【发布时间】:2018-12-07 08:48:07
【问题描述】:
我想创建一个变量的滞后。在面板数据设置中,显然只在每个面板内考虑滞后。
为什么plm 的lag() 不尊重面板结构(默认情况下),有没有办法改变它(无需手动 dplyr)?
# Load example data
data("EmplUK", package = "plm")
Em <- pdata.frame(EmplUK, index=c('firm', 'year'))
# how I think it should have worked
Em$lwage_incorrect = lag(Em$wage)
# what actually works
Em= Em %>% group_by(firm) %>% mutate(lwage_correct = lag(wage))
【问题讨论】: