Re: st: which -cmp- option to use for poisson model with count data?

["Laura R." <laura.roh@googlemail.com>]

Dear all,

the distribution of the variable "number of experts" consulted is not
"zero-inflated", but rather follows a normal distribution from 0 to 5.

As there theoretically can be more than 5 experts, Nick sais, if I
understand correctly, that this would be a hint to use Poisson model,
as I would have to label the highest "category" "5 or more" in ordered
probit.

However, I have read that the events have to be independent of each
other in the Poisson model, e.g. emergency room admission (taking
David Roodman's example). This would be a reason for not using
Poisson. E.g., deciding on getting a third child probably depends on
how life is with 2 children --> ordered probit model. COnsulting
another expert can also depend on what the last one had said.

I think I will try the ordered probit model again, as this can be used
within -cmp-, while the Poisson model cannot. If the parallel
regression assumption or other assumptions for ordered probit models
turn out to be violated, I will try the Poisson model, but then I have
to come up with an idea similar to -cmp- that can be used with
Poisson. Some people in this thread gave the hint on -gllamm- and
-ssm-. I will keep that in mind and find out more about these models.

Thank you all.

LR
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