急切求助一个问题，望帮忙

我手里有一个17年的unbalanced数据，请问如何能把它删减成一个balanced？非常感谢！！

最好把数据贴出来，针对数据具体设计操作。

2# sungmoo
版主您好，先谢谢您的热情帮忙，我把数据上传了，不知道是不是您所说的形式，再次感谢

许多pid当wave=17时有两次重复，这代表什么？

4# sungmoo
sorry, no chinses keyboard on this computer. i did not really know why there's repeated observations for wave17.what i have roughly done is:

foreach w in a b c d {
use `w'hid `w'pno `w'sex `w'age pid `w'mastat `w'hgspn `w'qfachi `w'fiyr `w'fiyrl ///
using $dir/`w'indresp
sort `w'hid
save `w'ind, replace
use `w'hid `w'tenure `w'hhsize `w'nkids `w'fihhyr using $dir/`w'hhresp
sort `w'hid
merge `w'hid using `w'ind
keep if _merge==3
drop _merge
renpfix `w'
generate wave = index("abcd","`w'")
save wave`w', replace
}
foreach w in a b c {
append using wave`w'
}
xtset pid wave

Thank you very much for your help and patience! I dont know what really to see, just wish you all the best!