Phil, if you're right that the boom started in '60 then that would correspond with the availability of "The Pill" and all that came with it.
Emancipating women from a life of pregnancies allowed them to become productive outside the home, simultaneously reducing costs running the household [fewer kids] and increasing income. Within a couple of decades the two income family was the norm, families had real disposable income and more and more chose to spend that money on a nice house. Why wouldn't they?
The '80s saw the start of the productivity dividend with rapidly reducing costs of furnishing and equipping the house with a cheaper, more reliable car in the garage. They could sell their house at a tidy profit and buy a better one. Why not?
All these things were one-off though, unless we can send our children to work and/or allow a man four wives out working for him. The engine has run out of steam and there is no easy money to fire it up again. I doubt prices will go back to the long term average because the things I mentioned are real and still there. We have grown a taste for nice homes and will sacrifice to get one, but they will no longer be an investment.
