> In the world of immigration policies, letting some specific people in is better than letting no one or everyone in. The middle ground is better than the extremes.<p>I've actually long wondered if this is true.<p>Freedom of movement obviously works at the city level, up to 1 million or so. It obviously works at the megacity level, up to 10 million. It obviously works at the individual state/province level up to 40+ million. It obviously works at US scale (350M). It obviously works at EU scale, 800 million. It obviously works at India's scale, 1.3 billion people.<p>Why is it that if you tried to open the border literally any wider than it is right now, it would all fall down?<p>It's never made sense to me.<p>There are huge disparities in wealth and income within America, right? America's poorest state has a median income of 45K (Mississippi) and it's richest state has a median income of 80K (Maryland). Why doesn't everyone just move to Maryland? Or better yet just move to San Francisco (median 112K). Obviously there's factors other than economics keeping people in place.