It's stated in SAS help, for the utlity statment "UTILITY U(level, )= variables ;", that "The second argument-choices- can be omitted for the first level when all the choices at the first level share the same variables."
Now, if the choices at the first level don't share the same variable, how it can be coded?
For example if in the following codes in first level choice 3 has x1 & x2 variables and choice 4 is related to x3.
Proc mdc data=in;
model decision=x1-x6/ type=nlogit choice=(mode) ;
nest level(1)=(1@1,2@2,3 4@3),
Message was edited by: unity