Prevent future housing bubbles by requiring banks to appraise based on a multiple of equivalent rents, not recent sales.

Houses are an emotional and leveraged purchase which makes prices highly susceptible to available credit.
Banks and the real estate industry take advantage of buyer emotion and encourage families to take excessive risk.
As we have seen, this risk builds until it causes a systemic economic collapse. Repeatedly.
The cycle needs to be broken and house valuations are the easiest place to do it.
Currently, bank appraisals are based on recent sales, which guarantees banks will lend into a bubble.
But, a house has an actual economic value that is easy to measure: what it will fetch in rent.
The buyer of last resort in a bad market is an investor-landlord, therefore banks should be restricted from appraising for more than 13x annual rent.
Without such a change, we are doomed repeat this bubble.