I've written several replies and deleted them all. I really can't speculate. its never really occurred to me that that would be a good idea, and everything I wrote was just the kind of unsubstantiated bullshit that I hate reading here.
but governments apparently have roles which are not directly related to collecting taxes to lay sewers, and I think we should maybe be questioning those. and of course there are economic consequences to the population varying, and things start to unravel at both extremes of density.
from this perspective the US was a very good competitor in the attraction of talented citizens. sadly we won't really have a good accounting of what was lost.