collinearity and Heteroscedasticity in bivariate probit model


New Member
Hi, all

I run a bivariate probit regression, and I am not specialized in statistics and I dont know how to check collinearity and Heteroscedasticity in the mentioned model.

and how do I solve it if it exists ?

in fact I use many samples and sometimes stata 8 drops a variable for collinearity but when I compress the constant, stata dont drop the mentioned variable.

for example is it usful to use Heteroskedastic probit model
from binary outcomes window, and how to use it.

if I have to run a linear regression to test that how it could be with a two dependent dummy variables.

Please help its very urgent
any participation will be highly appriciated.
thanks in advance