number of jobs since the date of the last interview, assigning a job number, and calculating the hourly wage for each job. If the respondent had the job at the date of the last interview, the start date becomes the date of the last interview, which is then "ceiled" or rounded up using the "ceil" function. Next, if the respondent is currently working at the job, it assigns the interview date, which is "floored" or rounded down using the "floor" function, as the stop date. (All dates at this point have been converted to week numbers in the WEEK procedure.)

If the start and stop dates of the job are valid and do not coincide with an interview date, the start and stop dates are "ceiled". The number of weeks tenure on the job is calculated by subtracting the start date from the stop date of the job. FILL is then called to fill in the week arrays for the particular job. The start and stop dates of the job, the job number, and the number of hours usually worked per week (HOURSWEEK) at the job are sent to the FILL procedure.

If the job had any periods not working associated with it, then each of the four possible periods not working for the employer is processed. If the start and stop dates for the periods not working are valid, a code is assigned indicating whether the respondent was out of the labor force (OLF) or unemployed for the period. If the respondent is OLF the whole period, a code of 4 is assigned. If the period not working is divided between OLF and unemployed, a temporary code of 9 is assigned and the number of weeks unemployed is determined. If the start and stop dates of the period are valid, but the labor force status cannot be determined, a code of 2 is assigned.

The period start and stop dates, CODE, and HOURSWEEK are sent to FILL. If the period dates are invalid, a code of 3 is assigned and start and stop dates of the job are passed to FILL, along with HOURSWEEK. This is only done for the first period not working for the first employer this week.

Next, tenure at the job is again calculated, this time in terms of total weeks on the job instead of just since the date of the last interview. First, a determination is made to see if the employer is the same employer a respondent reported at the time of the previous interview. If there is a previous employer number and the tenure for that previous employer is valid, then the tenure for the job from the previous interview is added to the tenure for the job being processed. Only tenure with an employer that is reported during contiguous survey years can be calculated over the total time spent with an employer. For example, consider a respondent who was interviewed in 1981, 1982 and 1983 surveys. Now suppose the respondent reported having worked for the Labor Department at the time of the 1981 survey and left and then began working for that same employer again by the time of the 1983 survey. Because the employer numbers are only followed between contiguous interviews, there is no way to calculate total tenure with the Labor Department since the respondent did not report that employer during the 1982 survey. Only employers from the previous year's survey are compared with employers reported in the current year's survey.

Finally, CALC evaluates the possible six periods not working or in the military between jobs. For each of the periods not working, the same logic used for the periods not working on a job is used for the periods between jobs.

FILL Procedure

The FILL procedure takes the start and stop dates that have been converted to week number values and fills in values for the WEEKLY LABOR STATUS, HOURS WORKED and DUAL JOBS arrays for each week between stopping and starting dates that are passed to it.

In FILL, the STATUS array is loaded with either a survey year job number or a code signifying that there was not a civilian job that week (a code of 0, 2, 3, 4, 5, or 7). The DUAL JOBS array is loaded with a survey year job number(s) if more than a civilian job is held that week; otherwise it has a value of zero. The HOURS WORKED array is loaded with the number of hours worked on all jobs held that week, up to a maximum of 96.

FILL is called from the CALC procedure for all start and stop dates except for military start and stop dates. Military start and stop dates are determined in the VARIABLES procedures for each year, and FILL is called from those procedures to fill in a code of 7 in the WEEKLY LABOR STATUS array for active military service.

Initially, FILL checks for valid start and stop dates. If the dates are valid, then FILL takes one of three paths. The first path is to evaluate the WEEKLY LABOR STATUS array for that week to see (1) if it contains a job number, (2) if the code passed from CALC is a job number, and (3) if the previous employer number for the job is different from the job number in the WEEKLY LABOR STATUS array. If all of these statements are true, then FILL determines that the job is not a duplication of the job that exists in the WEEKLY LABOR STATUS array for that week.

