work history data

Work History Data

1. Overview the key employment-related work history variables in the NLSY79 and NLSY97.

2. Examine selected work history variables for one NLSY79 respondent to see how his employment activities are summarized.

3. Consider alternative ways to measure work experience and job mobility.

Part 1

Overview of Employment-Related

Work History Variables in the

NLSY79 and NLSY97

A. NLSY79 & NLSY97 Weekly Arrays

Definition NLSY79 QName NLSY97 QName

Labor force status:

STATUS_WK_NUMxxxx EMP_STATUS.year.wk

Hours worked per week:

HOURS_WORKED_ WK_NUMxxxx

EMP_HOURS.year.wk

Dual job status: JOB_WK_NUMxxxx_ DUALJOB_NUMx

EMP_DUAL_x_year.wk

• Each array contains one variable per week • Week 1 begins on January 1, 1978 in the NLSY79

B. Other Employment Variables (NLSY79 & NLSY97)

Definition NLSY79 QName NLSY97 QName

Start date (job) START_WK#_year

_JOB#n

EMP_START_WEEK_syr.job#

EMP_START_YEAR_syr.job#

Stop date (job) STOP_WK#_year

_JOB#n

EMP_END_WEEK_syr.job#

EMP_END_YEAR_syr.job#

Start date

(within-job gap)

PER#_START_year

_JOB#

EMP_GAP_START_WEEK

_syr.job.gap

EMP_GAP_START_YEAR

_syr.job.gap

Stop date

(within-job gap)

PER#_STOP_year

_JOB#

EMP_GAP_END_WEEK

_syr.job.gap

EMP_GAP_END_YEAR

_syr.job.gap

B. Other Employment Variables (NLSY79)

Definition Survey

Years

NLSY79 QName

Start date (period not working between jobs)

All BSTART_year_PERIOD#

Stop date (period not working between jobs)

All BSTOP_year_PERIOD#

Start date (military service) All MIL_START#_year

Stop date (military service) All MIL_STOP#_year

Week of the current interview: All CURRINT__WK#_year

Week of the last interview: All LASTINT__WK#_year

Job number assigned to employer from last interview:

All PREV_EMP#_year_JOB#n

B. Other Employment Variables (NLSY97)

Definition Survey Years

NLSY97 QName

Number of weeks prior to DLI in which the EMP_STATUS.year.wk variable would have changed had this job been included in the last interview.

2000+ EMP_BK_STATUS_syr

Number of weeks prior to DLI that job began.

2000+ EMP_BK_WKS_syr

Number of hours prior to DLI that would have been included in the EMP_HOURS.year.wk array had this job been included in the last interview.

2000+ EMP_BK_HOURS_syr

Part 2

Examine Selected Work History Variables for one NLSY79

Respondent

Our Respondent

• We will follow a single NLSY79 respondent (CASEID=15) from 1990 to 1993.

• The examples show how selected work history variables convey this respondent’s employment activities.

A. Job Start Dates and Stop Dates

1990 interview CURRINT_WK#_1990 = 658

1990 interview is held the week of 8/5/90 (week 658).

START_WK#_1990_JOB#n = . (for n=1,2,3,4,5)

STOP_WK#_1990_JOB#n = . (for n=1,2,3,4,5)

The respondent reports no current job, and no jobs

held since the last interview.


1991 interview is held the week of 6/30/91 (week 705).

START_WK#_1991_JOB#01 = 674

STOP_WK#_1991_JOB#01 = 705

The respondent reports a job that began in week 674.The job does not “stop” in week 705. The interview

week is used as a pseudo-stop week to indicate that the job is ongoing. [A variable in the Job Information file confirms that the respondent is currently working for this employer.]

In this example, we will refer to this job as Job A.

START_WK#_1991_JOB#n = . (n=2,3,4,5)

STOP_WK#_1991_JOB#n = . (n=2,3,4,5)

The respondent reports no other jobs held since the last interview.

