After September 11, as New Yorks Finest turned some of their attention away from ordinary policing and focused on preventing another terrorist strike, violent crime spiked up in some areas of the city. The spike suggested how activist policing really does cut crime: if you stop doing it, this is what happens. The experience served as a reminder that Gothams amazing crime turnaround during the 1990s, with murder falling 70 percent and violent crimes in general down by more than half, rested on the innovations of Giuliani-era policingand above all on the broken-windows strategy of policing such quality of life offenses as aggressive panhandling and public urination, on the assumption that tolerating such disorder gives wrongdoers the impression that no one is in charge and encourages more serious offenses.
Most academic criminologists, however, dont buy the idea that changes in policing can change the crime rate. They believe that root causes or vast impersonal forcesnot policy choicesexplain changes in the crime rate. According to these academics, crime declined in the nineties because the crack epidemic burned itself out; the economy boomed, so poor people werent forced into a life of crime; and there were fewer testosterone-charged, crime-prone young males around. And if policing did contribute a little to lowering crime, in the ivory-tower view, the costs were excessive, as activist cops spread a reign of terror in poor minority neighborhoods.
To test these views, in 1999, under the auspices of the Manhattan Institute, we decided to collect and analyze data to see what really did cause crime to fall so dramatically in the city. We collected precinct-level data on violent crime and misdemeanors, and data on some of the vast forces criminologists credit with the crime drop: drug-use patterns, school enrollment, unemployment. Then we examined the relationships.
The results strongly indicated that broken-windows policing does matter in cutting crimea lot. None of the other leading explanations seems plausible. Broken-windows policing significantly and strongly associates with sharp reductions in violent crime; in fact, we estimate that it prevented at least 60,000 violent crimes in New York between 1989 and 1998. By contrast, changes in the number of high schoolage males bore no significant association with changes in the amount of violent crime. Nor did shifts in drug use. As for the economy, changes in unemployment levels did relate weakly to reduced violent crimebut in exactly the opposite way than criminologists had theorized. Over the ten-year period of our analysis, violent crime actually dipped as unemployment worsened. Our findings leave all the conventional explanations with little to support them.
In addition, we did what criminologists usually dont do: we went and looked for ourselves, firsthand, spending time at six precincts. We sat in on strategy meetings, interviewed officers, and observed them as they went about their work. Contrary to the critics charge that the NYPD is a mindless, oppressive force, what we discovered is that officers who enforced broken-windows laws routinely evaluated the actual situation at hand and the potential consequences of their actions. While arresting a minor offender was always an option, for example, police used discretion and often warned the offender verbally instead.
Precinct leaders, we also learned from our up-close observations, regularly used the now-famous Compstat system of computerized crime tracking and establishing accountabilityanother Giuliani-Bratton innovationto identify potential crime problems and come up with smart ways to deal with them before they materialized. Though we dont have data that prove Compstat has helped slash New Yorks crime rate, everything that we saw suggests that it has. We noted that commanders successfully called their shots: when Compstat focused their attention on fighting a given category of crime, that kind of crime usually decreased.
No matter what happens in the future to the root causes and vast forces, theres no reason to fear that the NYPD, if it builds on its current strengths, will be unable to keep crime under control.