In 2009, after the U.S. housing bubble popped, Nevada's economy lay in tatters. Its unemployment rate was soaring past 12 percent. And so, in response, many residents did the only thing they could do. They left. That year, the state's population shrank for the first time in a century, as former Nevadans fled elsewhere to seek out better economic opportunities in more prosperous states.

It's all Greek to me. (Flickr photo credit: dennoir)

In the 17-member euro zone, however, things aren't quite so simple. Some euro zone nations, such as Germany, are currently chugging along with low unemployment. Others, like Greece and Spain, are hurting badly, with millions of people out of work. But it's not nearly as easy for residents in Greece and Spain to move to where the jobs are. The language barrier is a huge hurdle. According to Eurostat figures (pdf), only 3.9 percent of Greeks and 2.5 percent of Spaniards even speak German. That makes it all the tougher for individual countries to adjust to shocks. (Though, true, some German companies are trying to recruit foreign engineers anyway.)

And these linguistic hurdles are exacerbating the European debt crisis, economist Edoardo Campanella argues in a new essay for Project Syndicate. "[I]n theory," he writes, "workers from the euro zone’s shrinking periphery should flow to the expanding core." But that's not happening. Last year, Campanella notes, 31 percent of Spanish emigrants fled to South America rather than elsewhere in the euro zone. "Europe’s high degree of linguistic fragmentation does not allow the eurozone to absorb a self-inflicted crisis, so people move out of the currency area rather than within it." That leaves the entire continent worse off.

Campanella suggests that — in addition to all the other structural reforms the euro zone needs — the currency union will also, eventually, have to adopt a common language if it wants to survive. "So far," he notes, "political myopia and national interests have prevented European leaders from formulating a common language policy."

But how realistic is a common language policy? A few stats: According to a 2010 Eurostat report (pdf), roughly two-thirds of working-age adults within the European Union said that they spoke at least one foreign language. English is the best-known and most widely taught of all of them. So that's one promising candidate. (The other most popular foreign language, Russian, is mainly spoken in Eastern Europe and is largely a legacy of the Soviet Union.) But that still leaves one third of the population that doesn't speak any foreign language at all. And in some key countries, like Spain and Italy, foreign-language learning remains quite low.

So a single unified language isn't totally inconceivable. But it's still very far from a practical reality—even if the will and desire existed.

P.S. On a related note, Campanella offers up this amusing linguistic analysis of austerity:

In English, as in several other European languages, the term austerity derives from the Greek austeros, which means harsh and severe, whereas for Germans it is merely a technocratic savings scheme, a Sparprogramme.

It's like the currency union equivalent of "Eskimos have a gazillion words for snow..."