The reserve army of the migrants

The latest in the Wall Street Journal's efforts to repackage the Celtic Tiger disaster as itself a triumph --

The Irish exodus is a grim indicator of just how far the Irish economy has fallen. But it's also instructive on how immigrants generally behave when free to come and go as they please: They show up when there's work to be had, and move on if their opportunities dry up. In Ireland's case, both before and after the crash, the result of open borders has been a more flexible and productive labor force. That's an achievement all Europeans can celebrate.

It's true that both the non-Irish and the Irish are leaving the fiscal austerity paradise, but as with Ireland's boom, it's tough to see the general lessons in any of this. The tale of Ireland as an immigrant country is essentially one of movement between the European Union's small economies, especially the Baltic states -- and the crucial factor of Poland. which managed its boom much better than smug and complacent Ireland did and so has been able to create opportunities for its former migrants in Britain and Ireland.

But global migration is not a story of movement between relatively wealthy countries already in an economic union. In particular, it's doubtful there's much in America's immigration debate that can be informed from Ireland.