Thanks Austin,
One of the fixed effects was being dropped, I just had not noticed. I
appreciate the 2nd part as well. I figured there must be something
like that going on behind the scenes.
thanks again
scott
On 3/13/06, Austin Nichols <[email protected]> wrote:
> Did you check that the set of new_attid effects was complete? I.e.
> was one of the fixed effects dropped instead of pitt being dropped?
> There should be 1092 coefficients listed: _Inew_attid_2-1093. Is there
> variation in pitt across time within each panel?
>
> It is possible that collinearity can produce a dropped variable in one
> command and not another, since Stata checks for collinearity by
> checking for full rank conditions within certain tolerances, and the
> matrices checked can be different in different commands, but I would
> expect the standard errors to look very suspicious in Model 2 in that
> case, and the SE on pitt (.1575) does not look near infinity at all in
> Model 2.
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