Three causes of California's homelessness crisis

California has the nation's worst homelessness because of a confluence of factors: a decades-long shortage of housing supply built at high cost per square foot, a crisis of untreated addiction and mental illness driven by never rebuilding the mental health system amid cheaper more potent fentanyl and meth, and the fact that mild weather never forced the state to build shelter capacity the way harsh-winter states like New York and Boston did—so California has comparable homelessness rates but far higher unsheltered homelessness.