I used to build mixed-income housing (one third subsidizes public housing units, one third 80% of area median and one third market rate) for a private partnership to redevelop Chicago's public housing. I can tell you this...fail. Does not compute. Does not work--socially (as an experiment) or financially. The best thing to do is to give mayors the ability to build and get city planners (disclaimer: I'm trained as one) out of the way. Affordable housing cannot be built new, but is usually created as a side effect when replacement units come on line and push down prices in existing units. SF will never be able to accommodate all incomes as long as there is no open-source planning guidelines that are geared to meeting this demand and give developers that " by right" to build. On Oakland, I lived there and it is awesome except for crime and politics and shifty characters. Especially the Quantics [sic]. Oakland can be THAT place, if the above happens here as well. It could, conceivably be better (yeah, I said it) than SF.