Based on this reported information we know that, as of week 705, the respondent’s work history looks like this:

658 674 705

Job A begins1990 interview 1991 interview (Job A in

progress)

1992 Interview CURRINT_WK#_1992 = 755 LASTINT_WK#_1992 = 706

1992 interview is held the week of 6/14/92 (week 755).LASTINT_WK is last year’s interview week +1.

PREV_EMP#_1992_JOB#01 =1 START_WK#_1992_JOB#01 = 706 STOP_WK#_1992_JOB#01 = 755

The “previous employer” variable indicates that this year’s job #1 is identical to last year’s job #1.

We continue to refer to this job as Job A.

1992 Interview, continued PREV_EMP#_1992_JOB#01 =1

START_WK#_1992_JOB#01 = 706

STOP_WK#_1992_JOB#01 = 755

Job A does not “start” in week 706. The last interview week is used as a pseudo-start week to indicate that this job is a continuation of a job reported last year.

Job A does not “stop” in week 755. The interview week is used as a pseudo-stop week to indicate that the job is ongoing.

START_WK#_1992_JOB#n = . (n=2,3,4,5)

STOP_WK#_1992_JOB#n = . (n=2,3,4,5)


As of week 755, the respondent’s work history looks like this:

Job A begins

1990 interview 1991 interview

658

1992 interview(Job A in progress)

755674 705

1993 Interview CURRINT_WK#_1993 = 810 LASTINT_WK#_1993 = 756

1993 interview is held the week of 7/4/93 (week 810).LASTINT_WK is last year’s interview week +1.

PREV_EMP#_1993_JOB#02 =1 START_WK#_1993_JOB#02 = 756 STOP_WK#_1993_JOB#02 = 767

The “previous employer” variable indicates that this year’s job #2 is identical to last year’s job #1.

Job A does not “start” in week 756. The last interview week is used as a pseudo-start week to indicate that this job is a continuation of a job reported last year.

Job A ended the week of 9/6/92 (week 767); this is the job’s true stop date.

1993 Interview, continued START_WK#_1993_JOB#01 = 771

STOP_WK#_1993_JOB#01 = 810

The respondent reports a new job that began the week of 10/4/9 (week 771).

In this example, we refer to this new job as Job B.

Job B does not “stop” in week 810. The interview week is used as a pseudo-stop date to indicate that the job is ongoing.

START_WK#_1993_JOB#n = . (n=3,4,5)

STOP_WK#_1993_JOB#n = . (n=3,4,5)


As of week 810, his work history looks like this:

Job A begins

1990 interview

1991 interview

658 674 705

1992 interview

755 767

Job A ends

Job Bbegins

771 810

1993 interview(Job B in

progress)

A. Job Start Dates and Stop Dates

• Users may wish to create their own variables identifying the “true” start week and stop week of each job held

• For example, we might create the variables:

STARTx = start week of job x, where x indexes the 1st through

last job encountered in chronological order

STOPx = stop week of job x

CENx = 1 if job x is right-censored (in progress when the

respondent is last interviewed) and 0 otherwise

• If our respondent (CASEID=15) were only seen from 1990 to 1993, these variables would take on the following values:

START1=674 START2=771

STOP1=767 STOP2=810

CEN1=0 CEN2=1

Note: If we begin following this respondent in 1979,

Job A is not his first job. Similarly, if we follow him

beyond 1993, Job B is followed by several

additional jobs.

• For additional information, see: NLSY79 APPENDIX 9: “LINKING EMPLOYERS THROUGH

SURVEY YEARS”

• The respondent’s weekly labor force status is described

by the array of variables named STATUS_WK_NUMxxx

• These variables can take on the following values:

0: no information reported for week

2: not working (unemployed vs. OLF not determined)

3: associated with employer (gaps missing; time

unaccounted for)

4: unemployed

5: out of labor force (OLF)

7: active military service

xxnn: employed (xx is round; nn is job number)

B. Weekly Labor Force Status

1990 interview CURRINT_WK#_1990 =658

STATUS_WK_NUM647 – STATUS_WK_NUM654 = 4


The respondent is interviewed in week 658.

