* ==============
* Card & Krueger 1994
* ==============

use "C:\Users\sovid\OneDrive - The University of Kansas\Lectures\Soc910_AdvStat\examples\cardkrueger1994.dta", clear

gen did = t*treated

reg fte treated t did bk kfc roys 
reg fte i.treated##i.t bk kfc roys 

* Install "diff": ssc install diff
diff fte, t(treated) p(t) cov(bk kfc roys) report