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National Longitudinal Survey of Youth 1979 Child and Young Adult (NLSCYA)

Retention

This section provides sample sizes for the number of times younger children and young adults of different ages have been interviewed over the life course of the survey. Given that the child interviewing process began with the 1986 interview round and continued on a biennial basis through 2014 for the Child Supplement and 2016 for the Mother Supplement, the maximum number of child interviews a respondent could have is eight, since children age into the Young Adult survey the survey round in which they turn 15 or older (12 or older since 2016) and the Young Adult interviews began in 1994. Clearly, the content varies considerably between the Child and Young Adult interviews, partly because in most rounds only younger children were assessed, and partly because many of the questions are life-cycle specific. Many questions that might be relevant for an eight- or a fourteen-year old might not be appropriate for an older adolescent, much less someone in their twenties, thirties, or forties. Additionally, there have been some changes in questions and question wording over time, so researchers who are using these data in a longitudinal manner need to carefully review the content of the questions they are using.

The Child and Young Adult surveys are characterized by inherently different question structures, modes of data collection, and indeed potentially different research agendas. It is therefore useful to present separately the sample sizes for younger and older children, even though the ultimate research agenda in many instances may join these two sample types.

Number of Child interviews

Table 1 presents the number of child interviews ever completed by the NLSY79 children as of the most recent survey round. This table references age at the end of the survey year (December 31) rather than the survey date because the age determination for inclusion as a young adult rather than a younger child was the age as of the end of the calendar year. This method of computing age avoids a need to split the fourteen-year old age group between a younger child and a young adult component. Whether one uses a survey date or end-of-year age typically has little impact on the magnitude of age-specific sample sizes. Most estimates of sample size for younger children in this users guide use child age as of the survey date. This is the reason why sample sizes by age presented across tables may not always be identical.

Table 1 indicates the total number of child interviews reported for each NLSY79 child who has ever been interviewed, regardless of current age. For this table, a child is defined as interviewed if the sampling weight (CSAMWTyyyy or CSAMWT_REVyyyy) is greater than zero for a given survey year. The greatest number of possible child interviews would be eight biennial interviews. Only 727 of the respondents at the end of 2020 fall into that category. However, Table 1 shows much larger numbers of children in all the other interview frequency categories. Children who fall into the older age categories as of the current round, but who have completed only a small number of interviews (e.g., 11 year olds with only one or two interview points), have missed some interviews. For example, an 11 year old could potentially have six completed interviews. The implications of repeat interviewing for these younger children are expanded on in the documentation on the child assessment data, where the extent of interview repetition is connected with the specific cognitive and socio-emotional assessments that the children complete at various ages.

Table 1. NLSY79 Children: Number of Child interviews by age as of December 31st, 2020
Age of Child Number of Interviews
1 2 3 4 5 6 7 8 Row Total
0-11 1 2 4 1 0 0 0 0 8
12 0 1 0 0 2 0 0 0 3
13 0 0 0 0 4 0 0 0 4
14 0 0 1 0 9 0 0 0 10
15 0 0 0 0 0 15 0 0 15
16 0 0 1 1 1 11 9 0 23
17 1 0 1 0 1 6 23 0 32
18 1 2 1 3 4 21 13 0 45
19 2 3 4 3 4 13 51 0 80
20 5 3 4 4 7 5 24 46 98
21 1 5 4 5 7 16 88 0 126
22 7 4 5 4 5 14 65 48 152
23 5 6 11 13 13 28 132 0 208
24 9 3 9 13 14 17 86 70 221
25 8 15 10 14 16 36 137 0 236
26 9 5 16 15 16 35 102 90 288
27 12 16 16 16 19 55 199 0 333
28 10 17 20 16 15 46 150 115 389
29 11 11 18 15 33 94 223 0 405
30 17 6 17 24 33 53 152 135 437
31 15 16 14 16 43 111 306 0 521
32 80 16 16 12 34 67 147 161 533
33 100 14 25 19 51 114 273 0 596
34 91 30 16 23 41 101 234 62 598
35 28 100 16 19 41 69 380 0 653
36 27 113 13 17 35 58 363 0 626
37 24 124 26 32 83 343 0 0 632
38 21 101 17 42 61 375 0 0 617
39 32 128 23 56 352 0 0 0 591
40 17 88 27 63 319 0 0 0 514
41 23 84 48 273 0 0 0 0 428
42 17 88 39 186 0 0 0 0 330
43 17 63 38 151 0 0 0 0 269
44 14 54 27 115 0 0 0 0 210
45 12 33 20 80 0 0 0 0 145
46 5 21 11 31 0 0 0 0 68
>=47 4 17 18 11 0 0 0 0 50
Column Total 626 1189 536 1293 1263 1703 3157 727 10494

