Robert Frank, who covers the wealthy for the Wall Street Journal, says today in his Wealth Report blog (subscription required): "According to data from Moody’s Analytics, the top earning 5% of Americans now account for 36% of consumer outlays. More incredible, this group (with an average income of $342,000 in 2008) have the lowest savings rate in the country: 1.4% compared with more than 8% for the rest of the population. That means that earning more than $300,000 a year save less than one fifth as much as the bottom 40% of earners."
As the Peter G. Peterson Foundation notes, as recently as the early 1980s, Americans saved about 10 percent of their disposable income. (See table here.)