Re: st: interaction effects vs. interaction coefficients using contrast?

[Maarten Buis <maartenlbuis@gmail.com>]

On Mon, Feb 6, 2012 at 4:29 PM, Colleen Nugent wrote:
> Following the example you gave in the Stata tip, if I wanted to know whether black women with a college degree had significantly different odds than white women with a college degree, the best way to do it is to use margins and then lincom to make this comparison?

In that case I would just re-estimate the model with a variable
noncoll (a indicator variable for non-college degree) instead of
collgrad. Than the reported number by -logit- with the -or- option of
-black- will be the ratio of the odds when both black and white women
have a college degree. If this ratio is 1 than the odds are equal, and
this is already the null hypothesis of the test reported in the
regression output, so than you are done.

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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