Yglesias is making his asshole case for more immigration to the US on the grounds of "national greatness". What's best for global welfare, factoring in optimized economic growth, climate management, etc.? I think the default would be immigration equaling emmigration. Beyond that, what's best for the world? Is there a coordination problem here that needs to be solved. And beyond the US, how should the global population be sorting itself for the global welfare?
Who are the experts thinking about this?