There is debate over Open Borders vs. more restrictive immigration, but how about some combination of the two options? Please note, I am not advocating this, I just would like to see the discussion become a little broader and also less emotional.
What about open borders for a solid year, followed by a more restrictive immigration policy? This would encourage the arrival of those migrants who were decisive and could get their act together quickly. Of course you can think of many variants on this idea.
I started thinking along these lines in response to the well-known claims that Puerto Rican immigrants under-perform in terms of income because they can so easily go back and forth. So the goal with this proposal is to select for those people who are relatively sure they wish to come and stay.
Another variant therefore would have an exit fee for those migrants who sought to leave and return to their home countries. Imagine a bond posting, with the bond forfeited if the immigrant does not stay say five years.
What about open borders for a month? A week? Who would show up if they had only twenty-four hours to slip in?