Re: [Gretl-users] fixed effects panel estimation
Am 17.07.2009 21:12, Iveta Paterova schrieb:
Hello everybody,
it may sound silly, but I simply cannot understand why when calculating
fixed effects panel estimation, some variables are "omitted due to the
collinearity" and the constant remains. Should not also constant disappear
from the estimation - as it bears the fixed effects???
I am calculating log-gravity models and the important variables are
omitted. What do I do wrong?
How can I get know the coefficient of omitted variables? IT IS IMPROTANT
FOR MY ESTIMATION?
Thank you for your help.
Iveta,
it sounds as if the omitted variables only vary in the cross-section
dimension, not over time. That you collinearity then is a general
problem of a fixed-effects specification, not of gretl's implementation.
You might try a random-effects model, but if that happens to be rejected
as biased, then you're out of luck. You would then need to think of a
different approach to get your coefficient estimates, probably by
checking out what textbooks like Wooldridge suggest.
good luck anyway,
sven