pause on
use twoyear
reg lwage jc univ exper
pause
reg lwage jc totcoll exper
pause 
gen a=(.2224/3)/((1-.2224)/6759)
sum a
pause
reg lwage exper
gen b=((1461.7777-1250.54352)/2)/(1250.54352/6759)
gen c=((0.2224-0.0911)/2)/((1-0.2224)/6759)
sum b c
pause
reg lwage jc univ exper
test jc univ
pause
reg lwage  totcoll exper
pause
reg lwage jc univ exper
test jc=univ