--- Lloyd Dumont <[email protected]> wrote:
> Thanks, Maarten. After a lot of thinking about this
> and looking over which parts of the code generated
> which parts of the graph and trying to recall how
> marginal changes are computed with a logit, I think I
> get your example. But, I'm still not sure how to
> translate that back to a poisson or negative binomial
> context---and if the panel nature of the data make it
> even more complex.
I see three scenarios:
1) You are content of interpreting in terms changes in
ln(rate) instead of rate. In this scenario there is
no need to do anything special.
2) You want to know how the effect of x1 on the rate
changes when x2 changes and you don't care whether
that change in effect is due to the interaction
term or due to change in effect that would occur
anyhow in a nonlinear model. You can use the
method proposed by Norton and collegues.
3) You want to know how much the interaction effect
adds on top of changes that would occur anyhow in
a non-linear model. Now I do not know the answer.
I guess that scenario 2 is by far the most common.
-- Maarten
-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting address:
Buitenveldertselaan 3 (Metropolitan), room Z434
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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