Media Blame Homelessness on Substance Abuse. The Data Tell a Different Story.

A new study from Pew Charitable Trusts shows that four U.S. cities that saw low rent growth also saw decreases in homelessness.

In California, government officials have blamed the Ninth Circuit decision in Martin v. Boise, which ruled that cities cannot enforce anti-camping bans if they don’t have sufficient shelter beds, for undermining efforts to end homelessness.

As an internal medicine physician based in San Francisco and a National Institutes of Health-funded researcher who has studied the causes, consequences and solutions to homelessness for the past three decades, I know that curing problems requires making both the right diagnosis and prescribing the right treatment. Misattributing California’s crisis to Martin is neither the right diagnosis nor the right treatment.

Homelessness in California is reaching crisis proportions. In the U.S., more than 580,000 people experience homelessness nightly; more than 170,000 of those people are in California. California is home to 30 percent of all those experiencing homelessness and 50 percent of those experiencing unsheltered homelessness in the U.S. Wherever you go in California, it’s impossible to not notice the suffering of people living outdoors, in tents and in cars.

There are many misconceptions as to the cause of California’s housing crisis. For example, there is no credible evidence for the idea, repeatedly parroted by pundits and politicians, that people come to California once they are already experiencing homelessness.

I led the University of California, San Francisco Benioff Homelessness and Housing Initiative’s “Statewide Study of People Experiencing Homelessness,” a rigorous representative study of all adults experiencing homelessness in California. We found that 90 percent of adults who experience homelessness in the state lost their last stable housing in California. A higher proportion of those currently experiencing homelessness were born in California than the state’s overall population.

Others blame California’s homelessness problems on high rates of mental health and substance-use problems. But California does relatively well on these measures. States with the highest rates of mental health and substance-use problems — like West Virginia — have some of the lowest rates of homelessness.

Rather, California’s crisis is due to the exorbitant cost of housing and the extreme shortage of housing available for the lowest-income households. Research in 2022 found the rate of homelessness in a community varies with the costs of and availability of rental housing.

Other factors, such as the rates of mental health and substance-use problems and general poverty, do not explain homelessness rates. California has only 24 units of housing that are affordable and available for every 100 extremely low-income households. The median monthly household income for people experiencing homelessness in the months before they lost their housing was $960 a month, compared with a median studio apartment rent of $1,850 a month.

Some claim that people experiencing homelessness refuse housing or that their problems make them impossible to house. This simply isn’t true. To be sure, people who experience homelessness have high rates of both mental health and substance-use problems. In challenging rental markets, it isn’t surprising that those with substance-use and mental health problems are more likely to become homeless. But this doesn’t mean that they can’t be housed.

Several years ago, colleagues and I conducted a randomized controlled trial of permanent supportive housing — a form of subsidized housing with associated voluntary supportive services — for chronically unhoused individuals with severe mental health and substance-use problems.

The team selected potential participants from those with the most complex problems and approached them when they used emergency services or were leaving jail. Of the 426 individuals that researchers approached, only two individuals declined eligibility screening and one declined the offer. Everyone else accepted.

The data shows that among those randomized to receive housing, 86 percent were housed after four years. Once housed, they remained in housing for more than 90 percent of nights.

Those who were housed — despite not being required to accept treatment — had significant increases in receiving mental health treatment and a concomitant decrease in use of the psychiatric emergency department. This matches other studies showing that when people are offered permanent housing without requiring services, they not only accept and thrive but are more likely to accept treatment.

Others confuse shelter with housing. It is true that more individuals will reject shelter than housing. People experiencing homelessness speak of fears of contracting COVID-19, violence, lack of autonomy, privacy and unrealistic rules as barriers to shelter. Yet interest in shelter outstrips capacity. So, is creating enough shelter for the population the answer?

Clearly, there needs to be more shelter available. But shelters are difficult to site and extremely expensive to operate. Further, those in shelters remain homeless, with all the associated problems. The deficit in housing means that many people will continue to enter homelessness. Diverting funding from deeply affordable housing to shelter will only worsen the crisis.

It has taken decades for California to develop its housing crisis, and it will take many years to fix it. Making the wrong diagnosis and prescribing the wrong solution won’t end the crisis.