You could fill libraries with the amount of research that has been done on the root causes of homelessness, as well as the best policy responses to existing homelessness. I'd start with Homelesshub.ca, which is an excellent resource (
https://www.homelesshub.ca/about-homelessness/homelessness-101):
"An adequate supply of safe, affordable and appropriate housing is a prerequisite to truly ending homelessness in the long term. This includes ensuring that people who experience chronicle and episodical homelessness are prioritized and that systems are in place to enable such persons to receive housing and supports through Housing First programs. In a tight housing market, implementing a Housing First agenda becomes that much more challenging. It is also important to address the supply of affordable housing, in order to broaden access for other priority populations, including women fleeing violence, Indigenous Peoples, families, seniors and youth, for instance." (
https://www.homelesshub.ca/about-homelessness/homelessness-101/ending-homelessness)
The best way to sum up the existing research is that housing is a necessary first step to keeping people off the streets. It is virtually impossible to resolve mental health and addiction issues with someone who is not currently in a stable living situation. If you can find the public funds to build massive medical complexes where residents have 24 hour access to on call medical professionals, go ahead. I don't see that investment coming any time soon. But thankfully cheaper options can work for large numbers of homeless, particularly if they can be housed as quickly as possible rather than spending years on the streets.
I'm literally just stating facts. If you choose to interpret all these things about me from a few forum posts, that's on you. And, for the record, I'm a Calgarian who has never lived in Vancouver.
If there's a tone I'm trying to strike, it's brutal pragmatism. Moralistic stances that either demonize or valorize the homeless are a distraction. I think we should give housing to people, even if they're sketchy and hang out with drug dealers, because I think its better than having them live in LRT stations, paying police to constantly chase them around the city, or housing them in extremely expensive jails or hospitals.