On Sun, Dec 2, 2012 at 5:24 AM, Adel Enpaya <Adel.Enpaya@uws.ac.uk> wrote:
>
> Dear Stateliest
> I have data set of 183 observations and 36 variables include 13 dummy variables when I run Tobit regression model, No results obtain, but if if I reduce the number of variable , I can obtains result, is there any relationship between number of variables, number and observations and (degree of freedom)
>
Stata's error messages are sometimes a bit cryptic but are usually
very helpful. I suspect you have perfect prediction happening or some
other issue, such as a non-concave likelihood. That's a lot of
variables for the number of observations for this kind of model and
you probably don't have the data to run the model you want. Try
deleting each variable in turn to see if you can identify the trouble
variable.
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