你好，请问一下，我把非平衡面板数据导入到R里面用plm跑会报错：
> plm(form, data=Data4,effect =  "twoways",model = "within", index = c("Symbol","year"))
Error in Within.default(x, effect) :
  the within function only applies to numeric vectors
In addition: Warning messages:
1: In pdata.frame(data, index) :
  duplicate couples (id-time) in resulting pdata.frame
to find out which, use e.g. table(index(your_pdataframe), useNA = "ifany")
2: In is.pbalanced.default(index[[1]], index[[2]]) :
  duplicate couples (id-time)

3: In pdata.frame(x, index) :
  duplicate couples (id-time) in resulting pdata.frame
to find out which, use e.g. table(index(your_pdataframe), useNA = "ifany")
4: In is.pbalanced.default(id, time) : duplicate couples (id-time)

想请教一下，是导入的数据必须是带有缺失值的平衡面板数据才行吗？

你好，请问一下，我把非平衡面板数据导入到R里面用plm跑会报错： > plm(form, data=Data4,effect =  "twoways",model = "within", index = c("Symbol","year")) Error in Within.default(x, effect) :   the within function only applies to numeric vectors In addition: Warning messages: 1: In pdata.frame(data, index) :   duplicate couples (id-time) in resulting pdata.frame to find out which, use e.g. table(index(your_pdataframe), useNA = "ifany") 2: In is.pbalanced.default(index[[1]], index[[2]]) :   duplicate couples (id-time) 3: In pdata.frame(x, index) :   duplicate couples (id-time) in resulting pdata.frame to find out which, use e.g. table(index(your_pdataframe), useNA = "ifany") 4: In is.pbalanced.default(id, time) : duplicate couples (id-time) 想请教一下，是导入的数据必须是带有缺失值的平衡面板数据才行吗？

变量的格式可能不对。第一步是数据清理、数据准备，数据格式有问题、数据有不正常的异常值，都可能导致运算不出来。

我和你一样的问题，请问题主最后问题jiejuelema