Hey,

I'm trying to fit a panel regression.
I start by using:
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xtset Year country_id
I then type:
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xtreg Y X i.Year, re robust
and:
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xtreg Y X i.Year, fe robust

Everything works fine with the RE model.
When I use the FE model, however, Stata drops all the time dummies:
"note: 2004.Year omitted because of collinearity, note: 2005.Year omitted because of collinearity... note: 2020.Year omitted because of collinearity."
What might be the reason for that? How can I fix the issue?
It is important to note that I have changed many Xs and Ys.

Many thanks,
Dan