a comp only in terms of time (12 months), not the number of times that a given sale can be used as a comp - because of this, a "cash out refi boom" followed the low-rate-driven-price-increase - this was the primary vehicle through which developed countries' households leveraged up. On the supply side, home builders are also financed at short rates (in the US, Prime). Their cost of capital was effectively cut in half by virtue of the central bank rate cuts, enabling them to overbuild in response to the rise in prices - with all the new supply making the eventual price collapse worse than it would otherwise have been. In short, the entire episode was straight out of Ludwig von Mises' 'Human Action', Chapter 20, with the new twist that most of the debt was incurred on the consumer side. When rising consumer prices forced the central banks to allow policy rates to rise back up toward market rates, the wind propping up house prices was taken away. House prices immediately declined, ushering in the global financial crisis. Many households, who had reduced their savings out of a belief in the "wealth effect," saw their wealth shrink relative to their debt, and, with less income and more unemployment, especially in the previously booming real estate sector, found it harder to meet mortgage payments. "Strategic defaults" became common, as homeowners with significant negative equity simply abandoned the home and the debt. By the end of 2011, real house prices had fallen from their peak by about 41% in Ireland, 29% in Iceland, 23% in Spain and the United States, and 21% in Denmark. Household defaults, underwater mortgages (where the loan balance exceeds the house value), foreclosures, and fire sales became endemic to a number of economies. Household deleveraging by paying off debts or defaulting on them has begun in some countries. It has been most pronounced in the United States, where about two-thirds of the debt reduction reflects defaults. Of note, Germany, in which almost all mortgages carry 10 year pricing, and in which the 10 year interest rate did not decline during the 2000s, no housing bubble occurred at all. Also, in Canada, in which most mortgages are ARMs but 3-5 year, and which experienced a muted drop in intermediate-term rates, the housing bubble was more muted than in neighboring US. Statistics World Among OECD countries, the larger