most immigrants come here because their home country had a much lower standard of living - aside from the opportunity. So I am surprised that you took so much trouble; surely Britain has an equivalent standard of living?
I don't think there would be any huge effects if things were basically opened up between wealthy countries... a few would go here from there, and vice versa, and things would balance out. But it is increasingly difficult. Bleagh!
so, only between wealthy countries?