--- "Peter F. Schmidt" <[email protected]> wrote:
> thanks for the hint. that seems to the right model. i tried to use
> the ztnb but stata gives the error message that convergence could not
> be achieved. on the ucla stata page is a warning that the method
might
> be problematic with a small sample, but it is unclear what is a small
> sample. i have 180 observations. do you have any idea how to get the
> regression running?
One thing you could do is to estimate a -ztp- model with the
-vce(robust)- option.
Hope this helps,
Maarten
-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting address:
Buitenveldertselaan 3 (Metropolitan), room Z434
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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