- The Recall Experiment
- Effects on NLSY79 Data
- Effects on Auxiliary Data Files and Variables in NLSY79
The Recall Experiment
Beginning with the 1996 survey, the NLSY79 became a biennial survey. In anticipation of reverting to a two-year interview period, an experiment dubbed the "Recall Experiment" was conducted in 1994 on a portion of the eligible sample. A sub-sample was drawn from the members of the original 12686 sample still eligible for interview in 1994, who were also interviewed in 1992 and 1993. This sub-sample was treated as if their 1993 interview never took place; their date of last interview was established as the 1992 interview date. The information that drove the 1994 interview was that gathered in the 1992 interview. The affected respondents were periodically reminded where applicable, that the reference date for their interview was not the 1993 interview date, but the 1992 interview date.
The result for the 854 "recall respondents" interviewed in 1994 is that retrospective information, pertaining mainly to the period since the last interview, was essentially re-reported for the period between the 1992 and 1993 interviews, in addition to the new information for the 1993-94 survey period. The re-reported information for the 1992-93 interview period can be compared to that previously reported during the 1993 interview for possible discrepancies.
The goal of this experiment was to gain a better sense of the possible consequences for respondent recall, of a biennial instead of annual survey administration, for accuracy and consistency of data and overall respondent burden of participating in the survey. Certain segments of NLSY79 surveys in specific years have previously collected retrospectives over a two-year period or longer. For example, the more detailed two-year fertility history sponsored by The National Institute for Child Health and Development (NICHD) has been administered in selected survey years. However, except in the case of a respondent who actually skips one or more interviews, retrospectives in most segments of the questionnaire for a given year, have required that a respondent only recall events and circumstances over the period of roughly a year.
Effects on NLSY79 Data
Because the information for the 1992-1993 interview period was reported twice -- both during the 1993 and 1994 interviews -- users may encounter some degree of difference and inconsistency in that data gathered in 1993 and 1994. Data pertaining to past calendar year, such as spouse's labor force activity or respondent's income and assets, is not affected by the experiment. Retrospectives for which data between the 1992 and 1993 interview period would have been reported both in the 1993 and 1994 interviews is listed below.
Marital History
- Retrospective/event history of changes in marital status since date of last interview
Regular Schooling
- Two-year retrospective of specific months of enrollment (if any) in regular school for the 1993 calendar year only
- Retrospective/event history of college attendance since date of last interview
Military
- Retrospective/event history of military enlistment and separation dates since date of last interview
On Jobs/Employer Supplements
- Retrospective/event history of employment with specific employers, and periods not working for specific employers (gaps within jobs), since date of last interview
Gaps
- Retrospective/event history of periods of non-employment (gaps between employers), since date of last interview
Training
- Retrospective/event history of (continued) participation since the last interview, in training programs either reported at the date of last interview or enrolled in since the date of last interview
Health
- Retrospective/event history of most recent and most severe work-related injuries (if any), since date of last interview
Income and Assets
- Retrospective/event history of program recipiency (respondent/spouse unemployment compensation, AFDC, government food stamps, SSI/other welfare) since either December 1992, if receipt reported during that month, or January 1993 for those not reporting receipt in December 1992
The Fertility History section is a special case with respect to the Recall Experiment. Between the 1986 and 1992 interview years, in which paper-and-pencil interviewing (PAPI) was used, information on biological children was collected in each odd-numbered year on any biological children born since the date of last interview. However, even-numbered years contained an expanded fertility history section, sponsored by NICHD. This expanded history included a re-reporting of biological children born since the date of the last NICHD interview (even-numbered year). Newly reported children were handwritten onto the records when paper-and-pencil instruments were being used. This allowed interviewers to easily identify children about whom certain series of questions should be asked. The fertility data therefore, has for years contained a limited version of the 1994 Recall Experiment, specific to biological children. Other segments of the fertility history (pregnancy information for female respondents and visitation habits of biological children with non-residential parents) were collected exclusively as two-year retrospectives in even-numbered years. With the advent of CAPI interviewing, it was decided that re-reporting of biological children in NICHD years was no longer necessary. Interviewers no longer needed to rely on visual identification of children reported since the last NICHD interview, because these children could be mechanically flagged. Therefore, in 1994, respondents not belonging to the Recall Experiment sample were for the first time since 1986, only required to report new children born since the date of last interview, instead of the last NICHD interview (two years ago in most cases). However, Recall Experiment respondents were asked to update their biological child records since the last NICHD interview year (1992), as was the norm in even-numbered years since 1986. This will continue to be the case for all respondents with the biennial administration, which began in 1996. However, the elimination of the odd-year survey also means the continued elimination of re-reporting of children born since the last NICHD interview.
Effects on Auxiliary Data Files and Variables in NLSY79
The potential seam effects introduced by the Recall Experiment are particularly relevant for the work history data file and the creation of the key variable, Total Net Family Income. In each case, a different procedure was used to eliminate possible discrepancies in information reported both during the 1993 and 1994 interviews.
WORK HISTORY 1979-1994 DATA FILE
The 1979-93 release of the work history data file already incorporated information covering the period between the 1992-93 interviews in each respondent's longitudinal labor force history. The possible disruptions that might occur to the longitudinal record, if inconsistent data were introduced into the formulas for a single time frame, were unpredictable and potentially serious. It was determined that information covering the period between the 1992 and 1993 interview, reported by the recall respondents in the 1994 interview, would be eliminated for the purposes of creating the 1979-94 work history file. The following basic decision rules were applied:
- Data pertaining to employers, gaps in employment and/or periods of military service for which the start and stop dates fell completely prior to the 1993 interview date for recall respondents were completely eliminated for the purposes of creating the 1979-94 work history data file. These should have been reported during the original 1993 interview;
- Data pertaining to employers, gaps in employment and/or periods military service for which the start and stop dates fell completely within the period between the 1993 and 1994 interview were retained in their entirety. These constitute new information and would not have been reported during the 1993 interview;
- Data pertaining to employers, gaps in employment and/or periods military service for which the start and stop dates fell partially prior and partially after the 1993 interview date, was truncated where necessary at the 1993 interview date (e.g. start dates of these periods of employment/non-employment were set to the 1993 interview date).
Users should note that, with respect to gaps in employment, the NLSY79 does not establish specific weeks when a respondent might be looking for work or laid off (making him/her unemployed as opposed to out of the labor force or OLF). Respondents report only a total number of weeks during each gap for each status. This made it impossible to determine which segment of the 1992-94 interview period should be assigned the unemployed code and which the OLF code for gaps which fell partially prior and partially after the 1993 interview, and in which the respondent reported both statuses.
TOTAL NET FAMILY INCOME
For the purposes of creating Total Net Family Income, the total number of weeks/months of program recipiency in the past calendar year (1993) and the average amount received per week/month in 1993 are required. Recall respondents would have reported all 1993 recipiency in the 1994 interview, not just that occurring prior to the 1993 interview date. Therefore, 1994 data was used exclusively to compute the total 1993 recipiency figures for the recall respondents. This avoided the task of attempting to combine data from 1993 and 1994 for these respondents and deal with potential inconsistencies in reports between the two interviews.