That gave the US a booming middle class that until recently was the most important engine of global demand. No longer. Today, somewhat remarkably, US joblessness is higher than in much of Europe.
And the US consumer is mired in high personal debt. As the jobs crisis deepens, so too does US political polarization. Allegations of "class warfare" are a staple of Washington debate. In contrast to the 1960s, dominated by protests for peace and civil rights, today's battles are economic.
Yet there are few signs that either policymakers or economists are closer to finding answers. Indeed, the signs are that the problem is intensifying. In the words of David Autor, a leading labor economist at Harvard University, the labor force is suffering from a growing "missing middle."
Read more in the Financial Times.