Next, FILL looks at the DUAL JOBS array to see of there is a job number in DUAL JOBS. If DUAL JOBS already has a job number(s), then the current job number is compared to the job number(s) in DUAL JOBS. If the job number does not exist in DUAL JOBS, then the HOURSWEEK for that job is added to the number of hours for that week and the job number is added to DUA LJOBS. If the job is a duplicate job, then nothing is done to the arrays.

The second path is taken if there is no dual job and if the week dates are associated with a job or if there is not job number in the WEEKLY LABOR STATUS array. If this is the case, FILL tests for two conditions. The first condition is met if COD is 9. (A code of 9 means that the respondent had a period not working that was part OLF and part unemployed.) If COD equals 9, then the HOURSWEEK are subtracted from the hours in HOURS, because the respondent is not working at the job. The number of weeks unemployed (code of 4) is arbitrarily assigned to the middle portion of the weeks not working, and the rest of the period is determined to be OLF (code of 5).

The second condition in the second path tests to see if the value in the WEEKLY LABOR STATUS array is not a code of 4; if COD is a job number then the job number is placed into WEEKLY LABOR STATUS. If there are hours for the week and if the respondent was not working for the employer during this week, then the hours for the week are set to zero if HOURS WORKED is greater than zero. Otherwise, HOURS WORKED receives whatever value is in HOURSWEEK.

The third path FILL can take is if this is a period not working and if there is a dual job. Then, the job number is deleted from DUAL JOBS and HOURSWEEK for the job are subtracted from HOURS WORKED.

Finally, if there are more than four dual jobs in DUAL JOBS then no other job numbers are added to DUAL JOBS because the array for each week is limited to four dual job variables.

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Changes between the 1979-86 and the 1979-87 Work History Data File

In 1987, a few changes were made to the program that created the work history data file. These changes from the 1986 program affected the created labor force participation key variables, the STATUS array, and the HOUR array. In addition, two sets of variables were added for each year: (1) WHYLEFT, the reason that the respondent left each job for each year if they were not currently working at that job at the date of the interview and (2) BREASON, the reason that the respondent was not looking for work during each of the possible six periods not working between jobs for each year.

The following is a more detailed discussion of the changes in the code that were made and the effects of those changes on the key variables and the week-by-week arrays:

1. In the CALC PROC, the stop dates for all jobs and all periods not working were set to the interview date if the dates were greater than zero and if they were greater than the interview date. These changes resulted in an increased number of weeks unaccounted for in calculating weeks not working and in changes in the number of weeks unemployed and out of the labor force across all of the key variables for each survey year. Most of the changes were a difference of one week or a change to an invalid value.
2. In the FILL PROC when hours were subtracted from the weekly HOURS WORKED array, a check was made to determine if the subtraction resulted in a value greater than or equal to zero. If it did not, the value in the HOURS WORKED array for that week was set to zero. If there was no dual job for that week, then the value in the HOURS WORKED array for that week was set to zero; previously, a subtraction was performed.
3. Before these changes, some cases had negative hours (not including missing value codes) in some of the weeks in the HOURS WORKED array. Now, all of the values in the HOURS WORKED array are positive except for the standard missing values. These changes resulted in an overall decrease in the number of hours reported in a given week and in the number of hours calculated for the last calendar year and since the date of the last interview for those cases that were affected.

The following table lists the key variables for each year that had a change in values and the number of cases that had a change in the calculation of that key variable between the 1979-87 work history creations and the previous years.

TABLE 1: Cases Changed by 1987 Work History Program

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Changes between the 1979-87 and the 1979-88 Work History Data File

Most changes made to the work history program between the 1979-87 and 1979-88 data files did not affect the content of the variables themselves. Some changes were made to simplify the reading and use of the program in the future. Format changes were also made to allow for larger variable lengths. Because 1988 is the 10th year of the NLSY79, variables such as a job number, which provided only one space for the survey year, were expanded. The DUAL JOB array was no longer concatenated. Instead, four variables are present for each week, allowing (as before) for up to four dual jobs per week.

