[Taqwus]

Plundering also makes sense when the population's going to rapidly die off anyway, such as when you're playing a non-Broken Empire Ermor, or Carrion Woods Pangaea. They're doomed anyway, so you might as well get some more money out of 'em.

If your opponent doesn't have highly mobile reaction force, you may in other situations be able to pillage for a little while... although in such a situation it might be better to set taxes to 200% and move on to another target, if you can. OTOH, if it's an especially valuable province to your victim (say, the only high-pop province for a while, or it provided some valuable indy troop that he'd been making heavy use of) you may plunder AND tax to drive up income and lower pop for as long as you can. *shrug*