can r account for non-individual fixed effects can r include fixed-effects in regression with variables? why use plm regression in R why does plm not work in regression analysis can you use plm to account for non-individual fixed-effects how to use r to include fixed effects why use plm what is r plm used for what is plm in regression can you use plm to account for fixed effects in r can r use plm regression which regression model is an example of fixed effect? why do i need to use plm when in r can r use plm variable what is the purpose of plm package in regression can you account for fixed-effects in r how to use plm variable regression in r can regression use plm in r r use variable plm what is a r variable plm used for