*
* Example from 8.3.3 starting on page 208
*
open data cps2.dat
data(format=free,org=columns) 1 1000 wage educ exper female black married union south fulltime metro
*
linreg wage
# constant educ exper metro
*
linreg(smpl=metro) wage
# constant educ exper
compute ssqmetro=%seesq
linreg(smpl=.not.metro) wage
# constant educ exper
compute ssqrural=%seesq
*
set spread = %if(metro,ssqmetro,ssqrural)
linreg(spread=spread) wage
# constant educ exper metro