Dear all!
My problem concerns the estimation of a conditional logit model. I do have
a choice variable and two independent variables which contain the
utilities of the various alternatives. Formally, I have
Pi(choice_i = j) = beta1*ut1 + beta2*ut2,
in Stata, I used
clogit choice ut1 ut2, group(id)
and everything turned out fine. However, I am not that interested in the
unrestricted coefficients, but I do want to compare and evaluate the
impact of both utility variables. In order to obtain a somewhat
standardized coefficient, both utilities should sum up to one
(beta1+beta2=1). So, the model I am really interested in would be
pi(choice_i = j) = beta1*ut1 + (1-beta1)*ut2.
Does anyone know how to estimate something like that?
Moreover, my question could also be “elevated” to another level. In the
next step, I want to undertake a pairwise comparision of 4 alternative
specific utilities altogether. So, what about
pi(choice_i = j) = beta1*ut1 + (1-beta1)*ut2 + beta3*ut3 + (1-beta3)*ut4.
Does anybody have any idea? Probably, there is any kind of logistic
transformation involved, but I do not have any idea how to do this … Thus
suggestion would be highly appreciated, since I am completely stuck in
that problem.
Best regards,
Guido
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