Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Interpretation of Interaction terms in log-lin


From   [email protected] (Brendan Halpin)
To   [email protected]
Subject   Re: st: Interpretation of Interaction terms in log-lin
Date   Tue, 22 May 2012 11:41:52 +0100

On Tue, May 22 2012, Lukas Borkowski wrote:

> my simplified model can be written as y = ß0 + ß1x1 + ß2x2 + ß3x1_x2
> with the last expression being an interaction term.
>
> However, the dependent variable is in logs and the explanatory variables
> are not. I now wonder whether I have to add ß2 and ß3 before putting
> them into the e-function or to exponantiate each coeffecient seperately
> and then do the addition?

Not quite an answer but if you have a logged dependent variable this
piece by William Gould is very helpful:

http://blog.stata.com/tag/poisson-regression/

Towards an answer: I'd interpret the effect of the interaction the same
as in any other linear model, and deal with the relationship between the
(linear) predicted value and your original variable in a second step.

Brendan
-- 
Brendan Halpin,   Department of Sociology,   University of Limerick,   Ireland
Tel: w +353-61-213147  f +353-61-202569  h +353-61-338562;  Room F1-009 x 3147
mailto:[email protected]    ULSociology on Facebook: http://on.fb.me/fjIK9t
http://teaching.sociology.ul.ie/bhalpin/wordpress         twitter:@ULSociology

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/


© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index