use "https://dss.princeton.edu/training/Panel101.dta", clear
gen time = (year>=1994) & !missing(year)
gen treated = (country>4) & !missing(country)
gen did = time*treated
reg y time treated did, r
. reg y time treated did, r
reg y time##treated, r
ssc install diff
diff y, t(treated) p(time)
Note: "treated" and "time" in parentheses are dummies for treatment and time; see the "basic" method
. diff y, t(treated) p(time)
** Type help diff for more details/options
If you have questions or comments about this guide or method, please email data@Princeton.edu.