Re: st: xtnbreg and mfx

[Maarten buis <maartenbuis@yahoo.co.uk>]

--- On Tue, 17/8/10, Donghyun Lee wrote:
> I'm using xtnbreg for my work and I'm trying to get the
> marginal effect. However, when I type mfx after running
> the regression using xtnbreg, the coefficients are the
> same as before

If you don't specify the -predict()- option in -mfx-, then
-mfx- will use the default predict option of the preceding
estimation command. The default predict option for -xtnbreg-
is the linear predictor, so that is why you got the same
coeficients. The solution is to specify the -predict()- 
option or interpret the incidence ratios, which follow more
naturaly from count models.

Hope this helps,
Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://www.maartenbuis.nl
--------------------------


      

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