PLM package in R

Question

This is a trivial question; but, I'm new to R; and, none of the tutorials I've seen address it. When using the PLM package in R for my panel data, do I include the cross sectional units, the individuals' variable, in my regression formula? While they don't speak to it directly, the tutorials that I've seen seem to leave that variable out. However, in practice, the results are far more realistic when left in.

Answer 1

The package assumes that the individual and time indexes are in the first two columns. If they are not, use the index argument.

Reference: plm paper (section 4.1: Data structure)