One under-appreciated topic is the extent to which we dis-incent people to sell their homes as they age. Through prop 13 (in California), and a stepped-up cost basis at death (in the US) - we give people very strong financial incentives to continue ownership.
As a result you have (forgive me) old people who either remain in their homes or rent them out instead of selling them, long after they otherwise would.
I think this is still not as big a factor as the simple lack of building - but it sure doesn't help.
This will be exacerbated by the low mortgage rates which most homeowners are locked in for the next 20+ years. There should be a way to negotiate with the lender holding my mortgage to let me move it to another house for some increase in basis points which would result in a win-win for both sides.
As a result you have (forgive me) old people who either remain in their homes or rent them out instead of selling them, long after they otherwise would.
I think this is still not as big a factor as the simple lack of building - but it sure doesn't help.