A remark by Greenspan symbolizes concern that wealth disparities may destabilize the economy.
The income gap between the rich and the rest of the US population has become so wide, and is growing so fast, that it might eventually threaten the stability of democratic capitalism itself.
Is that a liberal's talking point? Sure. But it's also a line from the recent public testimony of a champion of the free market: Federal Reserve Chairman Alan Greenspan.
America's powerful central banker hasn't suddenly lurched to the left of Democratic National Committee chief Howard Dean. His solution is better education today to create a flexible workforce for tomorrow - not confiscation of plutocrats' yachts.
But the fact that Mr. Greenspan speaks about this topic at all may show how much the growing concentration of national wealth at the top, combined with the uncertainties of increased globalization, worries economic policymakers as they peer into the future.
"He is the conventional wisdom," says Jared Bernstein, senior economist at the Economic Policy Institute, a liberal think tank. "When I'm arguing with people, I say, 'Even Alan Greenspan....' "
Greenspan's comments at a Joint Economic Committee hearing last week were typical, for him. Asked a leading question by Sen. Jack Reed (D) of Rhode Island, he agreed that over the past two quarters hourly wages have shown few signs of accelerating. Overall employee compensation has gone up - but mostly due to a surge in bonuses and stock-option exercises.
The Fed chief than added that the 80 percent of the workforce represented by nonsupervisory workers has recently seen little, if any, income growth at all. The top 20 percent of supervisory, salaried, and other workers has.