In the equities-market downturn early in this decade, declining assets were held by institutional and individual investors that either owned the assets outright, or held only a small fraction on margin, so losses were absorbed by their owners. In the current crisis, declining housing assets were often, in effect, purchased between 90% and 100% on margin. In some of the cities hit hardest, borrowers who purchased in the low-price tier at the peak of the bubble have seen their home value decline 50% or more. Over the past 18 months as housing prices have fallen, millions of homes became worth less than the loans on them, huge losses have been transmitted to lending institutions, investment banks, investors in mortgage-backed securities, sellers of credit default swaps, and the insurer of last resort, the U.S. Treasury. In an important paper in 1983, Ben Bernanke argued that during the Depression, severe damage to the financial system impeded its ability to perform its economic role of lending to households for durable goods consumption and to firms for production and trade. We are seeing this process playing out now as loan funds for automobile purchases have withered. Auto sales fell 41% between February 2008 and February 2009. Retail and labor markets too are now part of the collateral damage from the housing debacle. Housing peaked in early 2006. Losses from the mortgage market began to infect the financial system in 2006; asset prices in that sector began to decline at the end of 2006. Meanwhile, equities and the broader economy were performing well, but as the financial sector deteriorated, its problems blindsided the rest of the economy.