The city already spends a ton of money on the issue - clearly the government just isn't great at putting that cash to use. So I don't think throwing more money at the problem will help. Truthfully the answers to the problem may make the situation worse before it gets better. You should look up an article by Nick Buckley, who runs an outreach service for homeless people in Manchester UK. It's obviously a different situation than SF but it piqued my interest because it's an angle you really never hear.