There was no intellectual justification for assuming that the market movements from 980 to 2005 were the best predictor of market movements after 2005. In some ways, this failure of imagination resembles the military’s periodic mistaken assumption that the next war will look like the last one. In the 990s and early 2000s, commercial banks were using lending models for home mortgages that assigned zero probability' to large declines in hous¬ing prices.2 Housing prices had never before fallen as far and as fast as they did beginning in 2007.