Dear statalists,
I estimate my data with xtnbreg with -fe option and found that all
zero outcomes were automatically dropped.
Why does it drop such outcomes? Is it different from conventional fixed effects?
I would like to compare the results of OLS, FE and RE negative
binomial using hausman test.
But, since OLS and RE keep all observations with all zero outcomes, it
seems to be unreasonable to do it.
In addition, if I exclude all zero outcome, shouldn't I doubt for the bias?
Thank you in advance.
--
Yee Kyoung Kim
Department of Economics
PhD candidate, Seoul National University, Seoul, Korea
(Phone) 016-595-6148
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