Hi all,

I am trying to get a valuation of a nonlinear expression of my estimated parameters from a mlogit model

. mlogit OS3 A1 North Central South Biol TG Mod Maj ASC ASCConcern Q3Concern, noconstant vce(robust)

The model is estimated and the results are tabulated. Then I want to assess the ratio of the coefficient of TG with that of A1. Namely the coefficient of TG over the coefficient of A1.
I went to the post estimation link or in the command

.nlcom (WTP: _b[TG]/_b[A1]), post

STATA does not provide statistics of the ratio but informs me the following

expression (_b[TG]/_b[A1]) evaluates to missing
r(498);

It seems to me that the coefficients are not stored. Since display _b[TG]
yields 0

Any help will be appreciated.

Peter