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National Longitudinal Survey of Youth 1979 (NLSY79)

Retention & Reasons for Noninterview

Retention vs. Response Rate

Retention rates for NLSY79 respondents from 1979 to 1993 exceeded 90 percent. Rates from 1994 until 2000 exceeded 80 percent. Rates from 2002 until 2014 were in the 70s. Retention rate is calculated by dividing the number of respondents interviewed by the number of respondents remaining eligible for interview. All 1979 (round 1) respondents including those reported as deceased are eligible for interviews, with the exception of those who have been permanently dropped from the sample. In the round 29 (2020) survey, 6,535 civilian and military respondents out of the 9,964 eligible were interviewed, for an overall retention rate of 65.6 percent. Retention rates for each survey are shown in Table 1. This table also shows which interviews were conducted with paper-and-pencil interviewing (PAPI) and which were executed with computer-assisted personal interviewing (CAPI).

The number of respondents can also be expressed as a percentage of the number of base year respondents not known to be deceased. This is referred to as the response rate and is reported in Table 2 for each survey round. As of 2020, 1,185 main respondents had been reported as deceased. The response rate for those believed to be alive is 74.4 percent.

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Table 1. Sample Sizes & Retention Rates by Sample Type: NLSY79
    Cross-Sectional 
Sample		 Supplemental Sample Military Sample Total Sample
Year Type & Mode of Interview ("Personal" mode can refer to either in person and by telephone) Total Retention Rate 1 Total Retention Rate 1 Total Retention Rate 1 Total Retention Rate 1
1979 Personal/PAPI 6111 - 5295 - 1280 - 12686 -
1980 Personal/PAPI 5873 96.1 5075 95.9 1193 93.2 12141 95.7
1981 Personal/PAPI 5892 96.4 5108 96.5 1195 93.4 12195 96.1
1982 Personal/PAPI 5876 96.2 5036 95.1 1211 94.6 12123 95.6
1983 Personal/PAPI 5902 96.6 5093 96.2 1226 95.8 12221 96.3
1984 Personal/PAPI 5814 95.1 5040 95.2 1215 94.9 12069 95.1
1985 Personal/PAPI 5751 94.1 4957 93.6 1862 92.5 108943 93.9
1986 Personal/PAPI 5633 92.2 4839 91.4 183 91.1 10655 91.8
1987 Telephone only/PAPI 5538 90.6 4768 90.1 179 89.1 10485 90.3
1988 Personal/PAPI 5513 90.2 4777 90.2 175 87.1 10465 90.2
1989 Personal/PAPI/CAPI 5571 91.2 4853 91.7 181 90.0 10605 91.4
1990 Personal/PAPI/CAPI 5498 90.0 4755 89.8 183 91.0 10436 89.9
1991 Personal/PAPI 5556 90.9 32814 89.9 181 90.0 90185 90.5
1992 Personal/PAPI 5553 90.9 3280 89.8 183 91.0 9016 90.5
1993 Personal/CAPI 5537 90.6 3293 90.2 181 90.0 9011 90.4
1994 Personal/CAPI 5457 89.3 3256 89.2 178 88.6 8891 89.2
1996 Personal/CAPI 5290 86.6 3171 86.8 175 87.1 8636 86.7
1998 Personal/CAPI 5159 84.4 3065 83.9 175 87.1 8399 84.3
2000 Personal/CAPI 4949 81.0 2921 80.0 163 81.1 8033 80.6
2002 Personal/CAPI 4775 78.1 2792 76.5 157 78.1 7724 77.5
2004 Personal/CAPI 4686 76.7 2818 77.2 157 78.1 7661 76.9
2006 Personal/CAPI 4629 75.7 2862 78.4 162 80.6 7653 76.8
2008 Personal/CAPI 4688 76.7 2908 79.6 161 80.1 7757 77.8
2010 Personal/CAPI  4602 75.3 2808 76.9 155 77.1 7565 75.9
2012 Personal/CAPI 4422 72.4 2731 74.8 147 73.1 7300 73.3
2014 Personal/CAPI 4263 69.8 2660 72.8 147 73.1 7070 71.0
2016 Personal/CAPI 4192 68.6 2581 70.7 139 69.2 6912 69.4
2018 Personal/CAPI 4147 67.9  2587   70.8  144 71.6  6878  69.0 
2020 Personal/CAPI 3942 64.5 2458 67.3 135 67.2 6535 65.6
 
