One of the annoying parts of this is partly that there’s a lot of debate and talk about what to do about homelessness, and various political groups with opinions on the matter rattle off causes, but don’t mention the numbers to paint a clear picture of the causes and the size of the problem. When I
do run across a source that attempts to list causes in order of how common they are, mental health and addiction aren’t in the top 3 causes for individuals. Some cities this could be different as each region will have a slightly different mix, but things get a bit weird when you do find data. While
this page cites 35% of homeless face substance abuse issues, they do stress that it’s not necessarily the cause of the homelessness, but can also be a symptom of it. Looking at more data further down the same page from Houston, under 10% of the sample there is attributed to substance use as the cause of their homelessness, with unemployment being listed as over 33%. At least in Houston, you’re more likely to be evicted by a family member, fleeing abuse, or just unable to find housing after being released from prison. If we assume the different two samples are representative enough to be roughly comparable (an admittedly tricky thing to do), this seems to say that the majority of homeless people with substance problems developed it after being subjected to homelessness.
That suggests you can make a good dent in the substance use side of things by tackling underlying root causes of homelessness directly.
Is this truly a given though? In this very thread there’s the admission of the stigma associated with both of these. Mental health services are limited, and can be expensive with limited help from insurance or the like (i.e. unaffordable by those in this situation that need it). Drug addiction is
criminalized in the US, one factor
feeding a cycle of jail and homelessness. Folks coming out of the justice system face discrimination in employment and housing, making them more likely to be homeless. People that are homeless are more likely to have to interact with the justice system, for a variety of reasons, including laws that punish visible homelessness.
I think you can make a bigger dent in this than is being suggested in this thread with reasonable policy changes, if hard to find the political will to actually make those policy changes. But so long as housing in our society is treated as a privilege, rather than a right, I don’t disagree it will be difficult to stamp out homelessness when so many people are having to live paycheck to paycheck, can be discriminated against when renting, etc.
In the vein of affordable housing, I’d argue that the common policy of US cities that rely on urban sprawl and car dependence doesn’t help here. R1 zoning rules make it harder to build housing without ever more sprawl, when we should be adjusting zoning rules to allow for more density, and mixed-use construction. We need more zoning that exists between suburbs and urban core. Car infrastructure also happens to eat up land that could be used for infill construction, requiring more sprawl and spreading apart services, feeding car dependence (so does underfunding public transit, but that’s a separate, if related, topic).