Allegations this week that New York City police officers manipulated crime statistics to avoid the appearance of crime increases inevitably raise questions about New York’s widely touted crime decline.
No one doubts that murders, robberies, burglaries, and other serious crimes in New York have fallen since the early 1990s. The question is whether the official crime figures can be trusted to tell us just how much safer the city has become.
That question cannot be answered fully by interviewing retired police officers or reopening closed cases. Even the most scrupulous audits of police records cannot recover unrecorded crimes. And there is no way to count, much less reinvestigate, all the serious crimes that were improperly classified as lesser offenses five or ten years ago.
It would be useful if we had independent and reliable data on crime trends not subject to police manipulation. Fortunately, we do.
Since the early 1970s, the U. S. Justice Department’s Bureau of Justice Statistics has compiled crime data from national surveys of persons age 12 and over. The anonymous National Crime Victimization Survey (NCVS) asks respondents if they were victims of certain types of crime over the past six months and, if so, whether they reported the crime to the police. The surveys are valuable not only for revealing crimes that are not reported to the police but also for validating trends in police-recorded crimes.
Representative NCVS data for residents of the New York metropolitan area, the vast majority of whom live in the five boroughs of New York City, show crime drops since the early 1990s just as large as those derived from the police statistics. For example, the accompanying figure shows New York’s burglary trends based on police statistics and NCVS data between 1980 and 2003. (The survey data are not available for New York for more recent years and have been expressed as three-year moving averages to smooth out year-to-year fluctuations.)
Both the police and the survey data exhibit the same pattern of change over time, including sizable burglary declines since the early 1990s. Moreover, the burglaries that victims say they reported to the police correspond very closely to the number of police-recorded burglaries throughout the 24 year period. We find a similar pattern of results when comparing trends in robberies and aggravated assaults from the victim surveys and police statistics.
The victim surveys cannot settle debates over the reasons behind the crime drop, nor do they relieve the NYPD of the responsibility to thoroughly investigate charges that some officers may have doctored the official crime statistics. Crime victims and the general public must be convinced that the police faithfully record all crimes reported to them.
But the victim surveys provide reassuring evidence that New York’s crime drop is real and not an artifact of police manipulation. And they can offer the same kind of independent evaluation when the crime rates of other large cities are called into question.
Richard Rosenfeld is professor of criminology at the University of Missouri-St. Louis and President of the American Society of Criminology. Janet Lauritsen is professor of criminology at the University of Missouri-St. Louis.