Immigration

In Monday's Wall Street Journal, Joel Millman has an excellent piece of analysis headlined, "Work in Progress: Prosperity in Home Countries May Not Stem Tide of Migrants to the U.S." His point is that, for a time, economic growth in countries like Mexico and Brazil tends to produce more immigrants.

That's because people with zero skills and zero experience of urban life are not likely to immigrate to an advanced country like the United States. People tend to immigrate when they have developed at least some rudimentary skills and have had some experience navigating the shoals of urban life—and are attracted by the much higher wages offered in the advanced country.

But I take issue with Millman on one point. He writes: "Call it the Development Paradox. The more conditions in 'sender' countries improve, the more emigrants those countries will send, at least until living standards in sending and receiving countries achieve rough parity."

Not parity, I think. Case in point: Puerto Rico. Puerto Ricans are, by an act of Congress passed in 1917, U.S. citizens. There are no legal barriers to their migrating to the mainland. Migration was indeed heavy during the 1950s, almost all of it to New York City. But since 1961, when Puerto Rican incomes reached about 35 percent of mainland levels, there has been no net migration from Puerto Rico to the mainland. That suggests that living standards somewhat short of "rough parity" are enough to stop immigration. I suspect that's the case in Europe too, where incomes are substantially lower in southern Italy than in Germany, but immigration from southern Italy to Germany, substantial in the 1950s, has been negligible now for many years. You are unlikely to uproot yourself from your native land, where you know the language and the customs, for just a few percentage points of gain in living standards. It would be interesting if someone could quantify this.