RE: Re: st: AW: Question about Heckman Test

["朱琦" <cs_thomaszhu@hotmail.com>]

Dear STATA List! 

When I did the probit in Heckman test, the "norm" function did not work in my STATA. 
Can someone let me know how the norm function as shown below will work?

 probit s age student educat goodhealth
 predict p1, xb
 gen phi=(1/sqrt(2*_pi))*exp(-(p1^2/2))
 gen capphi=norm(p1)
 gen invmills=phi/capphi

Thank you!

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