The main difference w/ Toronto vs SF is that Toronto has a liberal condo building policy so more affordable housing is being built by a (relatively) booming real estate industry. Whereas SF's property development growth has nowhere near reflected its population/income boom.
I can still see some seniors living in older neighbourhoods in Toronto but most of them have moved to the suburbs.
What would probably be reasonable is 1400/mo studio, 2000/mo 1BR, 2800/mo 2BR. What would be ideal is more like 1200/mo, 1700/mo, 2400/mo respectively. Yeah, that's still expensive, but it's a newer building and hopefully older buildings would be around 80% of that. But that's not going to happen.
Some additional policies like penalizing companies for letting new places be unrented for some amount of time, or allowing developers to (temporarily) displace SRO occupants while they demolish and rebuild higher density buildings in the Tenderloin could possibly help change behaviors towards increasing the supply of more modest housing, but that's not going to happen any time soon. In the meantime, the city is fine letting people do what they want at top as long as it benefits the people at the bottom, with no plans to do anything for people in between.
http://sfbay.craigslist.org/search/apa/pen?query=&zoomToPost...
http://en.wikipedia.org/wiki/2013_Stockholm_riots
Sweden. Not exactly a bastion of savage Randian individualism.
Not to say that generous welfare states are of no value, but the available data suggest they are far from a panacea
http://en.wikipedia.org/wiki/2005_civil_unrest_in_France
and London riots/flash mobs:
The European riots are only significant because they're unusual against such comparatively low levels of background violence.
Gentrification doesn't mean pushing all residents and culture out of a place - but it typically flows to areas with the least resistance (and location/ proximity).
So if you have an economically desolate area, and gentrification is at one end of the scale with 'detroitification' at the other - what is in the middle?
Increasingly, you are either rich or poor. A have or a have not. Most HN readers are haves or (because you are still young) think you will be haves. But life doesn't always turn out according to plan.
The most worrying thing is that if you put 95% of the people on a ship's back, it's going to sink; together with its front.