Hello,

I am trying to estimate the mixlogit using the below syntax:

mixlogit choice distance fac_type alt_dum*, rand(oop) group(case_id)

where oop, distance, and fac_type are alternative-specific variables and I would like a random coefficient for the variable oop.
In addition, I also include dummies for alternatives, in the alt_dum* variables. When I run this, I receive the error message:
"At least one variable has been specified to have both fixed and random coefficients"
Could anyone please help explain why I had this error message?

The syntax works fine without the alternative dummies, or without all the alternative dummies.

Any help is very much appreciated.

Many thanks,
Yen.