It's well-established by now
Except it isn't, except in the minds of racists like yourself (and no, claiming to not be a racist is not sufficient to actually not be a racist). There is plenty evidence to the contrary and the economic effects of migration are a second order effect to the tsunami of change unleashed by technological change. Good day to you.
How do you know
You don't and can't, and if that's a problem for you, you don't use Gogle services. Next!