mymei 发表于 2014-8-6 19:46 
lag(x,k=-1)
occ8 occ9 per pro pub rur south educ tra trad union lwage d81 d82
1 0 1 0 0 0 0 0 14 0 0 0 1.197540 0 0
2 0 1 1 0 0 0 0 14 0 0 1 1.853060 1 0
3 0 1 0 0 0 0 0 14 0 0 0 1.344462 0 1
4 0 1 0 0 0 0 0 14 0 0 0 1.433213 0 0
5 0 0 1 0 0 0 0 14 0 0 0 1.568125 0 0
6 0 0 0 0 0 0 0 14 0 0 0 1.699891 0 0
union_1<-lag(union,k=-1)
> munion_1<-matrix(union_1,nrow=8)
> a<-union==union_1
> a[1:10]
[1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
>
我对面板数据中的union,采用lag(),还是一样的啊