Many people aren't sold on that notion. I can't see how bring people from vastly different cultural backgrounds, many of whom won't speak the language are going to benefit the economy.
So, I hope we don't get too clever about it.
Sorry, 50k is not massive, let's talk about a couple of millions.
The only common factor being their economic status.
But the Arab French have integrated culturally and are highly successful artists, athletes, businessmen, etc. Its only a matter of time before they deliver on the promise of immigration.
P.S. I'm a Muslim of South Asian origin born in Saudi Arabia.
edit: No, we actually don't, my mistake. But there seems to exists unofficial expulsions and regularization quotas to meet every year.