Note: Interview status is defined as sampling weight greater than zero.

Number of Young Adult interviews

Tables 2a-2c extends this interview repetition concept to the young adult component of the survey. Since the young adult interview has been ongoing only since 1994, the maximum number of young adult interviews possible by 2020 is fourteen. It should be recalled that young adults age 21 or over at the date of the 1998 interview were not interviewed in that year. This leads to a potential four-year interview gap, between 1996 and 2000, for these cases. Similarly, those who were not fielded in 2000, as part of the children aged 0 to 20 of 38% of minority oversample mothers not eligible in that round, have a four-year gap from 1998 to 2002 and will have missed either their last child round or a young adult round. From 2002 to 2008, the young adult sample includes all youth age 15 and over who were available to be interviewed. Beginning in 2010, Young Adult respondents over the age of 30 will be interviewed every four years. The interviewed sample is selected by age as of December 31 of the survey year, so that approximately half of the older young adults are eligible each round. Since 2010, young adults age 31-32, 35-36, 39-40, 43-44, etc. as of December 31 of the survey year have not been fielded. In Tables 2a-2c, while the age references the end of 2020, a particular young adult may not have been interviewed in that year. Of the 8673 young adults included in Tables 2a-2c, 5670 were fielded and 4354 were interviewed in 2020. Tables 2a-2c also shows that there are substantial numbers of young adults who have had at least nine young adult interview points and a large number who have had eight interviews as young adults since 1994. Among young adults who have completed eight or more young adult interviews, more than 77% have completed every interview for which they were eligible.

Young Adult assessment history

As can be seen in Tables 2a-2c, most of the young adults have had a number of child assessment points prior to reaching age 15 and then, depending on their current age, between one and eleven Young Adult interviews since that date. The nature of the data collection changes in fundamental ways when a child transitions to being a young adult. Prior to 2016, children under age 15 were administered (or their mother completed) a variety of assessments. For children in this age range, the mother also provided a variety of information about the child's health, education, and selected other items. Beginning with the 1988 survey, children age ten and over self-administered a set of questions about their own behaviors and attitudes in a variety of domains, including education, family and peer interaction, normative and non-normative attitudes and behaviors. In 2016, no children were directly assessed, and mothers completed Mother Supplements for children ages 0 to 13. In 2018, only a small number of child health and schooling questions were asked of the mothers.

Starting in 1994, once the children reached 15, they completed the Young Adult interview designed to address most of the major dimensions of their lives: schooling, employment, family, peer interactions and issues of sexuality, and other behaviors and attitudes that permit researchers to examine in context the experiences of these young adults in a holistic manner. Beginning in 2016, children ages 12 and up were included in the YA fielding, although the children age 12 and 13 answered significantly fewer questions than those 14 and older. A flow diagram that would cross the possible survey points, encompassing the period from 1986 to the present, would follow a child from preadolescent years, describing the child development process in some detail, parallel family and child behaviors and attitudes, and culminate in a detailed profile of later adolescent-early adult transitions to adulthood. Tables 1 and 2a-2c are designed to clarify the size of the sample that permits one to maximize the panel dimensions of the data set.

