Dear statalist users:
The independence of irrelevant alternatives assumpition test using "mlogtest, hausman base" command has an error after running the multinominal logit regression.
My dependent variable is a categorical variables with 5 outcomes. My independent variables are dummy variables and continuous variables. For example, education which is one of the independent variables is has 5 levels- illiteracy, primary school, junior high school, high school, university. I choose illiteracy as the reference group and set 4 dummy variables Edu1, Edu2, Edu3, Edu4.
I run the regression by "
Code:
 mlogit Y X1  X2 Edu1 Edu2 Edu3 Edu4 ...
". I use "
Code:
mlogtest, hausman base
" to test the independence of irrelevant alternatives assumpition. However, it shows the error as follow:
Code:
mlogtest, hausman base
Problem determining number of categories.
**** Hausman tests of IIA assumption
 Ho: Odds(Outcome-J vs Outcome-K) are independent of other alternatives.
You used the old syntax of hausman. Click here to learn about the new syntax.
(storing estimation results as _HAUSMAN)
factor variables and time-series operators not allowed
r(101);
Why is this happening? How to solve it? I am looking forward to your help. Thank you very much.