1  Retention rate is defined as the percentage of base year respondents within each sample type remaining eligible who were interviewed in a given survey year. Included in the eligible sample are deceased and difficult to field respondents whom NORC does not attempt to contact.
2  A total of 201 military respondents were retained from the original sample of 1,280.
3  The total number of civilian and military respondents in the NLSY79 at the beginning of the 1985 survey was 11,607.
4  Economically disadvantaged, nonblack/non-Hispanic female and male members of the supplemental subsample are not eligible for interview as of the 1991 survey year. Remaining eligible for interview in post-1990 surveys are 3,652 black and Hispanic or Latino respondents of the supplemental sample, of whom 3,281 were interviewed in 1991.
5  The total number of civilian and military respondents in the NLSY79 at the beginning of the 1991 survey was 9,964.

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Table 2. Response Rates (Excluding Deceased Sample Members) by Sample Type: NLSY79
  Cross-Sectional Sample Supplemental Sample Military Sample Total Sample
Year # Response Total Deceased Rate # Response Total Deceased Rate # Response Total Deceased Rate # Response Total Deceased Rate
1979 6,111 0 - 5,295 0 - 1,280 0 - 12,686 0 -
1980 5,873 4 96.2 5,075 5 95.9 1,193 0 93.2 12,141 9 95.8
1981 5,892 15 96.7 5,108 14 96.7 1,195 0 93.4 12,195 29 96.3
1982 5,876 24 96.5 5,036 19 95.5 1,211 1 94.7 12,123 44 95.9
1983 5,902 27 97.0 5,093 26 96.7 1,226 4 96.1 12,221 57 96.8
1984 5,814 30 95.6 5,040 33 95.8 1,215 4 95.2 12,069 67 95.6
1985 5,751 36 94.7 4,957 43 94.4 1861 0 92.5 10,8941 79 94.5
1986 5,633 43 92.8 4,839 51 92.3 183 1 91.5 10,655 95 92.6
1987 5,538 51 91.4 4,768 56 91.0 179 3 90.4 10,485 110 91.2
1988 5,513 56 91.0 4,777 68 91.4 175 3 88.4 10,465 127 91.2
1989 5,571 60 92.1 4,853 78 93.0 181 3 91.4 10,605 141 92.5
1990 5,498 67 91.0 4,755 82 91.2 183 3 92.4 10,436 152 91.1
1991 5,556 75 92.0 3,2812 65 91.5 181 4 91.9 9,0182 144 91.9
1992 5,553 81 92.1 3,280 71 91.6 182 4 92.4 9,015 156 91.9
1993 5,537 90 92.0 3,293 83 92.3 181 4 91.9 9,011 177 92.1
1994 5,457 104 90.8 3,256 96 91.6 178 4 90.4 8,891 204 91.1
1996 5,290 129 88.4 3,171 109 89.5 175 5 89.3 8,636 243 88.8
1998 5,159 152 86.6 3,065 118 86.7 175 5 89.3 8,399 275 86.7
2000 4,949 170 83.3 2,921 136 83.1 163 7 84.0 8,033 313 83.2
2002 4,775 188 80.6 2,792 151 79.7 157 7 80.9 7,724 346 80.3
2004 4,686 221 79.6 2,818 171 81.0 157 7 80.9 7,661 399 80.1
2006 4,629 252 79.0 2862 197 82.8 162 7 83.5 7653 456 80.5
2008 4688 274 80.3 2908 222 84.8 161 7 83.0 7757 503 82.0
2010 4602  309 79.3 2808 255 82.7 155 9  80.7  7565 573  80.6
2012 4422  384 77.2 2731 292 81.3 147 13 78.2 7300 689  78.7
2014 4263  444 75.2 2660 331 80.1 147 15 79.0 7070 790 77.1
2016 4192 512 74.9 2581 385 79.0 139 18 76.0 6912 915 76.4
2018 4147 576 74.9 2587 435 80.4 144 22 80.4 6878 1033 77.0
2020 3942 659 72.3 2458 502 78.0 135 24 76.3 6535 1185 74.4
 
