clear
set more off
use "/Users/michaelpeters/Desktop/STATATA/DATASET1.dta"

merge 1:1 ID using "/Users/michaelpeters/Desktop/STATATA/DATASET2.dta"

sort _merge

clear
use "/Users/michaelpeters/Desktop/STATATA/DATASET1.dta"
merge 1:1 ID using "/Users/michaelpeters/Desktop/STATATA/DATASET2.dta", update



clear

use "/Users/michaelpeters/Desktop/STATATA/DATASET1.dta"

merge 1:m ID using "/Users/michaelpeters/Desktop/STATATA/DATASET3.dta", update