Karl Denninger says house prices over the last 100 years have averaged three times income. What's the implication for us?
This BBC survey says the average semi (a standard unit of housing, one would think) is "worth" slightly over £200,000; official statistics put household income at £33,492. So houses cost around six times earnings.
That suggests a 50% drop is due. But as Keynes observed with wages, house prices tend to be "sticky downward": no-one is in a hurry to realize a big loss on their home equity. Death, divorce and redundancy may force some sales; others may choose to wait, or go for house swaps.
Or wages could double. Up till recently, it was a standard assumption that "inflation" would run at 2.5% p.a. and wage increases 2% above that. Using the "Rule of 72", it would take 16 years of 4.5% wage increases to double nominal incomes.
Whether wages will always rise in real terms, is another matter. One of the effects of globalization is to hold down wages in the developed countries; and food and energy costs look as though they will continue to rise as the rest of the world gets richer and more populous.