use "数据.dta"
gen treatment=1 if pro==4|pro==7|pro==1|pro==27|pro==21|pro==12|pro==24
replace treatment=0 if treatment!=1
gen post=1 if (pro==4|pro==7|pro==1|pro==12)&year>=2013
replace post=1 if (pro==27|pro==21)&year>=2014
replace post=1 if pro==24&year>=2016
replace post=0 if post!=1
gen DID=treatment*post
save as "data1.dta"

最后出现invalid 'data1.dta'有知道是怎么回事的吗