R - Error in class(x) - plm - only within and random effects models
问题 I have run into some difficulties with the plm function in R. I am trying to run different panel data models on the same dataset and it works with the "between","fd" and "pooling" models, but not with the "within" or "random" models. Not sure what I am doing it wrong. Below is my code and the error message that I get. Would be grateful for any help!! pdata_1<-pdata.frame(mydata_1,index=c("Country","Year")) fd<-plm(Y~Category+Eurozone+Poverty_Rate,data = pdata_1,model = "fd") pooled<-plm(Y