Mainstream reporting on SF’s homeless issue by and large indicates the majority of the city’s homeless are San Franciscans. For example, in May, The Standard wrote that “71 percent of [homeless people] surveyed reported living in San Francisco, 24 percent in other California counties, and four percent outside of California.” In June, Vox reported that “the vast majority of those homeless in California (nine out of 10) had been living in the state before losing their homes — bucking the idea that maybe people are flocking to the sunny West Coast to live outside in the nicer weather.” More recently, city supervisor Dean Preston told UnHerd that “the biggest driver of why folks are on the street [in San Francisco] is because they lost their jobs, income, or were evicted from their homes.” 

Mainstream reporting on where exactly SF’s — and California’s — homeless are from is based on two canonical sources: surveys from the Department of Homelessness and Supportive Housing (HSH), and a study of 3,200 homeless people in California, conducted by the Benioff Homelessness and Housing Initiative at UCSF. However, both suffer from flawed methodology that renders their data completely unreliable — though even this unreliable data still suggests most homeless in San Francisco aren’t from the city, and that most homeless in California are from out of state.

Every two years, over the course of a single night, HSH volunteers walk around the city, counting the number of people they see sleeping in cars and on the street. This is called a “Point in Time” (PIT) survey, and it’s a federally mandated requirement for receiving federal funding for homeless services. During the weeks following the PIT headcount, homeless people are surveyed “in order to profile their experiences and characteristics” (the most recent of which surveyed 768 of them). These two evaluations form the basis for the data the HSH publishes in its “comprehensive reports.”