If you have a lot of time and the issue of San Francisco in particular is something you're interested in, I'd strongly recommend reading this:
http://techcrunch.com/2014/04/14/sf-housing/With regard to what is proposed in that article, the geography of Marin County is such that it would have to look like Hong Kong to sustain a high population density. That won't and shouldn't happen for a variety of reasons.
I'm not in favor of the Manhattanization of San Francisco, although obviously there's a problem that needs to be solved. Plopping down a bunch of skyscrapers would destroy the city. There's no particular reason why new housing stock even needs to
be in the city; it would meet demand at least as well and probably better if it were on the Peninsula. The problem is the lack of a governmental structure for the whole Bay Area, which makes planning at an appropriate scale impossible.
It goes without saying that the solution is not to clear cities of black people to appease the market gods.