I have a second question for you, if so. I have a time-varying
covariate labeled "sr". For all years the individual was in the
survey, I have a value for sr. But, in those years prior to them
entering the survey, I do not. This "sr" is a geographic variable,
and assuming that they lived in the same place they were living the
year they entered the survey, I can find a value for "sr" and match
it to them for that year. But, how might I do it? Here's an example
so you know the trouble I'm having:
As you can see, these three individuals all lost their virginity at
ages prior to when they entered the survey. id=261 entered the
survey when s/he was 14; id=475 when s/he was 12; id=488 when s/he
was 14. They lost their virginity, respectively, when they were 11,
11 and 10. I do not have a corresponding value for "sr" in any year
when the respondent was younger than 14. Some of these I can deal
with - for instance, for id=475, I can -replace sr=X- for certain
years, even though they were not asked questions about their sexual
behavior prior to age 14, because I have information on variables
that can let me match "sr" to the person. But what should I, can I,
do for years before 1997?
For instance, for id=261, if I wanted to know the respective "sr" for
1992-1996, I wasn't sure how to alter the data such that I can create
new rows of information for that specific person.
