Housing as a Percent of GDP
I liked the graph on CR about the topic.
I quickly ran numbers in my head, 50 years was sustainable, and for housing to get back in line with that it needs to go down another 25% relative to GDP today. If there's a declining in GDP, which I think is probably, then it needs to go down even more.
And, to put that into perspective, for people who don't own a home, that's a pretty big chunk of money that doesn't go to other things in the economy at today's prices.