But if educational differentials and assortative mating lie behind much of the gap between those in Loudoun County and poorer Americans, they do not explain the Hamptons phenomenon.

ECONOMIST: The United States: The rich and the rest | The

More likely, however, the U.S. savings gap (one of Roach's big scare points) is part of a larger economic or data phenomenon that no one has quite figured out. (Our bullish columnist David Malpass seems ahead on points.) America's growth engine keeps going because lots of capital is available, and at least some of it is being put to more efficient use.

FORBES: Blindsided by Booms