Re: st: stepwise et al

["b.qureishi" <b.qureishi@ucl.ac.uk>]

Thanks for the prompt response Phil.
I was using qregs to control against outliers. Subsequently, due to the 
lack of
observations I was not getting any t-values. Ive manually adjusted my outliers
and am now using standard regs as oppose to the former.

Kind Regards,
Bilal
Quoting Phil Schumm <pschumm@uchicago.edu>:


> On Aug 27, 2007, at 10:52 AM, b.qureishi wrote:
> > Instead a T statistic, I would get "." Does anyone know why this is  
> > happening?
>
> Presumably because Stata is unable to calculate the corresponding  
> standard error(s) in this case.  This is often the result of some  
> collinearity among your covariates, or some lack of variation in your 
>  outcome, or a mixture of both.  Also, pay attention to your  
> estimation sample (i.e., the set of observations being used to  
> estimate the model); often this gets reduced to a subset of the  
> entire sample for some reason (e.g., missing data), and that's what  
> leads to the problem.
>
>
> -- Phil
>
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