Note: Response rate is defined as the percentage of base-year respondents remaining eligible and not known to be deceased who were interviewed in a given survey year.
1A total of 201 military respondents were retained from the original sample of 1,280; 186 of the 201 participated in the 1985 interview. The total number of NLSY79 civilian and military respondents eligible for interview (including deceased respondents) beginning in 1985 was 11,607.
2 The 1,643 economically disadvantaged nonblack/non-Hispanic male and female members of the supplemental subsample were not eligible for interview as of the 1991 survey year. The total number of NLSY79 civilian and military respondents eligible for interview (including deceased respondents) beginning in 1991 was 9,964.

Reasons for Noninterview

A 'Reason for Noninterview' variable is constructed for each survey year (excluding 1979) in the NLSY79 and provides an explanation of why an interview could not be conducted or completed with a respondent. The cause of noninterview is assigned by the NORC interviewer to each respondent designated as a member of the eligible sample for a given survey year. Typical coding categories have included reasons such as an interview being refused by the respondent or by the respondent's parent, the respondent or family unit not being located, or the respondent being reported as deceased.

Beginning in the 1980s, two administrative categories were added. One reflected a decision by NORC not to attempt to interview certain sample members who were determined to be extremely difficult to interview. The second category indicates that, due to funding cutbacks, interviews would not be attempted with certain members of one or more of the NLSY79 subsamples. Thus, beginning in 1985, interviews ceased for 1,079 respondent members of the military subsample; each was permanently assigned a reason for noninterview of "military sample dropped." A second group of respondents, those belonging to the supplemental economically disadvantaged, nonblack/non-Hispanic sample, was similarly dropped from interviewing beginning with the 1991 survey. The target universe for each survey year--that is, the respondents whom NORC attempts to interview--thus includes all respondents interviewed in the initial survey year exclusive of those who were:

  1. reported deceased at an earlier interview
  2. dropped from the sample
  3. judged to be extremely difficult to interview

Important informationabout noninterview

Reasons for noninterview may change for a given respondent between noninterview years, even if those years are contiguous. Some codes, such as "parent refusal/break off," have become virtually obsolete over time with the aging of the cohort. Other codes should be considered relatively permanent, such as those applied to the reported death of a respondent. (Users should be aware that false reports of death have been used to avoid being interviewed. NORC attempts to verify these reports by obtaining death certificate information or newspaper obituaries.)

The coding of deceased members of the two subsamples dropped from interviewing in 1985 and 1991 has not been handled consistently. Those respondents of the military sample reported deceased during the 1980-84 surveys, that is, those with a code of "65 - Deceased" on a 'Reason for Noninterview' variable, have been recoded, beginning in 1985, to "68 - Military Sample Dropped"; this recode occurred for four cases. Thus, the count of 1,079 reflects all members of the military subsample, both living and deceased, who were dropped from interviewing; however, this means that the cumulative count of total deceased respondents on any post-1984 'Reason for Noninterview' will be understated.

The 22 members of the supplemental economically disadvantaged, nonblack/non-Hispanic sample who had died prior to the dropping of the sample in 1991 were not similarly reclassified as dropped. The count of 1,621 for the economically disadvantaged, nonblack/non-Hispanic sample in the 1991 'Reason for Noninterview' variable reflects only the living members of the total 1,643 who were dropped; the 22 deceased members of the supplemental economically disadvantaged, nonblack/non-Hispanic subsample remain coded as deceased.

Table 3 presents the number of respondents not interviewed across survey years by sample type.

