问答题 The biggest price of the U.S. economy, by far, is the consumer sector. It represents 70% of GDP (国内生产总值) in most years. But consumers suffered historic setbacks in 2008 and 2009. According to a report, 13% of households experienced "substantial financial stress". This compares with only 1% during the previous two recessions. And it is why consumer spending fell so sharply in 2009, as frightened households cut back. It has taken years for total household finances to recover fully, but now they have. Total household net worth is now well above its 2007 peak, driven by the recovery in stock prices and home values. Household debt-to-income ratios are the lowest in more than 30 years. And the first half of 2014 has seen employment begin to take off and the unemployment rate has fallen. The overall outlook for consumer spending, the engine of the economy, is healthy again.