Dear All,
I’m estimating the following model using stata 8.2
xi: gllamm CRH i.groups*time timesq, i(studyid) nrf(2) nip(12) eqs(inter slope) family(gamma) link(log) adapt
The model converges and works well.
Stata gave me an error when I tried to include an interaction term of time^2 with group variable as given below.
xi: gllamm CRH_ i.groups*time i.groups*timesq, i(studyid) nrf(2) nip(12) eqs(inter slope) family(gamma) link(log) adapt
Running adaptive quadrature
Iteration 0: log likelihood = -2787.6297
initial vector: duplicate entries for CRH_:_Igroups_1 found
Is there a different way of including the interaction term without explicitly creating the terms and the using them?
Thank you for any suggestions.
Leny
*
* 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/
