[R] Replacing certain rows with values from a different column

I have two columns in a larger data set that list countries in one column and, in some cases, individual provinces within a country or oversea territories in another. I have country population in a second data set that I’m planning to use to calculate per capita rates in the first data set. My i

[R] Upgrading R means I lose my packages

The title says it all. Does anyone know of a way to save your packages when you upgrade to a new version of R? This may seem petty, but I'm accumulating enough packages that having to download and install each of them anew every time I install a new version of R is rather of a pain. Idea