st: Closing gaps in STATA panel

[Morten Hesse <mh@crf.au.dk>]

Dear stata-listers,

I would like to request help for a problem with panels.

What I have is this:

I have a list of observations that indicate "events". These have a date 
and a subject ID.
Using "collapse" I have turned them into a panel with ID and time (years).

When the event has not occurred within a year, the observation year does 
not exist. That is, there are gaps in the panel.
I would like to add observation years for each ID with the value "0" to 
the event, when there is no event - essentially to close the gaps.
As my original dataset with events is the only relevant source of 
information about the events, the values should be zeroes.
I have tried to read about tsappend, but I could not figure out how to 
use this command for this end.
Any ideas?

Best regards
Morten
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