pause on
use wage1
reg wage educ	
predict what1
label variable what1 "Level-Level"
reg lwage educ	
predict lwhat
gen what2=exp(lwhat)
label variable what2 "Log-Level"
gen led=log(educ)
reg wage led
predict what3
label variable what3 "Level-Log"
reg lwage led
predict lwhat2
gen what4=exp(lwhat2)
label variable what4 "Log-Log"
sort educ
scatter  what1 what2 what3 what4  educ, c(l l l l) s(i i i i)