Table 2a. Age of all Young Adults as of December 31, 2020 by number of YA interviews completed
Age of YA Number of YA Interviews Row Total
1 2 3 4 5 6 7 8 9 10 11-14
12-13 Years  5 0 0 0 0 0 0 0 0 0 0 5
14-16 Years 13 13 18 0 0 0 0 0 0 0 0 44
17-18 Years 3 7 56 0 0 0 0 0 0 0 0 66
19-20 Years 18 23 113 0 0 0 0 0 0 0 0 154
21-22 Years 14 15 37 182 0 0 0 0 0 0 0 248
23-24 Years 17 25 36 60 247 0 0 0 0 0 0 385
25-26 Years 14 15 22 42 65 312 0 0 0 0 0 470
27-28 Years 14 11 24 34 44 94 427 0 0 0 0 648
29-30 Years 12 27 19 38 43 78 103 464 0 0 0 784
31-32 Years 18 26 22 33 45 67 110 585 3 0 0 909
33-34 Years 13 22 22 34 38 63 97 125 515 1 0 930
35-36 Years 24 31 26 33 47 57 109 207 443 20 0 997
37-38 Years 20 18 22 32 42 58 83 104 208 317 77 981
39-40 Years 9 24 31 27 35 53 66 125 187 307 21 885
41-42 Years 9 4 13 14 18 28 42 37 60 116 252 593
43-44 Years 9 18 16 9 13 14 25 37 61 100 67 369
45-46 Years 6 7 4 6 7 9 12 30 34 42 11 168
>46 Years 2 2 0 1 1 1 4 5 4 17 0 37
Column Total 220 288 481 545 645 834 1078 1719 1515 920 428 8673
Table 2b. Age of all Young Adults as of December 31, 2020 by number of Child interviews completed
Age of YA Number of Child Interviews Note 2b.1 Row Total
0-5 6 7 8
12-13 Years 5 0 0 0 5
14-16 Years 11 24 9 0 44
17-18 Years 6 25 35 0 66
19-20 Years 22 14 72 46 154
21-22 Years 27 25 148 48 248
23-24 Years 60 41 215 69 385
25-26 Years 82 64 234 90 470
27-28 Years 97 97 342 112 648
29-30 Years 134 141 374 135 784
31-32 Years 131 170 449 159 909
33-34 Years 161 205 503 61 930
35-36 Years 139 122 736 0 997
37-38 Years 266 715 0 0 981
39-40 Years 885 0 0 0 885
41-42 Years 593 0 0 0 593
43-44 Years 369 0 0 0 369
45-46 Years 168 0 0 0 168
>46 Years 37 0 0 0 37
Column Total 3193 1643 3117 720 8673

Note 2b.1: There are only 10 young adult respondents with no child interviews.

Table 2c. Age of all Young Adults as of December 31, 2020 by total number of YA and Child interviews completed
Age of YA Number of YA and Child Interviews Row Total
1-5 6-7 8-9 10 11 12 13 14 15 16 17-18
12-13 Years 0 5 0 0 0 0 0 0 0 0 0 5
14-16 Years 1 18 17 8 0 0 0 0 0 0 0 44
17-18 Years 2 4 29 31 0 0 0 0 0 0 0 66
19-20 Years 5 19 29 64 37 0 0 0 0 0 0 154
21-22 Years 10 9 31 28 134 36 0 0 0 0 0 248
23-24 Years 12 24 44 35 54 163 53 0 0 0 0 385
25-26 Years 15 14 43 31 40 75 191 61 0 0 0 470
27-28 Years 14 19 41 27 38 56 93 280 80 0 0 648
29-30 Years 12 16 43 39 54 49 81 131 269 90 0 784
31-32 Years 17 22 43 23 40 59 87 163 333 122 0 909
33-34 Years 11 22 40 31 44 53 80 105 169 340 35 930
35-36 Years 15 23 48 29 46 68 62 123 192 372 19 997
37-38 Years 15 34 46 38 56 63 86 106 197 278 62 981
39-40 Years 26 36 64 42 58 68 124 178 271 18 0 885
41-42 Years 16 20 51 29 31 39 67 115 191 33 1 593
43-44 Years 23 28 28 18 30 35 61 89 53 3 1 369
45-46 Years 9 16 18 13 14 23 34 32 9 0 0 168
>46  Years 4 0 6 3 3 5 10 6 0 0 0 37
Column Total 207 329 621 489 679 792 1029 1389 1764 1256 118 8673