San Francisco is a failed city. The failure of its prosperous element to do anything about it is an indictment of its entire culture.
[0] http://www.theatlantic.com/business/archive/2014/01/the-geog...
In SF, that probability is 0.122, or 12.2%… extremely high relative to the rest of the country. Atlanta is 0.045, and even New York City is only 0.105.