Substantive changes are not major and are a function of changes in the questionnaire:

1. GOVTJOB in 1988 is set to valid missing for all respondents. This question was dropped from the survey.
2. HOURSWEEK in 1988 also includes additional hours worked at home if any are reported. The 1988 questionnaire asked respondents separately about hours worked at home for a job. If any hours worked at home were reported, respondents were asked if their total hours worked per week included those hours worked at home. If not, the total hours worked per week and the hours worked at home were added together to get a total number of hours worked per week anywhere for a job.

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Changes between the 1979-88 and the 1979-89 Work History Data File

Several additions were made to the variable structure for the 1979-89 work history data file. These changes did not affect the content or substance of already existing variables.

1. A JOBSEVER variable was created for each year from 1979-89. This variable is a cumulative count of the number of different jobs that have ever been reported by a respondent up to the date of interview for the survey year. Users should note that, as with calculations for the TENURE variables discussed earlier in this program description, employers can only be traced through contiguous years. In non-contiguous years, the number of jobs reported may be slightly inflated in some cases.
2. SEX and RACE variables have been added to the work history stratifications by sex and race for all respondents. The SAMPLE_ID variable remains in the dataset for those requiring further sample delineation.

Some data changes have been made in existing variables as well. Two of these reflect corrections that have been made in the calculations for 1987 and 1988 variables.

1. The WEIGHT variable for each year has been recoded for non-interview cases from -5 to 0. This recoding makes these weight variables consistent with those found in the main data set.
2. The 1987-88 TENURE variables were in error in the 1979-87 and 1979-88 work history releases. An error in the program statements which calculate this variable resulted in large numbers of respondents with valid values receiving -3 values instead. This error has been corrected and the changes have been incorporated in the current release.
3. In the 1979-88 work history release, the HOURSWEEK variable was to include additional hours worked at home on a job, if reported. Although this was true for JOBs #6-10, the necessary programming changes for JOBs #1-5 were inadvertently omitted from the program. Therefore, JOBs #1-5 were calculated as they have been in previous work history programs, based upon one question without qualification for any additional hours worked at home. The omission has been corrected and the changes have been incorporated in the current release.
4. In 1988, 116 cases reported a 3^rd within-job gap for at least one job. The information for these gaps was erroneously included as information for a 4^th within-job gap. The 3^rd within-job gaps for these cases would have been missing. This has been corrected in the 1979-89 release. Additionally, information on a 4^th within-job gap for at least one job has been included for 18 cases.

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Changes between the 1979-89 and the 1979-90 Work History Data File

A minor modification was made to the HRP PROC (the procedure at the end of each year's program which calculates HOURLYWAGE from PAYRATE and TIMERATE). Any PAYRATE which has a value of 9999995 is now set to -4 by the HRP PROC. This 9999995 value indicates a case for which the dollars and cents PAYRATE exceeded $100,000.00.

Some data updates were made to existing variables as well. Users have already been notified of the erroneous data for affected cases with the release of the 1989 main NLSY79 and work history data files, and in the Summer 1991 (No. 68) issue of NLSUPDATE.

1. Specific job information for 70 cases was edited, for one or more jobs, due to improper identification of CPS jobs in the Employer Supplements.
2. Corrections were made to 23 cases for 1988 PAYRATES and/or 1988-89 HOURLYWAGEs. These cases exceeded $100,000.00 and should have been assigned the 9999995 value. While some contained that value, some retained an erroneous dollars and cents value in PAYRATE. In either case, the HOURLYWAGEs were calculated based upon an incorrect PAYRATE figure. The above-mentioned adjustment to HRP PROC will prevent the calculation of HOURLYWAGE figures from the truncated 9999995 value in the future.

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Changes between the 1979-91 and the 1979-92 Work History Data File

A change has been made to the structure of the 1979-92 work history data file on magnetic tape only. Due to the volume of the current work history data file, the data were split into two records. The first record contains the data for the STATUS, HOURS and DUALJOBS arrays. The second contains the remainder of the data, pertaining to specific job characteristics, gaps in employment and summary labor force activity variables. Those wishing to use only job specific variables can now do so without being required to process information for an entire case to do so. Those wishing to incorporate the arrays in analysis can access them in a separate record. Tape users should refer to the record layout and format table provided in this package of documentation for details on the exact location of each variable. This change does not affect the content or substance of already existing variables.

