(NewsNation) — In 2016, the city of New York embarked on an ambitious experiment aimed at improving safety at public housing facilities.
“(Mayor Bill DeBlasio’s) administration was focused on public housing communities where a lot of the crime is concentrated in the city and trying to find ways to improve those communities either through more social services or environment cleanup, and lighting was one of those things they were interested in,” said Aaron Chalfin, a criminologist based at the University of Pennsylvania.
The city placed temporary light towers outside some public housing developments. These diesel-powered towers were no ordinary street lights. They were much brighter, emitting around 600,000 lumens (the standard measure used for brightness); for comparison, many typical street lights might emit something closer to 5,000 lumens.
“It’s sort of like lighting up an area like Yankee Stadium,” Chalfin said, describing the lights. The lights were originally supposed to stay in these housing developments for just six months. But thanks to strong resident support for their presence, the city kept them there for three additional years.
Chalfin and his colleagues studied the impact of the lights, looking at the impact of crime in those first six months and then over the years.
What they found is that there was around a 36% decrease in nighttime index crimes (in these areas, the most common index crimes were robbery and aggravated assault) thanks to the addition of the lights during the first six months of the intervention, and the effects persisted for the following three years.
Another thing they found is that this decrease in crime did not occur alongside an increase in arrests.
“Crime went down … that’s a good thing. But we’re not seeing evidence that arrests go up. So it seems like what the lights are doing is not reducing crime merely through incapacitation and widening the net of the justice system,” Chalfin said.
His team also discovered a smaller but notable reduction in crime during the daytime in the same locations.
“What I take from that is that it’s not just about lighting. There is some kind of demonstration and signaling effect here that you’re letting people know this is an area that’s being watched. This is an area that’s being cared for,” he said. Additionally, they monitored communities around the public housing developments and did not find that crime was being displaced to other locations.
This doesn’t mean that the street lights intervention can reduce all types of crime, however.
“Most violent crime happens either during the day or inside people’s homes. Like domestic violence is usually the biggest contributor of violent crime in public housing communities and many poor communities, so this isn’t going to have an effect on all types of crime,” Chalfin cautioned.
He also noted that this particular strategy was in place during 2016 through 2019. It’s unclear whether this approach would work following the post-2020 crime surge.