He is OLF at the interview date.

This 4-week OLF spell is preceded by an 8-week unemployment spell that began in week 647.

As we will learn “next year,” this period of unemployment/OLF will continue for several more weeks.





“Last year’s” period of unemployment/OLF continued through week 673.

Recall that he is now holding a job (Job A) that began in week 674.

The status array shows that from week 674 to the current interview week, he is employed on Job A, which is job #1 reported in 1991 (r13).




Recall that he has worked continuously on Job A since the last interview date.

The status array shows that from the last interview week to the current interview week he is employed on Job A, which is job #1 reported in 1992 (r14).

1993 interview CURRINT_WK#_1993 =810 STATUS_WK_NUM756 – STATUS_WK_NUM 767 = 1502 STATUS_WK_768 – STATUS_WK_NUM770 = 4 STATUS_WK_771 – STATUS_WK_NUM810 = 1501

Recall that Job A ended in week 767 & Job B began in week 771.

The status array shows that from the last interview week to week 767 he is employed on Job A, which is job #2 reported in 1993 (r15).

The status array shows that from week 771 to the current interview week he is employed on Job B, which is job #1 reported in 1993 (r15).

The status array shows that he was unemployed for the 3 weeks between Job A and Job B.

With the addition of the information in the status array, we

know that this portion of the work history looks like this:

658 674 705 755 767 771 810647

Job A

1990 interview

1991 interview

1992 interview

Job B

1993 interview

UnemploymentUnemployment or OLF

C. Weekly Hours Worked

• The respondent’s weekly work effort is described by the array of variables: HRS_WORKED_WK_NUMxxxx

• These variables give the usual weekly hours worked on all jobs during the particular week.

1990 interview CURRINT_WK#_1990 =658

HRS_WORKED_WK_NUM647 – HRS_WORKED_WK_NUM658 = 0


Recall that the respondent is unemployed or OLF from week 647 to week 658 (and beyond).

The hours array shows that he work zero hours during each week of the unemployment/OLF spells.





The hours array shows that he worked zero hours for the duration of “last year’s” unemp/OLF spell.

Recall that the respondent began Job A in week 674.

When interviewed in week 705, the respondent reports his “usual weekly hours” on Job A to be 50.

The hours array shows 50 hours for every week since Job A began.




Recall that the respondent has worked on Job A since the last interview.

When interviewed in week 755, the respondent reports his “usual weekly hours” on Job A to be 55.

The hours array shows 55 hours in every week since the last interview.





When interviewed in week 810, the respondent reports his “usual weekly hours” on Job A (which ended in week 767) to be 50.

When interviewed in week 810, the respondent reports his “usual weekly hours” on Job B (which began in week 771) to be 40.

The hours array shows that he worked zero hours during each week of the intervening unemployment spell.

Part 3:

Measuring Work Experience and Job Mobility

Examples from the NLSY79 (and YA)

A. Cumulative Work Experience • In cross-sectional surveys, data on actual work

experience are scarce.

• As a result, we often use “Age-Schooling-6” as a proxy for work experience. At the interview date, the respondent reports his age

and years of schooling (S).

We approximate his school exit date as age S+6 and his experience as the time elapsed since that date.

Born Assumed to begin school

Assumed to end school

Interviewed (report age & S)

6 yrs S yrs Age-S-6 yrs

• With NLS data, we have many options for measuring work experience.

We need not “start the clock” on work experience at age S+6. We can pick any date as the starting date (t1).

We can also pick any date as the stopping date (t2).

We need not measure experience as “elapsed time.” Instead, we can count the number of weeks actually worked, the (usual) number of hours worked, etc.

Defining t1 and t2:

• Depending on one’s substantive focus, possibilities include:

Let t1 be the actual date of school exit (e.g., first exit, last exit, or

first exit lasting at least N months)

Let t1 be the date of college entry and t2 be the date of college exit;

this allows us to measure work experience gained while in college.

Let t1 be a particular age (e.g., the 18th birthday). This allows us

to measure all respondents’ work experience from a uniform date regardless of their school enrollment behavior.

