how do I transform waves as time measurement into years?
I have a quick question concerning the time dimension of the panel data set when using Understanding Society. Waves are defined from 1-5, but when I define some of my variables I need a calendar year, such as 2010. I found `w'_istrtdaty, which gives you the beginning year of the interview if I properly understand it. But when I write xtset pidp year I receive an error message telling me that there are repeated time values within panel.
I am afraid there are two questions I am raising here. First of all, why does the error message come up? Is it a measurement error in the `w'_istrtdaty variable? Secondly, how can I transform waves in USoc into years properly? I need an annual measure!