Age

Created Variables

AGEATINTERVIEW - These variables provide the respondent’s age at each interview date.

Important Information About Using Age Data:

The eligibility for inclusion in this cohort was based on the 1979 age reports, as are weights.

Birth date questions were asked again in the 1981 survey because: 

  1. a number of discrepancies between birth dates found on the military file and the NLSY79 files were discovered. 
  2. a number of inconsistencies between age as recorded on the "Household Enumeration" and the main questionnaire were apparent. 

The 1981 birth dates should be used to determine age with the 1979 dates used only as a backup.

Differences between 1979 and 1981 birth dates remained for approximately 200-250 respondents after the 1981 fielding; editing on a case-by-case basis was performed by CHRR staff on only the 1981 variable.

Inconsistencies in age or birth date information may appear for a number of reasons:  age and birth date information has been collected at multiple survey points, giving rise to respondent-reported inconsistencies; respondents' ages for sample selection were based on date of birth information reported at the time of the 1978 household screening by individuals who may not have been the respondent; and responses to interviewer check items, that is, the age reported to the interviewer that determines when age-specific questions should be asked, may not be the same age as that calculated from previously reported age or birth date information.  For example, a respondent whose age was 16 as calculated from the birth date reported in 1981 may have answered questions which were specific to a 17 year old. 

Data collected:

Table 1 depicts age distributions of the NLSY79 for the 1979-2008 survey years.  The two tables use the created variable 'Age of R at Interview Date.'

Table 1 Age Distribution of Respondents on Day of Interview (Unweighted Data)

Year

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

96

98

00

 02 04  06  08 

Fielding Period (Months)

Age

1-8

2-5

2-5

2-5

2-5

2-5

2-5

2-5

5-10

6-12

6-12

6-12

6-12

5-11

5-11

6-12

4-10

3-10

5-12

 1-12 1-12 1-12 1-12

Not Int

  

545

491

563

465

617

1792

2031

2201

2221

2081

2250

3668

3670

3675

37971

4050

4287

4653

 4962 5025 5032 4929

14

948

                                            

15

1566

977

                                          

16

1564

1532

986

                                        

17

1505

1510

1528

975

                                      

18

1634

1462

1505

1504

1002

                                    

19

1677

1551

1485

1515

1515

989

                                  

20

1667

1603

1585

1484

1505

1488

971

                                

21

1682

1583

1620

1561

1510

1498

1492

869

                              

22

433

1576

1592

1617

1566

1487

1492

1417

593

                            

23

  

347

1600

1578

1657

1550

1443

1468

1420

280

                          

24

    

294

1596

1582

1626

1429

1409

1459

1391

395

                        

25

      

293

1621

1583

1351

1426

1378

1448

1425

285

                      

26

        

263

1578

1245

1330

1418

1397

1461

1382

339

                    

27

          

270

1248

1222

1338

1405

1410

1405

1200

318

                  

28

            

223

1208

1188

1355

1394

1420

1306

1207

383

                

29

              

306

1199

1194

1374

1358

1265

1310

1204

276

              

30

                

492

1215

1218

1385

1231

1247

1307

1198

              

31

                  

779

1235

1197

1165

1256

1258

1291

425

            

32

                  

1

693

1212

973

1137

1242

1222

1172

            

33

                      

792

1000

992

1153

1240

1235

450

          

34

                        

539

984

964

1155

1200

1141

          

35

                          

565

1002

951

1183

1204

287

        

36

                            

498

982

1093

1167

1054

        

37

                              

574

909

1155

1165

 337      

38

                                

973

1056

1096

 1050      

39

                                

446

897

1108

 1110 159    

40

                                  

930

1032

 1072 934    

41

                                  

399

868

 1082 1078 482  

42

                                    

888

 981 1055 1030  

43

                                    

534

 830 1094 1122 552

44

                                    

1

 833 980 1041 1054

45

                                      429 863 1088 1107
46                                         834 958 1085
47                                         659 821 1079
48                                         5 827 974
49                                           283 815
50                                           2 834
51                                             256
52                                             1
 

1  Two respondents had missing values for date of interview; therefore, age at interview date cannot be calculated.  These respondents are included in the noninterview category.

Age Restrictions on Early Work Experience Data:  In the early survey years, some restrictions were imposed on data collected on work experience, specific employers, and military service.  These restrictions applied, for the most part, to those respondents under the age of 16 at the time of the 1979 survey, although some extend beyond that age.  The following is a summary of age restrictions that can be found in the work and job experience sections of the 1979 questionnaire.

Area Restrictions
Military Those respondents 16 years and under at the 1979 and subsequent interviews were skipped past all military service questions.  This age group was only asked three questions concerning attitudes on service in the military and the possibility of enlistment in the future (Q.72-Q.74).  Variables from this section are found in the "Misc. 1979" area of interest, and for subsequent years, in both the "Misc. xxxx" and "Military" areas of interest.
On Current Labor Force Status
(CPS Questions)		 Those CPS questions concerning activity most of the survey week and CPS job (Q.1-Q.36) were asked of all respondents.  However, those respondents ages 15 or younger were not asked the questions dealing with looking for work.  Questions in this section are found in the "CPS" and "Misc. xxxx" areas of interest.
On Jobs Information on school-related jobs is collected for 14- and 15-year-olds.  School-related job information is also collected for other respondents who were not employed since 1978 and who were enrolled in regular school at some time since January 1, 1978.  For those 16 years and older, information on all jobs since January 1, 1978, was collected.  For all respondents, information was gathered on enrollment in various types of government-sponsored programs that provided jobs.  These variables can be found in the "Jobs" and "Misc. 1979" areas of interest.
Jobs (Employer Supplements, in subsequent survey years)

For the first job listed (which should be the CPS job), 14-15 year olds were routed through the entire series of questions, regardless of whether the job was a government-sponsored job.  For each additional job that was not government-sponsored, 14 and 15 year olds were asked only a basic set of questions about start/stop dates, reasons for leaving (if applicable), and hours worked per week.  For each additional job that was government-sponsored, all applicable information was gathered, regardless of the age of the respondent.

These variables can be found in the "Job Information," "Government Jobs," and "Misc. 1979" areas of interest.  Users should keep in mind that some of the information contained in the "Job Information" variables will refer to government-sponsored jobs (and possibly school-related/work-study jobs), as general information was collected on these jobs as well.
On Last Job Lasting 2 Weeks or More Information is regularly collected on the last job held.  There is no age restriction.  These questions can be found in the "Jobs before 1978" area of interest.
On Work Experience Prior to January 1, 1978 If the respondent was 19 years or younger at the time of the 1979 interview, he or she would have been under 18 before 1978, so the retrospective information for the time period prior to 1978 was not collected.  However, respondents not enrolled in regular school at any time between January 1978 and the interview date, regardless of age, were asked about the first job they held for two or more months at which they worked 20 hours a week or more after they stopped attending school.  Variables from this section are found in the "Jobs after School" area of interest.

On Government Training

All respondents enrolled in grades 1-12 are skipped over this entire section.

Comparison to Other NLS Cohorts

Age data are available for all NLS cohorts.  These variables include both the age of the respondents as of a fixed date during the initial survey year and as of the interview date in various years.  Date of birth is also available for all cohorts.  Consult the BLS website at www.bls.gov/nls or the appropriate cohort's User's Guide for information about accessing these data.