A correction was made to an existing set of variables as well. Users have already been notified of the inadvertent omission of hourly rates of pay for those respondent reporting earnings on a semi-monthly basis in the 1990 and 1991 main NLSY79 and work history data files, and in the Winter 1993 (No. 74) issue of NLSUPDATE. These cases have been corrected in the 1979-92 version of the work history data file.

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Changes between the 1979-92 and the 1979-93 Work History Program

Changes occurring between these releases were not substantive. Adjustments made for both the size of the data file and to accommodate the CAPI-collected data were necessitated in the work history program and will only be noticeable to those reviewing the actual 1993 work history program, included in the 1979-93 work history documentation. Users examining the program will find three types of changes:

1. Due to the size of the work history data file, it is prohibitive to maintain an in-house CHRR data file with 10 jobs, from which the five-job public tape is then produced. Instead, the previous year's public release, containing data on five jobs only, is used to create the base data file for past survey years. The current survey data is appended to the 5-job file. A 10-job working data file is then created in the course of the work history program, ONLY for the current year's data, to allow created variables being calculated for the current survey year to incorporate data from up to 10 jobs. Detailed information on only the first five jobs is retained for the current release.
2. The work history program previously required a separate data set for data on additional job gaps (beyond the first three within-job gaps and first four between-job gaps). This extra data file is no longer necessary. The CAPI data file contains all data (except weights, which are added from a different source), necessary to produce the work history data file.
3. Beginning with the 1979-93 release, the formats for the PAYRATE variables have been extended to 8 characters to accommodate values up to 99999999 ($999999.99). Previously, these cases containing these variables had been assigned a PAYRATE value of 9999995 and set to -4 in the HRP PROC, which creates the HOURLYWAGE variables. Valid PAYRATE and HOURLYWAGE values are now present in these cases.

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Changes between the 1979-93 and the 1979-94 Work History Data File

The recall experiment (an experiment to test the recall of respondents over a two year period) was conducted with over 850 randomly selected respondents during the 1994 interview. For this experiment, respondents were treated as if the 1993 interview never took place; the interview was conducted as if the 1992 interview was the most recent. Because data from 1993 were already incorporated into the work history data file, we sought to keep redundant data from the 1994 interview for the "recall" cases from overwriting the already incorporated 1993 data. Efforts were made to eliminate the overlap between the information reported in 1993 and 1994 for those cases, and to keep only the information from the 1994 interview that covered the period since the 1993 interview. However, there were isolated circumstances in which this was not possible. These relate to the assignment of "OLF" versus "unemployed" labor force status during periods not working which contain both types of statuses (see earlier discussion in this document). While it is possible to determine which part of a period not working occurred since the 1993 interview, it is not possible to make the same determination for "OLF" versus "unemployed" status during those periods. Therefore, it is likely that in some cases these statuses would not have been assigned correctly to certain periods not working. See Appendix 16 in this codebook supplement document for further details on the recall experiment.

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Changes between the 1979-94 and the 1979-96 Work History Data File

Through survey year 1994, the work history data file was created by running PL/I programs on an IBM mainframe. In 1996, the volume of the work history data file dictated a change to a more efficient method of production. To create the 1979-96 data file, the PL/I program was converted to SQL code. Relevant variables from the main NLSY79 data file were loaded into a relational data base, from which the work history data file was generated. The SQL code that generated the data file replicates the PL/I program, both in substance and function.

No revisions were made to the 1979-94 job-specific data created by the PL/I programs in past rounds. For respondents with missing interviews between the last interview and 1996, the STATUS, HOUR and DUAL JOB arrays were updated by the SQL program in the same manner as in past years with the PL/I programs.

