use "C:\Users\Asus\Documents\AUCA\Teaching\2022-2023\Econometrics I\Seminars\Seminar 8\Data\wage2.dta" 
regress lwage educ
regress educ sibs
ivregress 2sls lwage (educ=sibs)
ivregress 2sls lwage (educ=sibs), first
reg educ brthord
ivregress 2sls lwage (educ=brthord)
regress educ sibs brthord
ivregress 2sls lwage sibs (educ=brthord)
use "C:\Users\Asus\Documents\AUCA\Teaching\2022-2023\Econometrics I\Seminars\Seminar 8\Data\fertil2.dta"
regress children educ age agesq
regress educ frsthalf age agesq
ivregress 2sls children age agesq (educ=frsthalf)