topic Re: Handling longitudinal data in Statistical Procedures

Handling longitudinal data

Neil_C — Thu, 09 Jan 2014 21:27:14 GMT

I have student data for the last 10 years – all of them
belong to a particular cohort (depending on the session or the year they
started in the University). I am interested in various longitudinal analyses on
SAS- for example, I need to see the change in courses they took (defined by
variable called subject) over time for each cohort, or for e.g. whether they graduated
in 4 years or alternatively where they dropped off during their stay in the
University.

For each student I have their individual details including unique
id, session data, year they started, program they are in, subject etc. I am
pondering over the best way to tackle this.

Any help appreciated. Please let me know if you need any
other additional info.

Re: Handling longitudinal data

ets_kps — Wed, 15 Jan 2014 21:51:28 GMT

Hello,

Thank you for your question. It actually seems that your problem is more closely related to reporting and processing longitudinal/panel data than it is about estimating a panel model.

There are couple of ways to do this in SAS with the most common to be using DATA step concepts or with PROC MEANS and some BY groups.

I would go a different direction and use PROC TIMEDATA to do this. since you have repeat observations on a student at different moments in time, your 'by group' would be a student ID. You would then use TIMEDATA like a datastep but instead of thinking about the PDV being a row, think about the PDV as a column of data.

If you provide some data I wouldn't mind taking a crack at solving your problem. -Ken