Hi, list users,
I want to compare the zip and nbreg models. Although I know both of them
could account for the over-dispersion and the "excess-zeros", I am not
sure which mechanism, the between-subject heterogeneity or the different
process fo zero & non-zero counts, actually result into the
over-dispersion and excess-zero.
Unfortunately, the Stata FAQ said there is no test of nonnested modesl to
compare the zip and nbreg. Can anybody give me suggestions regarding
this?
Besides, how to understand and use "inflate" in the zip model?
Thanks a lot.
Ying
*
* 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/
