fixed.time_IA_tw <- plm(MISPRICING_WIN ~ IA_WIN, data=Final_IA_MISP, index = c("Size_Value_Portfolio", "Date"), model = "within", effect = "twoways")

fixed.time_IA <- plm(MISPRICING_WIN ~ IA_WIN + factor(Date), data=Final_IA_MISP, index = c("Size_Value_Portfolio", "Date"), model = "within")

fixed.time_IA_felm <- felm(MISPRICING_WIN ~ IA_WIN | Size_Value_Portfolio + Date, data=Final_IA_MISP)