Code R Khoa Luan

library(readxl)
data <- read_excel("~/Documents/Khoá luận/5bien.xlsx")
View(data) 
data <- na.omit(data)
summary(data)
install.packages("plm")
library(plm)
pdata <- pdata.frame(data, index = c("id", "Year"))
pdata$L1_X2 <- lag(pdata$X2, 1) 
data <- na.omit(data)
summary(fe_model <- plm(Y ~X1+L1_X2+X3+X4+X5 , data = pdata, model = "within"))
summary(re_model <- plm(Y ~X1+L1_X2+X3+X4+X5 , data = pdata, model = "random"))
phtest(fe_model, re_model)