clipped from www.economist.com

An important reason why the American economy has been so resilient and recessions so mild since 1982 is the energy of consumers. Their spending has been remarkably stable, not only because drops in employment and income have been less severe than of old, but also because they have been willing and able to borrow. The long rise in asset prices—first of stocks, then of houses—raised consumers’ net worth and made saving seem less necessary. And borrowing became easier, thanks to financial innovation and lenders’ relaxed underwriting, which was itself based on the supposedly reliable collateral of ever-more-valuable houses. On average, consumers from 1950 to 1985 saved 9% of their disposable income. That saving rate then steadily declined, to around zero earlier this year (see chart). At the same time, consumer and mortgage debts rose to 127% of disposable income, from 77% in 1990.