Visible Homelessness in SF: A Quick Breakdown of Causes

The US is the richest country on Earth, excluding small states like Singapore with <10 million people. And the Bay Area is one of the US's economic hubs.

To highlight out how absurdly rich the Bay Area is, the BEA states that the San Francisco-Oakland-Berkeley Metropolitan Statistical Area had a total GDP of $588,335,543,000 as of 2020, with a population of 4,739,649 as of 2020, according to the Census Bureau. This means that the GDP per capita of the SF metro area was $124,130 in 2020, higher than Singapore, Norway, Ireland, and Switzerland.

But it gets crazier. If you look at just San Francisco county (which basically just includes the city), then its GDP is $201,547,346,000. With a population of 870,014, that means the GDP per capita of San Francisco is a mindboggling $231,660, richer than Luxembourg, Monaco, and Liechtenstein, and every other micronation for that matter.

The idea that solving homelessness in the Bay Area is a matter of just making the city richer, is false. There’s more than enough money.

From what I understand, there are two fundamentally different types of homelessness. One is when someone "normal" is just down on their luck and who then tends to live with their friends until they get a new job or something. The other is when someone is severely mentally ill, to the point where it seriously interferes with their functioning in society, which leads to the sorts of homelessness you see on the streets.

When you analyze the correlation between homelessness and housing prices, are most of the cases of homelessness of the first type or of the second type? Is the association equally strong for both types?

Thanks for writing this!

I've been thinking about homelessness/crime/related social dysfunctions in SF a good bit lately, as I think about moving to Berkeley, and its good to have some hard data put together in one place with relevant context. I've noticed that all I have to go off of on the wider internet, unless of course I go and directly do the research myself, is adversarially selected anecdotes [LW · GW] that play into the red and blue political tribe agendas, and I'm epistemically afraid of updating on information selectively filtered like that. This is also probably the single best concise stab at explaining causes of SF's homelessness I've read, as explanations are likewise epistemically distorted by the existence of political tribe pressures -- I've now updated towards SF zoning laws being the chief cause of SF homelessness.

SF’s housing costs are 3.3x higher than the US average. Plotting it on this line,

This feels dubious to me. I think there's no a priori reason to assume the correlation is similar for cities as for states.

A full-on Simpson's paradox with reversed correlation seems unlikely, since I guess rich cities are typically in rich states. But I could easily imagine something like: "the housing costs of the state are basically irrelevant, the housing costs of the city matters a lot. When you bin cities into states, you're introducing noise that makes the correlation seem weaker than it is". And I wouldn't be completely shocked by something the other way around, where the housing costs of the state matter a lot more than the housing costs of the city. In which case SF would only get the same multiplier here as anywhere else in California.

Still, if this is the data you had, plotting it on this line seems clearly better than not doing so.

I'm interested to see how Prop C changes things. Proposition C was passed in 2018 and taxes companies that made over 50 million dollars a year so that they contributed money into a fund specifically for ending homelessness. Normally the city budget includes money to create a thousand units of housing for homeless exits, whether the city is buying property to convert into permanent supportive housing or putting money into rent subsidies. A year ago the June budget was able to access the prop c money, and the budget included 4,000 units of housing for homeless exits. About 5,000 people a year become homeless in San Francisco. I did a research project last summer and found that indeed 20% of them are able to be housed through the coordinated entry system. So it'll be interesting to see how that number changes with the Prop C money. Though homeless advocates have to constantly fight with the city to make sure the money is used for homeless exits and not services for homeless people that don't actually help them get housed (like food).

(The research I was doing: https://www.cohsf.org/a-new-coordinated-entry-shifting-from-a-system-of-scarcity-to-assessing-real-needs/)

Curated. On one hand, this is a sort of niche, political topic. But I think "how does homelessness work?" is relatively generalizable, and I appreciate Alyssa weighing into the topic with a straightforward, data-driven fact post [? · GW] style approach. 

Measuring homelessness by state seems like a deeply flawed approach given that it involves aggregating enormous geographic areas with different conditions. 

One factor not mentioned yet is that the homeless are allowed to reside on the streets of SF. 

The streets are someone's property (usually - municipal property), and the property owner can implement and enforce rules that ban the homeless from residing there. For example, under a threat of incarceration (including mental hospitals, addiction treatment centers etc).

I don't know if it's a good idea to implement such rules (I haven't thought deeply about it). But it could greatly contribute to the difference in visible homelessness between, say, SF and Beijing. 

"I also found that, controlling for rents, the partisanship of a state did not predict homelessness""

Did Partisanship correlate with rents if so what direction?

Good post, it makes me think a lot of the homeless crisis is more literally "I can't buy a home". 

I wanted to add a (possible, additional) factor in that I didn’t see included, although I don’t know how you would test it. Guess: because of the size and interconnectedness/maturity of SF’s homeless network, it might be easier to be less isolated/more connected while homeless in SF than in other places. It seems clear that in some parts of SF (I’m thinking of particular streets in SOMA and the Tenderloin, and at Civic Center) the people who live on the streets are connecting with each other and also often enjoying each other’s company. They look like friends. And this may be part of what makes the homeless population more visible in SF than in other places—they’re hanging out together, often talking loudly, and they’re often in the same place all the time, every day. There is a social scene it is possible to be part of, and this might feel better than living alone somewhere much nicer.

(There are still many people who seem both isolated and homeless, too.)

Thank you! Very clean and solid analysis.

Would it be easy to do the same analysis, but with housing vacancy rate instead of housing costs? Spoilering my prediction to avoid biasing results

I also found that, controlling for rents, the partisanship of a state did not predict homelessness (using the Partisan Voting Index)

This is not a useful way of looking at this; homelessness would be almost entirely controlled by city, not state, policies. State partisanship in large part measures not how blue or red the states' cities are, but rather how urban or rural the state as a whole is.

I'd love to see a Github version of this post. I'd be interested in re-running the same data to generate results for other cities (e.g. Seattle).

Or maybe some-such site/notebook already exists?  If so, please do tell!

I don't buy the housing cost / homelessness causation. There are many poor cities in the US that have both low housing costs and high homelessness. This page mentions Turlock, CA, Stockton, CA, and Springfield, MA as among the top 15 places with the highest homelessness rates; a quick Zillow search indicates they all have a fair bit of cheap housing.

The relationship between homelessness and state-wide housing costs is probably caused by a latent variable: degree of urbanization. Cities are both more expensive and have more homelessness, and states vary widely along the urban/rural dimension.

You also missed a strong countervailing factor which would tend to reduce SF's homelessness: demographics. SF is has fewer blacks than the nation as a whole, and blacks are more likely to be homeless. SF is also disproportionately Asian, and Asians are much less likely to be homeless.

I think SF's homelessness problem is caused by a very simple reason: SF is a relatively pleasant place to be a street person. This is partially because of the weather, as you mentioned, but also because the city is quite tolerant of the homeless population and has a lot of services for them.

Note that, since these causes are multiplicative, percentage here is calculated by first taking the log, then dividing

Could someone explain why you do this? 

Does San Francisco look like more of an outlier if you plot unsheltered homeless vs house price?