st: Biprobit-simultaneous equations

["rob frase" <robfrase@hotmail.co.uk>]

Dear All,

I would be very grateful if you could help me with a conceptual problem.

I am running a Seemingly unrelated bivariate probit model. The commands are 
as follows:

biprobit (Y1 =X Y2 ) (Y2 = X Z Y1)

where  Y1 and Y2 are binary variables. X are covariates common to both 
equations and z are just in the second.
If I have understood correctly,  in a bivariate probit we can ignore both 
endogeneity and simulteneity (Greene 2000, p. 852-3). However, the estimated 
rho is -.99.  Should I be concerned because of this?

Thank you very much and Merry Christmas!
Rob

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