Let t1 be the job start date and t2 be the job stop date. This allows

us to measure experience with a particular employer.

Born Begin school Actual school exit date (t1)

S1 yrs S2 yrs

Break from school

Defining the unit of measurement:

• Possibilities include:Cumulative number of months (or 4-week intervals)

in which any experience was gained.

Cumulative number of weeks in which any

experience was gained.

Cumulative number of weeks in which the individual

worked full-time (e.g., usual hours35).

Cumulative number of (usual) hours worked.

Example 1 • Define EXPER1 = cumulative weeks between t1 and t2 in

which any experience was gained.

• LFS1-LFS1409 are variables containing elements of the array STATUS_WK_NUMxxx for weeks 1 (1/1/78) through 1409 (12/26/04).

• T1 and T2 are the start and stop weeks between which

we wish to measure work experience; array status (1409) LFS1-LFS1409;

EXPER1=0;

do k=T1 to T2;

if status(k)>7 then EXPER1=EXPER1+1;

end;

EXPER1=EXPER1/52;

Note: this strategy counts military service and “unknown” weeks as 0.

Example 2

• Define EXPER2= cumulative hours worked between t1

and t2

• HRS1-HRS1409 are variables containing elements of the

array HOURS_WORKED_WK_NUMxxxx for weeks 1

(1/1/78) to 1409 (12/26/04)

• T1 and T2 are the start and stop weeks

array hrs (1409) HRS1-HRS1409;

EXPER2=0;

do k=T1 to T2;

if hrs(k)>0 then EXPER2=EXPER2+HRS(k);

end;

EXPER2=EXPER2/2000;

Note: this strategy counts “unknown” weeks as HRS=0.

Example 3 • Define JOB= 1 if a job is held at t1; JOB=0 otherwise.

(In contrast to the preceding examples, this is not a measure of cumulative experience.)

• START1-STARTX and STOP1-STOPX are user-created variables representing the start and stop dates of every job held.

To make the example concrete, assume X=40 (i.e., 40 is the maximum number of jobs reported by any R).

• T1 is the date of interest (e.g., a given age).array STARTS (40) START1-START40;array STOPS (40) STOP1-STOP40;JOB=0;

If T1>0 then do k=1 to 40;if STARTS<=T1<=STOPS then JOB=1;

end;

Example 3, continued Let T1 be the week of the 20th birthday

Compare JOB for NLSY79 mothers & their YA daughters

Mother holds job at age 20

No Yes All

No 1074

(71%)

437

(29%)

1511

(69%)

Yes 419

(62%)

257

(38%)

676

(31%)

All 1493

(68%)

694

(32%)

2187

Daughter holds job at age 20

B. Cumulative Number of Jobs Held

We may wish to measure:

• Cumulative number of jobs begun between any two

points t1 and t2 (e.g., from school exit to the interview

date).

• Cumulative number of jobs ended between any two

points t1 and t2

• Cumulative number of job-to-job transitions between

any two points t1 and t2

Example 4

• Define JOBBEG = # of jobs begun between t1 and t2

• Define JOBEND = # of jobs ended between t1 and t2

• START1-STARTx and STOP1-STOPx are user-created variables representing the start and stop dates of every job held; CEN1-CENx are user-created variables equal to 1 if the job is right-censored, and 0 otherwise.

To make the example concrete, assume x=40; i.e., 40 is the maximum number of jobs reported by any respondent.

T1 and T2 are the start and stop weeks between which we will obtain our job count.

Example 4, continued

array STARTS (40) START1-START40;

array STOPS (40) STOP1-STOP40;

array CENS (40) CEN1-CEN40;

JOBBEG=0; JOBEND=0;

do k=1 to 40;

if T1<=STARTS(k)<=T2 then JOBBEG=JOBBEG+1;

if (T1<=STOPS(k)<=T2 and CENS=0) then

JOBEND=JOBEND+1;

end;

work history data

Documents

week week

years job

current job

job gapper

job mobility

wkdual job status

years interview week

job information file