请问您可以帮我看看我计算的周特有收益率代码错在哪里吗?
gen year=substr(week,1,4)
destring year,replace
label variable year "交易年份"
encode week, gen (Week)
sort stkcd year week
order stkcd year week Week return return_m
xtset stkcd Week
gen Lreturn_m1=l.return_m
gen Lreturn_m2=l2.return_m
gen Freturn_m1=f.return_m
gen Freturn_m2=f2.return_m
egen mis = rowmiss(_all)
drop if mis
drop mis
bysort stkcd year: egen n=count(year)
drop if n<30 /*剔除年交易周数不足30周的样本*/
xtset stkcd Week
bysort stkcd year: reg return Lreturn_m1 Lreturn_m2 return_m Freturn_m1 Freturn_m2
predict e,residuals
gen w=ln(1+e)