I don't disagree, getting smart and ambitious people to move to your country is a really good policy overall. It is just worth weighing it against the opportunity cost for the citizens of the country.
One thing I seldom see discussed is how if you're attracting the best and brightest it is leaving the original country poor. These places invest in their children hoping that they'll start businesses and then all that investment just ends up going to those countries that are already the richest.
I certainly don't blame anyone for wanting to move to improve their situation (I did it too!) but I wonder if developing countries would have caught up to the West decades ago if this brain drain wasn't going on.
Because their country doesn't offer the same opportunities to achieve the things they believe they can in their new country. It's the main reason people emigrate. No one's going to build Nvidia in India or China, for instance, at least not back in the time that it was created in America.
Kind of ironic, considering the whole original population of America (the whole continent) was mostly replaced by immigrants, starting some time after 1492 AD.
That's false. By definition none would have come if there wasn't opportunity. You don't need to be a geography student to see that it wasn't just irreligious opportunity.
That's not how it works. It depends on whether (how much) they are paid and if so what do they buy with that payment. Are they settled in US buying pizzas and Netflix?
Because if not, then investments to Nigeria past $x will grant it the upperhand since all that money can get you another doctor and more.
I certainly don't blame anyone for wanting to move to improve their situation (I did it too!) but I wonder if developing countries would have caught up to the West decades ago if this brain drain wasn't going on.