What is it, really, that makes a country great?
Surely not size. Russia has 56 times the territory and more than twice the population of Italy. Yet Italy’s economy, troubled as it is, is 44 percent larger than Russia’s.
Nor is it sheer scale. China’s G.D.P. may eventually outstrip America’s. But per capita Chinese G.D.P. is lower than Mexico’s, making it a rich country of relatively poor people.
Raw military power? Vladimir Putin controls what is probably the world’s largest nuclear arsenal, capable of blowing up the world many times over. But the Russian Navy can barely operate a single aircraft carrier far from its shore.
A better measure of national greatness is the ability of nations to cultivate, attract and retain human capital. People tend to vote with their feet. To trace the rise or decline of nations is to watch where those feet go — and where they leave.
Take Hungary. Since 1960, seven Hungarians have won the Nobel Prize. Not bad for a small country — except that all of them left Hungary to make their lives and careers elsewhere.
Or take Portugal, a once-great country. Today, one in five Portuguese citizens — two million in all — live abroad. More Portuguese live in France than in Lisbon. That shouldn’t be a surprise: Since 2008, the Portuguese economy has shriveled by 4 percent.
The United States provides the opposite example. The American economy is 12 percent larger today than it was at the time of the financial crisis. We’re also taking in roughly half a million legal new arrivals a year. The foot-voting continues, and we’re still coming out on top.
As for Nobelists, a report by George Mason’s Institute for Immigration Research found that Americans have won 40 percent of all Nobel Prizes ever awarded — and immigrants accounted for 35 percent of those winners. Last year, the only native-born American to win the prize was Bob Dylan, for literature. The rest of the American winners — economist Oliver Hart, physicist J. Michael Kosterlitz, chemist Fraser Stoddart — are immigrants.