-- Mckenzie, Lynda wrote:
> I am analysisng ordered categorical data with oprobit and would like to
> predict out of sample values.
>
> Eg: original variable variable1 has values 1, 2 or 3
>
> Predicted variable v1, v2 and v3
>
> When I type
> Mean v1 v2 v3, over(variable1) I get a table of mean values as follows.
> How do I interpret these mean values?
>
> V1 1 0.66
> 2 0.5
> 3 0.3
The output you show can't be the result of that command. Assuming that
variable1 has three levels the output would be something like:
V1 1 0.66
2 0.50
3 0.15
V2 1 0.10
2 0.10
3 0.80
V3 1 0.24
2 0.40
3 0.05
This is interpreted as: For cases with a value of 1 on variable1 the
average predicted probability to be belong to category 1 of the explained
variable is 66%, 10% to belong to category 2, and 24% to category 3. For
cases with a value of 2 on variable 1 the average predicted probability of
belonging to category 1 of the explained variable is 50%, 10% for category
2, and 40% to category 3. and so on.
Have a look at -findit spost- for lots of tools that help with interpreting
these kinds of models and at (Long and Freese 2006).
Hope this helps,
Maarten
J. Scott Long and Jeremy Freese (2006) "Regression Models for Categorical
Dependent Variables Using Stata", Stata Press.
-----------------------------------------
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/
-----------------------------------------
*
* 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/