Dear statalist,
I'm running a loglinear model using the -glm- command (Stata 9SE,
Windows XP):
glm depvar a*b*c*d, fam(pois)
I'm specifying 4-way-interactions but unfortunately some of the
coefficients are beeing dropped because of the collinearity. I'm sure
that I did not use the same variables twice.
Assuming that my model is ok. :-) , what could be other possible reasons
for dropping coefficients?
Thank you very much for any comments!
Joan
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
