Hi all,

I want to estimate a Tobit model with a binary endogenous regressor. As suggested elsewhere on the forum, I use the user-written cmp command.

However, I am not sure on how to use the predict command after using cmp. When analyzing a simple IV Tobit model with a continuous endogenous regressor, I have different expected values when using Stata's command ivtobit and cmp. Please find below the code to compare the two sets of expected values.

I would like to understand where the difference is coming from. Importantly, the linear predictions are the same for the two commands. The difference is only visible for predicted probabilities and expected values.

Code:
webuse laborsup, clear
        
        ivtobit fem_inc kids (male_educ = other_inc fem_work), ll first
        predict pr1 if e(sample), e(0,.)
        sum pr1

        
        cmp (fem_inc=kids male_educ) (male_educ=kids other_inc fem_work), ind("cond(fem_inc>10,$cmp_cont,$cmp_left)" $cmp_cont)
        predict pr2 if e(sample), e(0 .) 
        sum pr2