Correlation does not imply causation.

Physical illness and drug addiction (and even mental illness in some cases) are more likely a symptom of homelessness than a cause.

From accounts I've heard from homeless people, one of the biggest problems homeless people have is boredom. This leads to both depression and drug use, both of which can lead to both physical and mental illness.

In fairness to all in this thread, I think the failure to define "solving homelessness" is causing some miscommunication.

The OP seems to be discussing the problem of solving it in a global sense, so that people do not become homeless. IMO, more housing is the solution to that problem.

The GP seems to be discussing the problem of solving it in terms of the existing homeless population, which, regardless of causation or the directionality of any causation, does require dealing with the mental illness and drug abuse issues.

> The OP seems to be discussing the problem of solving it in a global sense, so that people do not become homeless. IMO, more housing is the solution to that problem.

IMO, it's not, because people don't become homeless (for the most part) because there are no existing vacant housing units, they become homeless because of joblessness, poor credit, drug addiction, mental illness, and criminal issues (often involving drugs), or a combination thereof, which make them unable (financially or otherwise) to either rent housing in the open market or take advantage of publicly operated or subsidized housing.

No, those are largely myths and where they are true are in places without large homeless populations. We are talking about homelessness in San Francisco which is primarily caused by zoning issues, gentrification, and similar issues.

> ... which make them unable (financially or otherwise) to either rent housing in the open market or take advantage of publicly operated or subsidized housing.

This is made easier when there is more housing available.

Correct, but housing is a very important requirement.

Yeah because people who have homes aren't mentally ill. /s

Being physically ill isn't a correlation of having neither money nor a home. /s

Being addicted to drugs isn't a symptom of mentally checking out to avoid the problems you're literally unable to address. /s

Edit: yes, you're right, it's a lot more complicated than just housing. But housing, I think, is a big cause.