*
* Example 16.7.6b starting page 449
*
open data mroz.dat
data(format=free,org=columns) 1 753 taxableinc federaltax hsiblings hfathereduc hmothereduc siblings lfp $
 hours kidsl6 kids618 age educ wage wage76 hhours hage heduc hwage faminc mtr mothereduc fathereduc unenployment $
 largecity exper
*
set lnwage = log(wage)
linreg lnwage
# constant educ exper
*
* Create the dummy variable for non-zero value for kids
*
set kids = (kidsl6+kids618)>0.0
*
* Do the preliminary probit model
*
ddv lfp
# constant age educ kids mtr
*
* PRJ computes the IMR's for the sample using the MILLS option. This is a series
* which can be plugged immediately into the next regression.\
*
prj(mills=lambda)
linreg(title="Heckit estimator") lnwage
# constant educ exper lambda