Friday, December 30, 2005

Why is Crime Still Falling in New York City?

Major center cities around the United States have experienced a reduction in violent crimes over the last 15 years. There are some blips in the data. In 2003, there were 71 murders in the city of San Francisco while in 2004 there were 88 murders. The article below also notes that the murder count is up in other cities such as Boston and Houston.

Today the New York Times takes a closer look at the recent New York City numbers. Two points stand out in this article. First, the author does try to identify one natural experiment. Post 9/11, the city had a budget crisis and cut back on cops and due to Homeland Security mandates had to reassign police to other tasks away from basic safety.

I'm also surprised that no economists were interviewed for this article. I don't really understand how reporters choose who is an "expert" on any given topic but I wonder why Steve Levitt was not interviewed here. The abortion hypothesis might be relevant here. Another controversial but interesting hypothesis is that the decline of leaded gasoline use in cities is another cause of the crime decline. New York City is the densest city in the United States. The lead theory posits the logic chain that exposure to ambient lead lowers children's IQ and increases the probability that they will have ADD. Low IQ and ADD both predict becoming a criminal in later life.

So, my point is that the New York Times does a fine job of describing basic urban quality of life trends but it often wimps out in attempting to explain why the trends we see have taken place. Given the brain power of the typical Times reader, I'm surprised that this newspaper of record does not invest more resources in exploring causal explanations and helping readers "hypothesis test".


December 31, 2005
Crime Numbers Keep Dropping Across the City
By AL BAKER

Crime has fallen across New York City for the 17th consecutive year, with subway crime down by more than 5 percent from last year and the number of recorded murders virtually certain to be the fewest in any single year since 1963, new Police Department statistics show.

As of yesterday, there had been 537 killings in the city, according to the department's latest marking-period reports that are issued weekly. That is down from 566 in the same period last year. And it is down from 649 in all of 2001, when joblessness surged, anxiety from Sept. 11 was present and a budget crisis prompted a reduction in numbers of city police officers. In that year, some citizens and criminal justice experts predicted a bottoming out of the crime downturn as the police force took on new counterterrorism responsibilities.

New York reported its greatest number of murders in 1990, when 2,245 people lost their lives by violence.

In 2005, in addition to murders, numbers for rape, felony assault, burglary and grand larceny all fell, the department said.

Auto theft, which, like murder, is considered a reliable indicator of crime patterns because there is little discretion in how to classify it and little reluctance in reporting it, fell by nearly 12 percent.

"When you get eight million people together, you will have some crime," said Police Commissioner Raymond W. Kelly. "But is the city improving? And, is quality of life improving? Most believe that and believe that cops are doing a great job and crime is coming down."

New York's continuing decline is in contrast to some other cities across the nation. After years of falling crime, Boston is now experiencing a surge in homicides. Houston has seen more killings in 2005. In Philadelphia, murders are outpacing last year's rate. Some law enforcement officials have attributed rising murder rates outside of New York to use of the drug methamphetamine.

David M. Kennedy, the director of the Center for Crime Prevention and Control at the John Jay College of Criminal Justice in Manhattan, said, "Nobody else, anywhere, has been able to generate either the huge reductions in violent crime or sustain those reductions without reversal for 10 years, which is what New York has now done."

In the view of some critics, the overall numbers seem too good to be true. Officials in the Patrolmen's Benevolent Association, the main police union, charged last year that precinct commanders felt such pressure to drive down crime that they "cook the books," reducing the severity of crimes on paper to avoid recording them and reporting them to the F.B.I.

But the department has an internal auditing system, said Michael J. Farrell, the deputy commissioner for strategic initiatives. Since that system was put in place in the early 1990's, the error rate has gone to 1.5 percent from 4.4 percent, he said.

"The aspect of it that reassures us are the audits that we do, which are very substantial, in terms of the number," Mr. Farrell said. "Every precinct is audited randomly, twice a year."

Of course, on any given day in the city, the streets can feel dangerous.

Arrests for guns are up, heading into the last week of this year. Two police officers have been killed in the line of duty in recent weeks, and more officers were shot this year, 8, the highest number since 1997, when 10 were shot and one was killed. The 2005 murder tally could still increase by midnight tonight or when some 2005 deaths because of unknown causes are finally determined by the medical examiner.

