The New York Times has a year-end story on the under-reporting of crime. There's a New York City commission at work studying crime reporting. The Times story shows how when someone notifies the NYPD of a crime, the degree of interest shown by the local police precinct can affect what is actually reported.
Time travelers will be interested in some of the antecedents of this story. The FBI processes local police reporting and sets the framework for recording crimes that are summarized in the Uniform Crime Rates published by the FBI.
Back in 1973, the Council on Municipal Performance published a report comparing crime rates in the 30 largest U.S. cities. I was involved in preparing the report, spent some significant time reading about the contemporary variability of crime reporting in big cities, and prepared a report on what the Council learned from its work.
Eight topics regarding crime reporting dominated the report. Only one related to systematic police under-reporting:
1. Systematic under-reporting was found most likely during election years. The cities of Chicago and Philadelphia were singled out as two big cities with big systematic swings in crime reporting. Police chiefs eager to retain their positions would get the word out to precinct captains that lower crime rates would be helpful to the Mayor and therefore to the police department.
2. Crime rates would systematically rise when police budgets were being reviewed. Under-reporting is only half the picture. When police departments were interested in budget increases, crime rates would rise.
3. Grand larceny was an easy number to skew. Back in 1973, the difference between grand larceny (which was reportable to the FBI for the Uniform Crime Rates) and petty larceny was a matter of estimating how much money was stolen. The cutoff was $50. So all it took to reduce reported crime was to raise or lower the bar for deciding whether someone's purse and contents were worth less or more than $50. An issue for the FBI was that state laws regarding the definition of larceny varied (states where the definition of grand larceny was the stealing of something worth $5 or more did not update their laws).
4. Grand larceny had a built-in inflation bias. The $50 FBI threshold for grand larceny had not been changed for many years, so that reported incidents of grand larceny rose steadily every year. This was fine by J. Edgar Hoover, who would intone each year about the gravity of the ever-growing crime wave. Subsequent to the Council on Municipal Performance raising this crime-incident-inflation issue in the press, the FBI raised the threshold. It is now $250. But how does a police officer recording the incident value the loss of, say, a credit card or a car with 150,000 miles on it? There are legitimate definitional questions that are worthy of the attention of the New York City crime-reporting commission.
5. The hardest number to fudge is homicide. It's not easy to explain away a corpse. The easiest assumptions are accident or suicide, which are not crimes. But except for anonymous homeless people, the police will have relatives following up. So the homicide rate tends to be pretty reliable.
6. Cultural trends influence crime reporting over time. The woman's liberation movement made it much more acceptable for a woman to report being raped. The rise in the number of rapes was most like the result not of an increased incidence of rapes (quite likely the opposite), but of the willingness of women to file reports with the police.
7. Cultural differences affect reporting among cities and neighborhoods. An assault in one part of town might be considered criminal whereas in another it would be considered a crime. Police precincts may vary in how they handle assault complaints. They most likely vary systematically among cities.
8. The best way to ensure uniformity in crime reporting is through internal and external audits. The FBI has its own standards when reviewing city crime reports. In the past it has refused to report city crime numbers that it considered hard to believe or inadequately documented. To ensure credible reports, cities have themselves hired outside auditors to review their crime reporting systems on a precinct-by-precinct basis. Internal auditors should be at work in every big-city police department making sure that the standards for classifying crimes are being uniformly disseminated and applied.