At a recent city hearing, San Francisco officials celebrated the findings of an academic study examining a ban on late-night convenience stores in the Tenderloin.
Citing the study, Supervisors Matt Dorsey, Bilal Mahmood and Alan Wong voted unanimously at the Jan. 22 meeting of the Public Safety and Neighborhood Services Committee to broaden the late-night convenience store curfew, which had only applied to the Tenderloin, to parts of the South of Market area.
Dorsey said the study “offered academic validation” that the pilot program, which was adopted in July 2024, had reduced crime in the area, and police Capt. James Aherne testified in support. In fact, the study showed such success, the supervisors said, it was evidence the ban should be expanded into SoMa.
But Mirko Nazzari, a criminologist at Italy’s University of Sassari and the study’s lead author, was more cautious.
As the full Board of Supervisors gears up to vote on expanding the curfew on Tuesday, Nazzari said the findings of a study being used to support that effort are are preliminary, and limited.
“This was just a first attempt to provide empirical evidence because it was a policy instrument that affected many, many business owners,” said Nazzari. “We wanted to provide some evidence to guide the policy debate, but again, it was just preliminary and interim, and we really need to do much more on this.”
Riley Tucker, a criminologist at Penn State University and one of the experts cited in the study, went a step further. “I wouldn’t say this is proof that this policy should be expanded anywhere else,” said Tucker. “There’s a lot more to uncover.”
Furthermore, Nazzari said, the study suggests that the ban may have caused crime to spill into SoMa, raising the prospect of a broader ban displacing crime to even more areas.
The Tenderloin curfew, introduced by then-Mayor London Breed in 2024 and passed by the Board of Supervisors, banned certain businesses, like liquor stores and smoke shops, from operating in the Tenderloin between 12 and 5 a.m. in an attempt to reduce drug-related crime.
The study looked at data from the first nine months of that ban, and estimated a 56 percent reduction in drug-related incidents during curfew hours. It also found “no evidence of spatial displacement to nearby areas or temporal displacement within the Tenderloin Public Safety Area.”
But it did find a potential increase in crime in SoMa during outside that midnight to 5 a.m. period, suggesting that drug incidents may have spilled southward from the Tenderloin.
The study aimed to understand what crime levels in the Tenderloin would have been like if policymakers had not implemented the convenience store-curfew program. It also assessed whether drug-related incidents had increased in other neighborhoods following the curfew.
Researchers analyzed crime data from 11 out of 37 San Francisco neighborhoods during the curfew program — six border neighborhoods and five randomly selected neighborhoods — and compared those to the Tenderloin. That’s when they spotted a potential increase in crime in SoMa — an increase that might be attributable to the ban.
Nazzari said the results were “interesting” given supervisors were considering expanding the ban to SoMa. Either way, he stressed, “these are just preliminary results, and we really need to look into that.”
The city’s current and former police chiefs and Mayor Daniel Lurie have all said that police enforcement in some parts of the city frequently pushes crime into others. In the past year, increased policing of the Tenderloin and SoMa have pushed more drug-dealing and drug use to the Mission.
“I don’t want to keep chasing,” Lurie told Mission Local in 2025. “But we’re going to have to do it for a little bit until people around the Bay Area, around the country and around the world realize that San Francisco is no longer a place you come to deal drugs or to use drugs on the streets.”
Tucker, the Penn State University criminologist, said it’s hard for him to imagine that the curfew program did not similarly push drug-related activity into other neighborhoods. “I really don’t think the intervention stopped people from buying and selling drugs, so it’s a question of, ‘Where did they do that?’” he said.
That said, he added, the study’s estimates would be more conclusive if the researchers had compared crime levels to the entire city, not just 11 discrete neighborhoods. He also said the study’s findings are limited by the fact that researchers did not control for social factors in the neighborhoods, like income levels, which tend to be strongly correlated with crime levels.
“If they’re not controlling for these things in the model they use to simulate how much crime is going to happen, it’s missing a major factor you would use to predict that,” he said.
Nazzari acknowledged that the study’s findings are limited by its lack of socio-economic data, and by the fact that it only examines drug crime within a five-hour window, within specific neighborhood areas and within a limited period of the curfew.
The city is cracking down on late-night stores in the area in other ways. On Thursday, the city attorney’s office announced its prosecution of nine Tenderloin convenience stores it alleges were fronts for gambling and drugs. The press release connected the litigation to the supervisors’ push to expand the curfew, suggesting that it is part of a broader crime-deterrence strategy.
“These convenience stores were magnets for drug activity, and, in some cases, the stores were selling illegal drugs themselves,” City Attorney David Chiu wrote in the release. “Most businesses contribute positively to our neighborhoods, but a handful of late-night retail establishments, like the ones we have shut down, attract significant criminal activity.”
Both Nazzari and Tucker said that business curfews are something of a civic trend — one that social scientists are still working to understand. In recent years, cities across the United State, including New York and Miami, have turned to business curfews as a strategy to curb local crime and disorder.
So far, said Tucker, their effectiveness remains unclear. “Policy-wise, this is such a hammer for the whole neighborhood.” But, he added, it’s much easier for a city to implement a curfew than it is to deal with the larger problems that cluster public drug markets into certain areas.
“I don’t think a single city government can address neighborhood segregation and poverty,” said Tucker. “So local governments are always trying to grasp at the levers they can pull.”