Here are three properties that most people agree they want, but you can't have all three:
- local democratic accountability
- equal treatment under the law
- ability to absorb a large number of migrants
It's hard to reject the first two, so many jurisdictions have laws limiting immigrants from entering.
I think we should talk about a trilemma for migration, which is three things, and we can only have two out of the three. You think of the liberal democracies — what would we like as a response for large numbers of people who need to go someplace? If it was some political jurisdictions, one of the things we want is local democratic accountability for the officials in the government. The second would be equal treatment under the law. And the third is, in this jurisdiction, the ability to absorb large numbers of migrants, potentially numbers that are bigger than the existing population.
Picture one of these places when there’s a million people there, but you’d like it to be able to accept another 9 million. All three of those things are things that most people would support, and you can’t have all three. So, the two we pick in most existing jurisdictions — we just don’t allow large-scale migration, and you can see some logic to that.
If you’re one of a million people, and you like the equilibrium, and you’re contemplating bringing in another nine million, and you’re committed to equal treatment under the law, the system’s going to basically be the one that all the new arrivals are going to vote for, not the ones that you like. And the new arrivals might be coming for the thing that you like, but still, collectively, they might vote for or put in place something that isn’t the one they’re seeking out.
There’s a reason why democratic systems can’t absorb huge numbers of migrants. You could violate equal treatment and say, “Okay, we’re going to let large numbers of people come in, but they’re not going to become citizens, have a different legal status.” Because of the norms that evolve in these conditions of inequality, I think that is going to prove to be a very damaging approach for both the migrants who arrive and the people in the existing society.
Source: Tyler Cowen and Paul Romer