insheet using hukou.csv, clear
sort hhid line wave
bys hhid line wave: g n=_n //这部是因为如果用duplicates drop做的话,一个都检查不出来
bys hhid line wave: g N=_N
keep if n==N
drop n N
sort hhid line wave
save hukou, replace
clear
use total5
sort hhid line wave
bys hhid line wave: g n=_n
bys hhid line wave: g N=_N
keep if n==N
drop n N
sort hhid line wave
merge 1:1 hhid line wave using hukou
drop _merge
save total6