In September 2005, the personal saving rate out of disposable income was negative for the fourth consecutive month. A negative saving rate means that U.S. consumers are spending more than 100% of their monthly after-tax income. The recent data are part of a trend of declining personal saving rates observed for two decades. During the 1980s, the personal saving rate averaged 9.0%. During the 1990s, the personal saving rate averaged 5.2%. Since 2000, the personal saving rate has averaged only 1.9%. ; This Economic Letter discusses some of the factors that appear to be driving the secular decline in the personal saving rate. These factors include rapid increases in stock market and residential property wealth, which households apparently view as a substitute for the quaint practice of putting aside money each month from their paychecks. Rapidly rising stock and house prices, fueled by an accommodative environment of low interest rates and a proliferation of "exotic" mortgage products (loans with little or no down payment, minimal documentation of income, and payments for interest-only or less) have sustained a boom in household spending and provided collateral for record-setting levels of household debt relative to income.