Shootings, a crime statistic the department has tracked for the last 12 years, were up by 3.2 percent, to 1,508 from 1,461. And the number of victims wounded in those shootings rose to 1,808 from 1,755. The shootings, though, were concentrated in a handful of precincts, and they have now started to fall. This year could well wind up with the second-lowest number of shootings since 1993.

The precinct with the greatest number of incidents of gunfire in 2005 was the 75th Precinct, in East New York, Brooklyn, which recorded 92. The most gun arrests, 225, happened there, too.

The citywide dips in five of the major crime categories was followed by roughly proportional dips in arrests for those crimes. But the number of robberies increased, by 0.8 percent, and, consequently, robbery arrests mushroomed to nearly 11 percent as the police focused on the problem.

Or, as Mr. Farrell put it, to "re-inoculate" a new generation of criminals "who may not have gotten that vaccine."

Put in context, the rise in robberies, to 23,948 from 23,746, comes in a category of crime that is a mere shadow of its former self: their number peaked at 100,280 in 1990, said Thomas A. Reppetto, a police historian and executive director of the Citizens Crime Commission, a group that monitors police policies in New York.

In all, the numbers collected, computerized and crunched by the New York Police Department reveal all manner of trends and developments.

In 2005, eight precincts in the city recorded not a single murder - vast parts of the city that included Central Park and the 94th Precinct in Greenpoint, Brooklyn, where there were four murders last year, and in 1990 there were eight.

Five precincts, including one covering the Long Island City section of Queens and another, in the Fordham and Bedford Park sections of the Bronx, recorded some of the highest numbers of violent crimes this year. There were 229 robberies in the 108th Precinct in Queens, for instance. But even with those high numbers, it was those very precincts that recorded the greatest reductions when set against last year. For example, robberies in the 108th were down by 16 percent.

Perception can be as much a measure of crime as reported statistics. In 1963, as today, some sensational cases made headlines for weeks. Then, it was the so-called Career Girl murders, the double homicide of a Newsweek researcher and a teacher on the Upper East Side. There were a total of 548 homicides that year. Now, it is Peter Braunstein, a writer suspected of posing as a firefighter in an Oct. 31 sex assault in Chelsea.

Commissioner Kelly, for his part, said no floor for any crime is acceptable. The department tracks crime in "real time," he said, and maps it down to street corners.

The manpower for Operation Impact, a program started by Mr. Kelly to flood problem areas with Police Academy recruits accompanied by more experienced officers, will be doubled next month to include 1,200 officers. A strategy of splitting the most violent precincts into thirds, Operation Trident, will be put in place in the 44th and 46th Precincts, he said.

Many people, however, including Andrew Karmen, a criminologist who has analyzed the factors affecting the city's crime, have wondered just how long this trend - what Dr. Karmen calls a "crime crash" - can last.

"I think there is room for even further progress because in other large cities around the world, such as London and Tokyo, people get along even better with each other than we do," said Dr. Karmen, who wrote the book, "New York Murder Mystery" (N.Y.U. Press, 2000), about declining crime rates in the 1990's.

Dr. Karmen said that most criminologists attribute New York's falling crime rate to both criminal justice and broader societal factors, including smarter police work, tougher sentencing, improved job opportunities and the perception of an improved economy.

Mr. Kennedy said: "The controversy remains. Is it something that law enforcement did, or isn't it? My thought is, you can't explain it without a very large contribution from law enforcement."

Heading into his second term, Mayor Michael R. Bloomberg said the record bodes well for the future.

"Every year, experts say we can't drive crime down any further, but happily the N.Y.P.D. proves them wrong and breaks another record," Mr. Bloomberg said.

1 comment :

Al Z said...

I understand your point but hypotheses are better left out of this sort of reporting: "just the facts, Ma'am". No matter how carefully the hypotheses are characterized as such, they inevitably get construed as fact.

In contrast to NYC, Toronto is experiencing its "worse" year for homicide since 1991 (88 in 1991, 78 in 2005):

http://www.democratandchronicle.com/apps/pbcs.dll/article?AID=/20051228/NEWS01/512280363&SearchID=73231139569949

But these numbers still pale in comparison to NYC even accounting for differences in size. This reinforces Andrew Karmen's argument, the trend may be real, but the level of violence in NYC then and now is still comparitatively significant.

It's interesting that homicides peaked in many places in the early 90's and some of these places are now seeing a resurgence back to those levels - except for NYC. What is the ruling hypothesis for the 1990 peak?