st: Bivariate probit model with partial observability and survey data

[Eduardo Andrés Alfonso Sierra <ealfonsosierra@googlemail.com>]

Hello everyone

I am estimating a bivariate probit with partial observability
following Poirier (1980), hoping to disentangle the determinants of
the decision to participate in a health related program and the
decision made by the program to accept or reject a person (which, for
some variables might be in opposite directions). Hence, I have two
decision functions that looks something like this:

Y1 = X1*b + X2*c + Ui
Y2 = X1*d +         + Vi

The first one, models the decision made by the person whether or not
to apply to the program.
The second one, models the decision made by the people who run the
program whether to accept or reject the person (and the exclusion
restriction comes from the fact that the people running the program
cannot observe several characteristics of the person applying, which
might actually influence his decision to apply - X2).

Partial observability arises from the fact that I can only observe if
the person participates in the program (Y=Y1*Y2), but not the
decisions Y1 and Y2 independently.

So I am doing something like this in Stata:

biprobit (apply = age male educ healthstatus riskfactors riskaversion)
(accept = age male educ healthstatus), partial

Where apply and accept are both equals to the participation status
(Y=Y1*Y2), as explained in
http://www.stata.com/support/faqs/stat/biprobit.html

After trying several variables, a reasonable model converged (although
it takes quite a lot of time).

Now my problem is that I also have to take into account the survey
design (quite complex I think - two stages, stratified, ...).
According to the survey design, for estimating proportions and other
parameters, I successfully configured the survey data in Stata as
follows:

svyset mysvypsu [pweight=expfact], fpc(mysvyfpc) strata(mysvystrata)
singleunit(certainty) || segment

So, after that I tried running the biprobit with the survey prefix
(svy:biprobit) and it seems it does nothing. It just freezes showing
the message: (running biprobit on estimation sample).

I know that the the biprobit works quite fine with survey data (svy
prefix), because I have used it before, but without the issue of
partial observability (and also with significant fewer independent
variables), but in this case, it is just not working at all!

Any suggestion? Any help or idea would be greatly appreciated!

Thanks in advance,

Eduardo
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