There are many contributors to the problem. The horrors of childhood trauma and poverty, mental illness and chronic drug abuse surely add to the likelihood that someone lives on the streets. But Nan Roman, president of the National Alliance to End Homelessness, says the primary cause of the crisis is simple: Housing has gotten way too scarce and expensive.
A few years ago, a team of economists at Zillow found that once cities cross a threshold where the typical resident must spend more than a third of their income on housing, homelessness begins to spike rapidly. When incomes don’t keep pace with the cost of rent, a cascade effect ripples through the housing market: High-income folks start renting places that middle-income folks used to rent, middle-income people start renting places that low-income folks used to rent, and low-income folks are left scrambling.
“It’s sort of a game of musical chairs,” Roman says. “And people who have a strike against them — because they have mental illness or a substance abuse disorder or a disability — are the least likely to get the chair.”
Homelessness wasn’t always this bad. “In the 1970s, there was an adequate supply of affordable units for every low-income household that needed one — and we really didn’t have homelessness,” Roman says.
How California Homelessness Became A Crisis
Planet Money, NPR