On Fri, May 30, 2008 at 4:42 PM, Michael McCulloch <[email protected]> wrote:
> Hello,
> I'm creating survival data, and puzzled by two observations here, which
> probably reflect my elementary knowledge of the subject. Perhaps someone can
> offer some helpful advice.
>
> 2. Why the confounder variable "w" is dropped due to collinearity?
Because w only takes two values depending on the value of "a"
. disp (1/(1+exp(-(-1.74))))
.14931293
. disp (1/(1+exp(-(-1.74+1))))
.32300414
Scott
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