"In this postmortem, I find that the design, implementation, and maintenance of financial policies during the period from 1996 through 2006 were primary causes of the financial system's demise. The evidence is inconsistent with the view that the collapse of the financial system was caused only by the popping of the housing bubble and the herding behavior of financiers rushing to create and market increasingly complex and questionable financial products. Rather, the evidence indicates that regulatory agencies were aware of the growing fragility of the financial system associated with their policies during the decade before the crisis and yet chose not to modify those policies"--National Bureau of Economic Research web site.