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

 From Ye SUN To statalist@hsphsun2.harvard.edu Subject Re: st: What should I do if stata can not show the result of nbreg Date Sun, 8 Jan 2012 21:25:56 +0800

```Thanks for reminding.
I use stata 11. My dependent variable is the number of boards that a
director serves in.(Nboards) My test independent variable is the
gender of the director, dummy variable (FD).
So I want to run the following regression:  nbreg  Nboards  FD  (other
control variables)

I input the above command in stata, but it runs for hours and keeps showing

Iteration 50:  log likelihood = -58271.444  (backed up)
numerical derivatives are approximate
flat or discontinuous region encountered
Iteration 51:  log likelihood = -58271.444  (backed up)
numerical derivatives are approximate
flat or discontinuous region encountered
Iteration 52:  log likelihood = -58271.444  (backed up)
numerical derivatives are approximate
flat or discontinuous region encountered
Iteration 53:  log likelihood = -58271.444  (backed up)

I want to know how to solve this problem if it still can not show the
final results.

I also want to know what is the difference between the command -nbreg-
and -nbinreg-, please? It seems both of them are used for negative
binomial regression.

Thanks a lot

SUN Ye

On Sun, Jan 8, 2012 at 4:36 PM, Muhammad Anees <anees@aneconomist.com> wrote:
> A little picture of what you really did with -nbreg- will help us
> understand your problem and also indicate what version of Stata is
> used.
>
> On Sun, Jan 8, 2012 at 1:24 PM, Ye SUN <sunye74stata@gmail.com> wrote:
>> 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?
>>
>>
>> SUN Ye
>> *
>> *   For searches and help try:
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>> *   http://www.ats.ucla.edu/stat/stata/
>
>
>
> --
>
> Best
> ---------------------------
> Assistant Professor/Programme Coordinator
> COMSATS Institute of Information Technology
> Attock 43600, Pakistan
> http://www.aneconomist.com
>
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```