I am estimating a double bound dichtomous choice model of willingness to
pay for health services. I am having trouble getting the following
maximum likelihood function to work - stata cannot find initial values
that will yield a nonmissing log likelihood function.
I've done ML check, ML search. I am about to switch methods from LF to
D2 to see if this method will produce better results.
Any suggestions, tips, existing programs out there?
program define dbdc;
args lnf Xb;
tempvar YY YN NY NN;
gen double `YY' = ln(norm(ratelow -`Xb'));
gen double `NN' = ln(norm(rateup- `Xb'));
gen double `YN'= ln(norm(rate1-`Xb') - 1 +
gen double `NY'= ln(norm(rateup-`Xb') -1 + norm(rate1