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Table 3. Reasons for Noninterview by Sample Type: NLSY79 1980-2020
Key: C = Cross-sectional, S = Supplemental, M = Military
Survey
Year		 Total Not
Interviewed		 Reason for Noninterview
Refusal Can't Locate Deceased Other Difficult Cases Dropped1
    C S M C S M C S M C S M C S M C S M C S M
1980 238 220 87 153 91 9 60 101 56 4 5 0 21 23 22 0 0 0 0 0 0
1981 219 187 85 133 71 16 30 64 20 15 14 0 41 38 49 0 0 0 0 0 0
1982 235 259 69 86 73 18 56 123 30 24 19 1 7 25 18 62 19 2 0 0 0
1983 209 202 54 103 94 23 43 63 18 27 26 4 15 14 8 21 5 1 0 0 0
1984 297 255 65 204 138 32 54 73 24 30 33 4 9 11 5 0 0 0 0 0 0
1985 360 338 1094 180 146 5 51 94 7 36 43 0 10 14 2 83 41 1 0 0 1079
1986 478 456 1097 284 230 10 78 115 7 43 51 1 14 22 0 59 38 0 0 0 1079
1987 573 527 1101 286 217 5 118 165 10 51 56 3 28 39 1 90 50 3 0 0 1079
1988 598 518 1105 335 248 4 107 128 13 56 68 3 43 36 4 57 38 2 0 0 1079
1989 540 442 1099 316 202 7 90 93 5 60 78 3 19 25 2 55 44 3 0 0 1079
1990 613 540 1097 385 269 8 101 139 6 67 82 3 23 28 1 37 22 0 0 0 1079
1991 555 1992 1099 316 182 9 97 99 6 75 65 4 8 13 1 59 12 0 0 1621 1079
1992 558 1993 1097 323 196 7 82 70 6 81 71 4 11 16 1 61 19 0 0 1621 1079
1993 574 1980 1099 338 191 11 57 62 3 90 83 4 12 10 1 77 13 1 0 1621 1079
1994 654 2017 1102 398 196 9 78 59 9 104 96 4 11 14 0 63 31 1 0 1621 1079
1996 820 2102 1105 486 216 6 86 87 11 128 109 5 22 23 1 98 46 3 0 1621 1079
1998 952 2208 1105 490 233 8 117 146 9 152 118 5 74 59 1 119 31 3 0 1621 1079
2000 1162 2352 1117 689 333 15 162 180 11 170 136 7 58 61 4 83 21 1 0 1621 1079
2002 1336 2503 1123 684 394 14 201 195 14 188 151 7 65 66 4 198 54 51 0 1621 1079
2004 1425 2477 1123 790 328 16 240 197 15 221 171 7 119 80 3 55 58 3 0 1621 1079
2006 1482 2433 1118 969 403 20 165 138 10 252 197 7 38 19 0 58 33 2 0 1643 1079
2008 1423 2387 1119 814 311 14 177 149 10 274 222 7 103 31 7 55 31 2 0 1643 1079
2010 1509 2487 1125  795 334 22 194 162 14 309 255 9 98 42 1  113 51  0 0 1643  1079 
2012 1689  2564 1133 649 238 16 255 198 13 384 292 13 317 152 12 84 41 0 0 1643  1079 
2014 1848 2635 1133 775 328 18 346 213 16 444 331 15 111 54 3 172 66 2 0 1643 1079
2016 1919 2714 1141 722 318 20 482 295 23 512 385 18 31 19 0 172 54 1 0 1643 1079
2018  1964  2708  1136 633 281  19   496  271 13  576  435  22  22 9 0 237 69 3 0 1643  1079 
2020 2169 2837 1145 1010 487 29 185 94 9 659 502 24 80 49 3 235 62 1 0 1643 1079
 
1 Two groups of NLSY79 respondents have been dropped from interviewing: (1) 1,079 members of the 1,280 military subsample were dropped after the 1984 survey and (2) the 1,643 members of the supplemental economically disadvantaged, non-black/non-Hispanic subsample were dropped after the 1990 interview.

Sample Representativeness & Attrition

This section reviews the number of respondents by race, sex, and NLSY79 sample type who have continued to be interviewed during all surveys. It also takes a brief look at the racial composition of the cohort at the initial and latest survey points. Table 4 shows the number of respondents, excluding dropped respondents, who were interviewed at all survey points. This table exhibits the high degree of NLSY79 retention. From 1979 to 2020 the survey has been administered 29 times.