Although the SQL programs are not included in this appendix, the separate addendum contains the PL/I programs from past years. A list of the main NLSY79 variables used in the creation of the 1979-96 work history data set is included at the end of this appendix.

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Changes between the 1979-96 and the 1979-98 Work History Data File

For the first time with the 1979-98 work history release, Windows-based extraction software accompanied the data file.

Users should be aware that the TENURE variable for job #2, reported in 1980, was found to be in error on the 1979-96 work history release only. This variable has been replaced with the correct data on the 1979-98 work history release.

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Changes between the 1979-98 and the 1979-2000 Work History Data

The round 19 combined main youth-work history release marks the first time that the work history data are being released in combination with the main NLSY79 data. Data items formerly available only in a separate work history data file, including the week-by-week arrays, are now available in a series of new areas of interest on the public release CD, using the same extraction software as the main NLSY79 data. This eliminates the need for multiple extracts and merging of data from different CDs, as well as the duplication of some information specific to individual jobs and respondents between data files.

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Changes between the 1979-2000 and the 1979-2002 Work History Data

The round 20 (2002) Employer Supplements underwent some significant revisions to better accommodate respondents reporting self-employed and non-traditional (temporary, contracting, on-call, etc.) types of employment situations, as well as teaching occupations. Many adjustments involved asking comparable or consistent questions with wording more appropriate to the type of employment being reported. These additional questions have been incorporated wherever necessary in the construction of the Work History data to produce variables consistent with those produced historically. Relevant questions names are noted in the discussions below.

The 2000 Census Industry and Occupation Classifications were used to code the 2002 NLSY79 data. Industry and occupation codes contained in the 1979-2000 main file and Work History data were 1970 codes, with 1980 codes being assigned to the current/most recent job for the respondent only.

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DESCRIPTION AND CODES FOR VARIABLES IN 1979-2004 NLSY79 WORK HISTORY DATA

For the first time on the 2000 (round 19) public release CD, the work history file was combined with the other NLSY79 data. This eliminates the need for multiple extracts and merging of data from different CDs, as well as the duplication of some information specific to individual jobs and respondents. Below is a listing of items which formerly comprised the separate work history data file and their disposition on the combined NLSY79 2004 CD. Variable coding information, as well as formulas for combining job-specific characteristics from several sources, are included where relevant.

Work history weekly array variables

The foundation of the work history data file is the set of week-by-week arrays depicting labor force status, total number of hours, and dual job holdings if any, for each week since January 1, 1978. These array variables are now found in three new areas of interest on the combined main-work history NLSY79 release. The construction and coding for each of the three arrays are described below, listed by their new area of interest.

Area of interest: WORK HISTORY-WEEKLY LABOR STATUS

The WEEKLY LABOR STATUS array is the work history week array. Each variable corresponds to a week relative to 1/1/78.^[1] There are 1,426 variables in the 1979-2004 WEEKLY LABOR STATUS array--one for each of the 1,426 weeks from 1/1/78 to 4/24/05.^[1] There are no missing data codes, and the codes that are in the array are as follows:

Area of interest: WORK HISTORY-HOURS WORKED

The HOURS WORKED array contains the usual hours worked per week at all jobs. There are 1,426 variables in the 1979-2004 HOURS WORKED array--one for each of the 1,426 weeks from 1/1/78 to 4/24/05.^[2] The codes are as follows:

Area of interest: WORK HISTORY-DUAL JOBS

The DUAL JOBS array contains job numbers for any weeks when the respondent worked at more than one job. There are 4,258 variables in the DUAL JOBS array - up to four for each of the 1,426 weeks from 1/1/78 to 4/24/05.^[2] DUAL JOBS array variables are present if a dual job was reported. The variables are written in the following order (by week and then by job)^[3]:

• Week 0 < 1/1/78, Job # 1
• Week 0, Job # 2
• Week 0, Job # 3
• Week 0, Job # 4
• Week 1, Job # 1
• Week 1, Job # 2
• Week 1, Job # 3
• Week 1, Job # 4

etc.

