SF is an aberration because relocated high-income earners and rich people move in and raise prices because they out-compete for limited resources by throwing money around (out-bidding real estate) and/or sellers raising prices knowing the upper-crust will still pay them.

SF also is a problem for anyone not making more than $150k/year because it's a magical wonderland where everyone wants to live there, and so they're willing to irrationally sacrifice their financial futures to hang-on to something they can't afford, i.e., paying 50%+ income in rent, unable to contribute 10% to savings, and other forms of financial suicide.

How lower income people make it in SF, even with rent controls, seems like an unsustainable proposition.

I think a better way of measuring of microeconomic affordability is a reasonable budgeted cost-of-living for one person per month in a median housing situation in relation to their potential income. In other words, or thought of another way, the ratio of cost-of-living to income in local nominal dollars.