Dear list members,
I am trying to test the nested interactions of 4 variables (n, a, g, and s) on the depvar drg_wgt using xi3 and glm.
Stata tells me the following:
. xi3: glm drg_wgt i.n*i.a*i.g i.a*i.g*i.s [pweight=weight] , f(gamma)
i.n _In_0-2 (naturally coded; _In_0 omitted)
i.a _Ia_0-65 (naturally coded; _Ia_45 omitted)
i.g _Ig_1-2 (naturally coded; _Ig_1 omitted)
i.s _Is_1-7 (naturally coded; _Is_4 omitted)
varlist not allowed
The code works with a 3-way term and a 2-way term, but not with 2 3-way terms. Stata should be disregarding the duplicate 2-way interactions; all 4 explanatory variables are numeric (byte); and the drg_wgt is a floating-point number. What am I missing? (What worries me is that I thought this same code had run back in January, and this now casts doubt on my memory of other events in that month.)
*
* 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/
