Re: st: Interpretation of interaction term in nonlinear models

[Suryadipta Roy <sroy2138@gmail.com>]

Maarten,
This is very helpful, thank you very much! For some reason, I thought
that the z_phd variable in your example is a categorical variable as
well when I had previously read the thread. I guess that I would need
to standardize my continuous variable for a similar interpretation.

Sincerely,
Suryadipta.

On Thu, May 30, 2013 at 7:19 AM, Suryadipta Roy <sroy2138@gmail.com> wrote:
> Dear Statalisters,
>
> I am studying the effect of an interaction between a categorical
> variable (0/1) and a continuous variable (0-6) on the dependent
> variable in a nonlinear model (using -xtpoisson-). The value of the
> coefficient using the -irr- option is 0.90, while the size of the
> interaction term in the probability metric form is, of course, -0.11
> (exp(-0.11) = 0.90). My basic question is, if it might be possible to
> have a one-sentence interpretation of the value of the coefficient in
> the multiplicative form (0.90), e.g. something in the lines of "the
> effect of the categorical variable increases by a factor of 0.9 (i.e.
> a 10% reduction of the dependent variable) due to an 1% increase in
> the continuous variable"? Any suggestion in this regard will be highly
> appreciated.
>
> Sincerely,
> Suryadipta Roy.
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