Understanding the evolution of real-time beliefs about house price appreciation is central to understanding the U.S. housing crisis. At the peak of the recent housing cycle, both borrowers and lenders appealed to optimistic house price forecasts to justify undertaking increasingly risky loans....

An expansion in mortgage credit to subprime borrowers is widely believed to have been a principal driver of the 2002-06 U.S. house price boom. Contrary to this belief, we show that the house price and subprime booms occurred in different places. Counties with the largest home price appreciation...