Re: st: likelihood ratio test error message

[Richard Williams <Richard.A.Williams.5@nd.edu>]

At 09:11 PM 3/5/2004 -0600, Rivera, Semilla  M. wrote:
> Hello,
>
> I am attempting to run a lrtest in STATA and get the following error 
> message.  What can I do?
>
> Thank you.
> Semilla Rivera
>
> . lrtest, using (1)
>
> observations differ: 2098 vs. 2216
> r(498);
I think it probably means that the samples used for your 2 models are not 
the same.  Perhaps adding some variables caused some cases to drop out? If 
so, a possible solution might be something like

logit y x1 x2 x3 x4
estimates store model1
logit y x1 x2 if e(sample)
estimates store model2

That is, run the model with the most missing cases first, and then restrict 
the subsequent models to those cases.


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Richard Williams, Notre Dame Dept of Sociology
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