Hi to all Stata experts,
I am currently new to Stata and I am trying to make a differences-in-differences analysis using electoral panel data within two years (1997 and 2000) where the treatment takes place in 2000 over a set of municipalities. I used the following code:
My idea is having fixed effects by municipality. Nevertheless, Stata tells me that my treatment variable is omitted because of collinearity and that is problematic since I need that variable to assure the validity of the interaction and finally of my treatment. There is something I am missing in the code or in my identification strategy? I have the same problem even dropping the set of controls.
Thanks in advance,
Iván Higuera
I am currently new to Stata and I am trying to make a differences-in-differences analysis using electoral panel data within two years (1997 and 2000) where the treatment takes place in 2000 over a set of municipalities. I used the following code:
Code:
xtreg id year xtreg yvar treatment year=2000 treatment*year [a set of controls], fe
Thanks in advance,
Iván Higuera
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