Immigration might be good, but does it look good?

One claim about liberalized immigration policy is that it will raise the incomes of immigrants and quite possibly natives, but that average incomes of First World countries will fall.

How is this possible? It’s a matter of averaging two groups together. Suppose you have Country A with 100 people each earning $50,000, and Country B with 100 people each earning $10,000. Then, everyone in Country B moves to Country A and earns $30,000 due to their higher labor productivity in Country A. And in this case, Country B’s labor complements Country A’s labor. So the people of Country A see their incomes rise to $60,000. Both groups benefit. But now the average income of Country A has fallen from $50,000 to $45,000, even though every single person is better off. This is an example of Simpson’s paradox.

So there is a political concern that, even if immigration doesn’t harm natives, it could look like it’s harming natives. What’s the solution? One possibility is publishing another set of income figures: not income per person in America, but average income of native-born Americans. (And average household income for households whose heads are natives, and average hourly compensation for native workers; a variety of measures would exist.) This is the “income per natural” idea developed by Michael Clemens and Lant Pritchett of the Center for Global Development.

Is this dishonest? No. The new figures would be published alongside the old ones, not as replacements. And the concepts these figures refer to are relevant: they reflect how well native-born Americans are doing. If people care about the welfare of native-born Americans, surely these numbers matter. Citizenists want to maximize the well-being of native-born Americans, and if they used numbers for all people living in America, they would come to policy conclusions that are not actually optimal for native-born Americans. Clearly that’s a failure for them.

I think natives probably would benefit on net from liberalized immigration, so I think publishing these statistics would politically help supporters of liberalized immigration. But either way, it would help better depict what’s happening to the welfare of natives.