For some San Franciscans, a drug crisis is just part of city living. They see people shooting up in front of their homes and businesses. They often find someone dozing on a sidewalk, high. Sometimes, they check for a pulse. “That’s how I found my first dead body,” said Adam Mesnick, owner of a local deli.

But the city’s drug crisis is relatively new. In 2018, San Francisco’s overdose death rate roughly matched the national average. Last year, its death rate was more than double the national level.

I recently spent time in San Francisco to understand what is going on. In today’s newsletter, I want to explain one of the factors that has contributed to the city’s crisis: culture.

Culture can sound like an abstract concept, but it matters for drug policy. Consider smoking. In 1965, more than 42 percent of American adults smoked cigarettes. In 2021, less than 12 percent did. The country did not criminalize tobacco. And while policy changes like higher taxes played a role, much of the drop happened through a sustained public health campaign that led most Americans to reject smoking.

In San Francisco and other liberal cities, the opposite shift has happened with hard drug use. The culture has become more tolerant of people using drugs. When I asked people living on the streets why they are in San Francisco, the most common response was that they knew they could avoid the legal and social penalties that often follow addiction. Some came from as close as Oakland, believing that San Francisco was more permissive. As Keith Humphreys, a drug policy expert at Stanford University, told me, San Francisco “is on the extreme of a pro-drug culture.”