The codes are as follows:

For example, if a respondent worked at three jobs at the same time, the code for the lowest job number would be in the WEEKLY LABOR STATUS array, and the codes for the other two jobs would be in the DUAL JOBS array (see item 3 in the user notes below). If the three jobs that the respondent held during week 190 from the 1981 survey were jobs 1, 5, and 6, then WEEKLY LABOR STATUS would contain the value '301' for that week, and two DUAL JOBS array variables for week 190 would contain the values '305' and '306'.

Non-array work history variables

The variables listed below have traditionally been included on the work history data file only. On the combined main-work history release, these variables are now contained in one of several new work history areas of interest. They are listed below by new area of interest. Variables marked with an asterisk (*) contain an actual consecutive week number, ranging from week number 0-1426, with the week of January 1, 1978, being week #1. Week #0 represents information for time prior to that date.

Area of interest: WORK HISTORY-HISTORY

Area of interest: WORK HISTORY-CALENDAR YEAR

Area of interest: WORK HISTORY-JOBS

Area of interest: WORK HISTORY-GAPS BETWEEN JOBS

Area of interest: WORK HISTORY-SINCE LAST INTERVIEW

Area of interest: WORK HISTORY-MILITARY

Variables created by the work history programs included in NLSY79 main data file

The work history programs produced a set of variables each year that were included both on the separate work history data file and the NLSY79 main data file. In the combined main-work history data release, these items are found in their traditional place among public release data items. They are listed below, with an example reference number for the most current year for each variable in parentheses.

Variables picked up from NLSY79 main data file

The separate work history data file contained a large number of duplicated items pertaining to jobs, job gaps, and the individual respondents that were copied straight from the main data file. On the combined main-work history data release, these items can be found in their traditional place among public release data items. They are listed below by type of variable. Example reference numbers for the most current year for each variable are listed in parentheses.

Variables compiled from NLSY79 main data variables

Some variables in the separate work history data files were created from multiple variables in the main data file. They are listed below, along with the items that were used to compile them in the most recent year available.

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WORK HISTORY PROGRAMS

The PL/1 program used to create the work history variables through 1994 is available to researchers. This program can be examined by those who desire details about the creation of the work history variables not included elsewhere in this appendix. Due to the length of this program, it is not printed in this document. It is provided only in electronic form. Users interested in obtaining this "Addendum to Appendix 18" should contact NLS User Services (see the cover of this codebook supplement for contact information).

Note: To view an Adobe Acrobat PDF version of this file, click here. If you are viewing this HTML file in the NLS Investigator program, you may need to open it in a Web browser to follow this link.

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VARIABLES USED IN CREATION OF 1996 AND SUBSEQUENT WORK HISTORY DATA FILES

Beginning in 1996, the work history variables were created using a new SQL program. The SQL program, which mirrors the older PL/1 program, is not available to users. However, the following pages list the variables used as inputs to the SQL program. Users who need more information should contact NLS User Services.

Users should be aware that not all of variables listed below appear in the main NLSY79 data file. Variables with no valid data for any respondent, jobs 6-10, within-job gap 4 and between-job gaps 5-6 are not currently included in the main file.

1996 Work History Input Variables

/* The following variables were loaded into a relational data base and used as direct input for creation of the 1979-96 Work History data file.*/

1998 Work History Input Variables

/* The following variables were loaded into a relational data base and used as direct input for creation of the 1979-98 work history data file.*/

2000 Work History Input Variables

/* The following variables were loaded into a relational data base and used as direct input for creation of the 1979-2000 work history data file.*/

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2002 Work History Input Variables

/* The following variables were loaded into a relational data base and used as direct input for creation of the 1979-2002 work history data file.*/

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2004 Work History Input Variables

/* The following variables were loaded into a relational data base and used as direct input for creation of the 1979-2004 work history data file.*/

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Endnotes

^[1] All week number references in this program are relative to 1/1/78 and end with the most recent interview date. A week #0 is included at the beginning of the week-by-week array structures to indicate ti