The PRs and citizens are all human
They all contribute to the economy
Unless there is a really solid reason why citizens should be favoured over PRs simply because of nothing other than BIRTHRIGHT (which is a pretty iffy thing if you think about, just because a father is a good fisherman does not mean that his son will be a good one)
I don't see any reason why we should practise protectionism of our citizens in any form
Let me ask you a question:
If you were the ruler of a country, and you really could ignore all moral grounds regarding choosing your subjects
Would you rather have a loser bum who was born in your country, or someone who might possibly contribute positively even though he's foreign?
The answer is clear; it is not the place where one is born, it's what he can do for your country