New York City experienced a historic decline in crime rates during the 1990s, but it was not due to the implementation of CompStat or enhanced enforcement of misdemeanor offenses, according to an analysis by New York University sociologist David Greenberg. The study, which appears in the journal Justice Quarterly, did not find a link between arrests on misdemeanor charges and drops in felonies, such as homicides, robberies, and assaults. In addition, the analysis revealed no significant drop in violent or property crime attributable to the NYPD's introduction of CompStat in 1994.
"While the 1990s drop in felonies is undeniable, what remains unsolved is the cause, or causes, behind this significant change in New York City's crime rates," Greenberg said.
The analysis also showed no relationship between the number of police officers per capita at the precinct level and the reduction of violent crime, nor did it find a link between admissions to prison and violent crime rates.
Greenberg looked at crime data across New York City's 75 precincts from 1988 through 2001. During this period, homicide rates declined in every precinct while assault rates dropped in all but two and robbery rates fell in all but one.
"The decline in crime was a real one during this period, but the question is 'Why?' " said Greenberg, adding that many other major cities, including San Diego and Los Angeles, experienced similar reductions during this period.
One of the potential causes he explored was CompStat, a computerized crime-tracking program the NYPD adopted in 1994 to better identify and respond to criminal activity.
The analysis showed that violent crime rates (homicide, aggravated assault, forcible rape, and robbery) and property crime rates did not significantly decrease after the implementation of CompStat—in fact, both continued on a consistent downward slope beginning in the early 1990s.
"There is no indication here that CompStat had any non-trivial effect on violent or property crime rates in New York," Greenberg wrote.
Greenberg also explored the possibility that a greater number of arrests on misdemeanor charges led to drops in felonies. Such a result would offer affirmation of the "Broken Windows Theory," which posits that stricter enforcement of lower-level crimes curtails more serious ones.
The 1988-2001 period showed a consistent decline in crime rates for major felonies, but an uptick in misdemeanors in all but 11 precincts.
However, based on a deeper review of the publicly available statistical data, there appears to be little evidence of causation.
In reaching this conclusion, Greenberg examined nearly two dozen variables at the precinct level (e.g., misdemeanor arrests, poverty rates, percentage of 15-24 year olds, imprisonment rates, size of a precinct's police force) and their association with rates of felonies.
While misdemeanor arrests rose 37 percent across New York City between 1988 and 2001, there was no association between these arrests and felony crime rates at the precinct level. In fact, with the exception of felony arrests contributing modestly to the drop in robberies, the analysis revealed no significant contribution made by law enforcement to the drop in more serious crimes. For example, both the overall size of the police force and city-wide imprisonment rates decreased during this time. Moreover, at the precinct level, rates of arrest and imprisonment varied greatly across New York—and throughout the studied period—while felonies dropped consistently across the city.
"While many may point to greater enforcement of lower-level offenses as a factor in curbing more serious crimes, the data simply don't support this conclusion," Greenberg observed.