I am trying to run a Poisson fixed panel effects regression using
xtpoisson in Stata where my outcome variable is binary. For a majority of my units, the outcome is 0 for the entire duration of my panel. However, when I run
xtpoisson, Stata automatically omits all such units. I have the same problem when I run a
xtlogit. When I run a standard fixed effect panel with
xtreg there is no such problem.
How do I make the
xtpoisson regression work without Stata automatically omitting my units with my outcomes equal to 0. I understand that in a fixed effect regression, the regression will automatically drop all regressors which have constant values in a panel. However, I don't get why this is the case for an outcome. For instance, if my outcome is whether someone is infected
dInfected, then Stata basically drops everyone who is not infected at all for the duration for the panel. But the values of the regressors that yields a not infected outcome are still of interest to me.