As the mayor of New York City, Rudy Giuliani was a proponent of a controversial policing philosophy known as "broken windows." It calls for police to go after small crimes, in hopes of preventing bigger problems.
At first, it appeared as if violent crime dropped in the neighborhoods where "broken windows" policing was in force. The statistics, however, told a different story.
But the idea remains popular, despite evidence it likely had only modest effects.
KELLY MCEVERS, HOST:
President-elect Donald Trump has floated Rudy Giuliani, the former mayor of New York, as a possible cabinet pick. Giuliani is best known for using a tactic known as broken windows to police New York City in the 1990s, which basically means going after petty crimes in the hopes of preventing bigger ones. NPR's social science correspondent, Shankar Vedantam, looked at where the broken windows theory comes from and how it has evolved.
SHANKAR VEDANTAM, BYLINE: Our story begins in 1969. The psychologist Philip Zimbardo abandoned two cars on the street, one in a crime-ridden section of the Bronx, the other in affluent Palo Alto, Calif. Both cars were left without license plates, parked with the hoods up. Within 10 minutes of leaving the car in the Bronx, people quickly began to strip it for parts. Windows were smashed. But for more than a week in Palo Alto, the other car remained untouched until...
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GEORGE L KELLING: Zimbardo himself gave the car a smash with a sledgehammer. And once the car was damaged, it became fair game.
VEDANTAM: This is George L. Kelling.
KELLING: In 1982, I co-authored an article called "Broken Windows" with James Q. Wilson. This article has gotten considerable attention in the policing and non-policing world.
VEDANTAM: Kelling and Wilson were fascinated by what had happened in Palo Alto.
KELLING: The idea that once disorder begins, it doesn't matter what the neighborhood is. Things can begin to get out of control.
VEDANTAM: Was it possible, they asked, that if police could address minor acts of disorder, more serious crime could be prevented?
KELLING: Communities get strengthened once order is restored or maintained. And it is that dynamic that helps to prevent crime.
VEDANTAM: Kelling and Wilson's argument came during a period of high crime and high incarceration. It appealed to people on both sides of the political spectrum. In 1990s New York, Mayor Rudy Giuliani and his police commissioner, William Bratton, embraced the idea. They went after low-level offenses like smoking marijuana in public, spraying graffiti, selling loose cigarettes. And their strategy seemed to work. By the time Giuliani left office in 2001, broken windows policing had become one of his greatest accomplishments.
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RUDY GIULIANI: The broken windows theory replaced the idea that we were too busy to pay attention to street-level prostitution, too busy to pay attention to panhandling, too busy to pay attention to graffiti. Well, you can't be too busy to pay attention to those things because those are the things that underlie the problems of crime that you have in your society.
VEDANTAM: Kelling conducted an influential study that showed that in the very neighborhoods where police made the most misdemeanor arrests, meaning broken windows policing was in force, violent crime dropped sharply.
KELLING: Once you begin to deal with the small problems in neighborhoods, you begin to empower those neighborhoods.
VEDANTAM: It seemed like a miracle. But the crime statistics tell a different story.
BERNARD HARCOURT: Crime was starting to go down in New York prior to the Giuliani election and prior to the implementation of broken windows policing.
VEDANTAM: Bernard Harcourt is a law professor at Columbia University. He says crime dropped not just in New York, but nationwide, in cities where nothing like broken windows policing was in place.
HARCOURT: Los Angeles was wracked with terrible policing problems during the whole time. In fact, the period is kind of bookended on one side by the Rodney King scandal and on the other side by the Rampart scandal. In between the two, the LAPD is pretty much dysfunctional. And despite the fact that the LAPD isn't doing anything basically - I mean, it's - and it's certainly not doing broken windows policing - crime drops as much in Los Angeles as it does in New York.
VEDANTAM: In 2006, Harcourt reviewed the Kelling study that had found broken windows policing worked. He discovered that it had failed to account for a fundamental principle known as reversion to the mean, the idea that if something goes up a lot, it tends to go down a lot. Crime did decline dramatically in the 1990s, but it also spiked dramatically in the 1980s. And the dramatic decline in crime was accompanied by an increase in something else.
HARCOURT: We immediately saw a sharp increase in complaints of police misconduct. And that's actually one of the most interesting things about the period really from 1993 to '96, for instance, when Giuliani is implementing the quality of life initiative. I mean, we always associate it with greater order because crime dropped 60 percent, but complaints of police misconduct increased by 60 percent.
VEDANTAM: But the metaphor of broken windows proved so compelling that many areas of the country simply ignored the evidence. The idea morphed into new forms. In 2002, the New York Police Department moved from broken windows to a policy of stop and frisk. The idea was why wait for minor disorder to break out? Why not check on seemingly suspicious people before they did anything wrong?
JAMAL JOHNSON: It was, I think, a Wednesday or Thursday night.
VEDANTAM: This is Jamal Johnson. He's African-American, a filmmaker who lives in Brooklyn. Two years ago, he was rounding the corner to his house after an evening out with a friend. A police officer stopped him, frisked him, took down his name and threatened to arrest him because he was carrying a small pocket knife that he uses on film sets. Johnson describes the experience as worse than humiliating.
JOHNSON: When your society can detain you, your life - or at the very least, like, your livelihood, like, you getting to and from work - is at question. So that feeling of an impersonal, not friendly government standing over you is pretty terrible.
VEDANTAM: New York City's stop and frisk policy was ruled unconstitutional in 2013. So what did city officials do? They returned to familiar ground, broken windows policing. Now, more than three decades after writing the article that introduced broken windows to the world, George Kelling says he still believes the policy has value even if it didn't have dramatic effects on crime. But he's dismayed that many police departments think that broken windows can be a quick fix.
KELLING: It's to the point now where I wonder if we should back away from the metaphor of broken windows. Broken windows was a powerful metaphor. Jim and I used it. We didn't know how powerful it was going to be. It simplified. It was easy to communicate. A lot of people got it as a result of the metaphor. It was attractive. And it carried us for a long time. But as you know, metaphors can wear out and become stale.
VEDANTAM: Broken windows is that rare example of an idea that left the academy and caught on like wildfire. It remains popular despite evidence it likely had only modest effects on crime. It's a cautionary tale for our times - once a seductive idea takes hold, it's often impossible to get rid of it. Shankar Vedantam, NPR News.
MCEVERS: Shankar is the host of NPR's Hidden Brain podcast. Transcript provided by NPR, Copyright NPR.