Harvard economist George Borjas, perhaps the leading academic skeptic of increased immigration, has started a blog. In a West Side Story-themed post this morning, Borjas argues that the failure of Puerto Rico’s per capita GDP to converge fully with the United States’, despite the fact that the flow of people and capital between the two countries is completely unrestricted, challenges the idea that a liberal migration policy can make people in the developing world better off.

There are also no restrictions that hamper the flow of capital between the two places. Yet despite all these unrestricted labor and capital flows, there is still a sizable income differential between the United States and Puerto Rico. By 2003, price-adjusted per-capita GDP in Puerto Rico was still only two-thirds that of the United States (according to the Penn World Table). Whatever happened to the factor price equalization theorem? If 60 years is not the “long run,” maybe Keynes was right after all.

The fact that migration entails very high costs if an important–and often ignored–part of the economics of migration. The fact that wages don’t equalize even when a “country” loses a large chunk of its population and there are unrestricted capital flows is both interesting and important. It should give some food for thought to those who view migration as a policy tool that can help alleviate many of the developing world’s problems.

I think this is misleading. Mississippi, the U.S.‘s poorest state, has a per capita gross state product of about $28,000 per person, which is not quite 2/3 of the overall U.S. per capita GDP, $43,500. The relevant comparison would seem to be the per capita GDP of Puerto Rico next to that of other Caribbean islands. Puerto Rico’s PPP-adjusted GDP per capita for 2006 was about $19,000.

First, it should be pointed out that the U.S. Virgin Islands, whose inhabitants have been U.S. citizens since 1927, does even less well, at about $14,500 per capita. (That’s a 2004 number, so it’s probably a bit higher than that.) But this isn’t a very good comparison, either; the Virgin Islands has a population slightly bigger than Davenport, Iowa, the economy basically runs on tourism, and the people who own the resorts don’t live there. Cuba, with a population about three times Puerto Rico’s, comes in with a GDP per capita of around $3900, less than a quarter of Puerto Rico’s. But we already knew that communism is terrible. The best comparison is probably the nearby Dominican Republic, which is neither a socialist dystopia nor a U.S. territory. GDP per capita in the Dominican Republic is $8000, less than half Puerto Rico’s.

But who cares about Puerto Rico, the territorial jurisidiction? How are Puerto Ricans doing? According to Wikipedia’s entry on Puerto Ricans in the United States, slightly more Puerto Ricans now live Stateside than on the island, and, “in 2002, the average individual income for Stateside Puerto Ricans was $33,927.”

I find it pretty hard to see this as anything less than a slam dunk for the humanitarian benefit of the freedom of movement.

On a more technical note, why would one really expect wages to fully equalize in the absence of the idealized conditions of the economic model? First, there’s the obvious fact that an island in the Caribbean is “off the grid” of the main U.S. trade infrastructure. Second, as Borjas points out, there is a high cost to immigration. Those able to foot the bill are likely the most productive workers with the greatest capacity to save. And those with higher levels of skill are likely to see a bigger relative returns from participation with U.S. labor markets, reinforcing the incentive for the more skilled to move. If that’s true, and Puerto Rico has lost disproportionately many higher-skilled workers to the U.S., then the fact that GDP per capita is still so high compared to neighboring democracies is really a slam dunk.

To drive the point home, a fun quotation from the the CIA World Factbook entry on the Dominican Republic:

Haitian migrants cross the porous border into the Dominican Republic to find work; illegal migrants from the Dominican Republic cross the Mona Passage each year to Puerto Rico to find better work.

And Puerto Ricans who can afford it “like to be in America.”

[Lyrics to Bernstein and Sondheim’s “America” here.]