A PA (Production Assistant) is a fancy name for a "gopher", most times. Go 'fer this, go 'fer that.
The errand person, if you will. Fetch coffee, feed the parking meters, go tell so-and-so that something is needed, nip down to Home Depot and get a bag of nails, dash down to Kinkos to have more copies of the shot-list photocopied... whatever "instant" kind of thing may be needed, that is not required to be done by someone further up.
There is no "exactly" what they do.
No idea on how studios treat pay regarding PAs (I would assume they would, though low)... but as far as "indie" productions: Some may get paid, though most don't. Some don't get paid but do a great job, so they'll get called back for the next thing... with some pay. They've proved reliable.
Especially with low-budget indie prods... many times the cast & crew aren't even being paid. Hard to make a case for a PA.
