st: What should I do if stata can not show the result of nbreg

[Ye SUN <sunye74stata@gmail.com>]

Dear all
My dependent variable is count number: the number of boards that a
director serves in (this kind of data seems not fit to poisson)

 I first try poisson regression and get the results and then I  try
-estat gof-  to test whether there is overdispersion problem, it is
insignificant indicating no overdispersion problem I think.
I also try -zip- and get similar results, and vuong test indicates
there is no excess zero problems I think.

I also want to try negative binomial regression,(  nbreg  and zinb ),
but stata run for quite a long time and still run without showing any
results. What does that mean? Dose it mean that nbreg is inappropriate
here?

I want to ask, if -estat gof- after -poisson- shows the insignificant
results, can I say this poisson model is OK and do not need to provide
negative binomial regression results?

Thanks for your help!

SUN Ye
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