Yeah it's an interesting and tricky issue. At heart I'm also in favor of free movement: I'm an immigrant myself after all, I live in a cosmopolitan city and I

Yeah it's an interesting and tricky issue. At heart I'm also in favor of free movement: I'm an immigrant myself after all, I live in a cosmopolitan city and I enjoy being surrounded by diverse cultures. At the same time, I'm not sure that truly unfettered freedom of movement would create a world which we actually want. For instance, if all border enforcement disappeared tomorrow, I don't see how there wouldn't be a mass immigration from regions at the bottom of the development index toward those at the top. And I would imagine the result of that would be to torpedo the cost of labour, and put stress on the social systems in those developed countries. I would imagine the wealthy would be just fine, but the middle class would be all but erased globally. So while I don't necessarily like the idea of boarders and exclusion, at some level I don't see how healthy and prosperous communities/cultures/societies can preserve their health and prosperity without having some filtering mechanism. And as far as the options you give, I would agree with you in broad terms that we should strive to allow people to preserve what's unique and interesting about their cultures when they move into our communities (option 4), but the truth is there are a lot of gray areas and there will probably always have to be some of #1 as well. For example, lets say that there is a population which moves into your neighborhood in Seattle which doesn't believe in vaccinating their kids, and now your kids who go to the same school are at risk of getting the measles. Is that enforcing your cultural superiority to insist that they get vaccinations against their belief system? Or say there are people moving into your neighborhood who strongly reject homosexuality in their culture, and now your gay friends have to deal with dirty looks when they walk down the street holding hands in their own neighborhood. Should you just accept this as a form of cultural diversity? So I think what I'm trying to say is that it's a nice idea to say we should open the borders and live and let live, but it's not as simple as that. A lot of us would probably agree that we're happy if people who share mostly the same values as us, and are of a similar socioeconomic strata come and bring their food, music, maybe even their language. But when it comes to real-world migrations I think there are a lot of grey areas, and we all have to draw the line somewhere as far as what should be accept as far as changes in our communities, but there's a lot of disagreement and negotiation involved in exactly where that line should be. Anyway, like I say I don't know the answers, and it's a topic I struggle with philosophically.