Dear Listers,
I've encountered this puzzling behavior of -areg-:
egen total_hh_nr = sum(hh_nr), by(keyid)
...
areg y x1 x2 total_hh_nr, absorb(keyid)
[by mistake I included total_hh_nr in the regression]. The puzzle is
that when I run the regression "total_hh_nr" doesn't drop out (as I
would expect, due to invariance within "keyid"). The standard error on
"total_hh_nr" comes out very large, of the order 10^8, so there is
something weird going on, but I cannot figure out what. Furthermore,
the coefficient on "total_hh_nr" changes at every run of the program.
So, what is going on in here?
Thanks so much,
Radu Ban
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