Re: st: The sample reduces when running logistic regressions

[Maarten Buis <maartenlbuis@gmail.com>]

Sounds to me like a problem of perfect prediction. You can read more
about that here:
http://www.stata.com/support/faqs/statistics/completely-determined-in-logistic-regression/

Hope this helps,
Maarten


On Tue, Dec 17, 2013 at 6:25 PM, liliana <lilly-90@hotmail.it> wrote:
> Hello,
>
> I am running a logistic regression on different samples using multiple
> imputations:
>
> mi estimate, or post: logit Y X1 X2, vce(cluster PSU)
>
> I have run the regression for the first samples and Stata gave me back
> results where all the observations are included, except for one sample for
> which I have got 1332 observations but 1292 observations were taken by Stata
> for the regression. In addition, the categorical variable education
> (i.education which takes values 0, 1, 2, and 3) presents a problem:
> 0.education is the baseline, for 1.education and 2.education Stata gives me
> back the relative coefficient, whereas 3.education is omitted although there
> are 168 observations.
>
> Which could be the causes of these two problems?
>
> Thanks in advance.
> Lil
>
>
>
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-- 
---------------------------------
Maarten L. Buis
WZB
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Germany

http://www.maartenbuis.nl
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