Hello,
I would like to perform Hausman's test to compare two-way fixed
effects versus two-way random effects model (that is, I have both
country and year specific effects). I estimate the models using
xtmixed but I am not sure what the correct syntax for Hausman's test
should be or whether this test can be applied to two-way models at
all.
So far, I have typed
xtmixed depvar indepvar countrydummies yeardummies
est store fixed
xtmixed depvar indepvar || _all: R.country || _all: R.year
hausman fixed
The test is perfomed and I get the chi2 value. But then I also get
"(V_b-V_B is not positive definite)."
I would appreciate any help with the correct syntax for the two-way
model or for any alterantive ways to test fixed versus random effects
in a two-way model.
Thank you very much in advance.
Kate
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