I am running a panel data regression using the
pdata <- plm.data(RegData, index=c("id","time"))
fixed <- plm(Y~X, data=pdata, model="within")
This question has been asked with reference to other statistical packages such as SAS https://communities.sas.com/thread/47675 and Stata http://www.stata.com/statalist/archive/2005-08/msg00018.html and the common answer has been to use pooled model to get VIF. The logic is that since multicollinearity is only about independent variable there is no need to control for individual effects using panel methods.