Table 4. Percentage of NLSY79 Respondents, Excluding Dropped Respondents, Who Answered Every Survey: 1979-2020
Year Percent Number   Year Percent Number
1979 100% 9964 1993 73.2% 7291
1980 96.0% 9571 1994 71.8% 7153
1981 94.3% 9395 1996 69.6% 6935
1982 92.7% 9234 1998 69.9% 6664
1983 91.6% 9125 2000 63.3% 6310
1984 89.7% 8942 2002 60.3% 6004
1985 87.5% 8721 2004 57.6% 5736
1986 85.0% 8472 2006 55.6% 5538
1987 82.3% 8203 2008 54.3% 5407
1988 79.9% 7957 2010 52.3% 5208
1989 78.5% 7819 2012 50.3% 5012
1990 76.7% 7642 2014 48.0% 4787
1991 75.5% 7521 2016 46.3% 4613
1992 74.2% 7396 2018 44.7%  4452 
        2020 42.5% 4239

Table 5 shows the distribution of the number of interviews completed by respondents, broken down by sample type. The "# who completed" column shows how many respondents completed exactly that number of surveys. These numbers refer to any surveys completed since the NLSY79 began, not necessarily consecutive surveys completed or surveys completed in particular years. The cumulative percent column shows a cumulative total percent of those completing at least a given number of surveys rather than a percentage of those completing an exact number of surveys. Readers should note the attrition suggested in Table 3 greatly overstates the amount of lost information. The NLSY79 asks detailed questions about work history, education, training, marital status, and fertility since the date of the respondent's last interview. These retrospective questions capture information lost due to missed interviews. Hence, a perfect response record is not needed for researchers to understand how the respondent's life changes over time, unless he or she leaves the survey forever.

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Table 5. Number of Interviews Respondents Completed out of 29 Surveys by Sample Type: NLSY79 1979-2020
  Total Sample Cross Sectional Sample Supplemental Sample Military Sample
# of Surveys1 # who Completed Cumul. Percent # who Completed Cumul. Percent # who Completed Cumul. Percent # who Completed Cumul. Percent
1 39  0.4 25 0.4 14 0.4 0 -
2 38  0.4 22  0.4  15  0.4  1 0. 5
3 29  0.3 19 0.3 10 0.3 0 -
4 38 0.4 17 0.3 19 0.5 2 1.0
5 48 0.5 35 0.6 12 0.3 1 0.5
6 61 0.6 36 0.6 25 0.7 0 -
7 70 0.7 50 0.8 18 0.5 2 1.0
8 65 0.7 42 0.7 22 0.6 1 0.5
9 80 0.8 49 0.8 31 0.8 0 -
10 70 0.7 47 0.8 22 0.6 1 0.5
11 71 0.7 36 0.6 35 1.0 0 -
12 79 0.8 55 0.9 22 0.6 2 1.0
13 96 0.9 62 1.0 34 0.9 0 -
14 105 1.1 69 1.1 35 1.0 1 0.5
15 108 1.1 69 1.1 37 1.0 2 1.0
16 163 1.6 101 1.7 57 1.6 5 2.5
17 161 1.6 116 1.9 42 1.2 3 1.5
18 206 2.1 134 2.2 65 1.8 7 3.5
19 205 2.1 131 2.1 70 1.9 4 2.0
20 235 2.4 147 2.4 82 2.2 6 3.0
21 227 2.3 134 2.2 87 2.4 6 3.0
22 255 2.6 147 2.4 100 2.7 8 4.0
23 310 3.1 177 2.9 122 3.3 11 5.5
24 340 3.4 196 3.2 137 3.8 7 3.5
25 416 4.2 261 4.3 150 4.1 5 2.5
26 498 5.0 267 4.4 213 5.8 18 9.0
27 625 6.3 333 5.4 275 7.5 17 8.5
28  1087  10.9 622 10.2 446 12.2 19 9.5
29 4239 42.5 2712 44.4 1455 40.0 72 35.8
Total 9964 100% 6111 100% 3652 100% 201 100%
 
Note: Universe excludes the 1,079 members of the military subsample and the 1,643 members of the economically disadvantaged, non-black/non-Hispanic oversample dropped from interviewing; it includes the remaining 9,964 eligible members.
1 Surveys completed in any year, not necessarily consecutive survey years.