Violent Crime Wave: Is It The Heat? Is It A Wave?
The murder rate is up and there was a spate of shootings over the weekend. What's behind the increase in violence?
By Jarrett Murphy
Wednesday, Aug 11, 2010
Reacting to the weekend's violence, Mayor Bloomberg called for a tighter crackdown on illegal guns.
As of the first of August, 44 more people were murdered in 2010 than were killed in the city by that point in 2009.
Over the weekend, at least 20 people were shot in the five boroughs, including those hit at the Harlem block party that left cops and civilians wounded and one man dead.
More Criminal JusticeMayor Bloomberg responded to that shooting by saying, "How much longer are we going as a nation to wait before we get serious about stopping illegal guns from getting into the hands of people who mean to do others harm?"
Indeed, guns kill people, because people with guns kill people. But just a few months ago the administration was pointing to indicators--like the number of "crime guns" seized in the city--that suggest the police are having more success at keeping illegal guns out. Illegal guns are still here, but that's not new.
The increase in the city's murder count has actually slowed during the summer. And many parts of the city are seeing not rising but falling numbers of killings. But the uptick is undeniable. So, what's behind this year's crime surge besides the mere availability of guns?
Potential explanations abound. There are fewer cops on the street (about 8,000 fewer than in 2000). There's the economy: The city has boasted of having broken the link between economic stagnation and crime, and the recession was shorter for New York than for the rest of the country, but some neighborhoods are still suffering.
Then there's the heat.
The summer of 2010 is hotter than average, and there is substantial research linking heat to increased violence. Craig A. Anderson, a psychology professor at Iowa State University and one of the foremost experts on the subject, has written that, "There are about 2.6 percent more murders and assults in the United States during the summer than other seasons of the year; hot summers produce a bigger increase in violence than cooler summers; and violence rates are higher in hotter years than in cooler years."
The homicide database created by The New York Times indicates that from 2003 to 2009, 10 percent of all killings in the city took place in July, a greater share than any other month. January, February and March each accounted for only 7 percent of murders. Research out of Kent State University suggests the heat effect is greatest in the midday and early evening hours.
Of course, heat isn't the only thing that makes summer different from other times of year. People change their routines--kids are out of school, and everyone spends more time outside, so folks live in less structured environments where strangers and enemies are more likely to meet and hurt each other.
Anderson's research finds that even when you control for changes in routine, the summer sees more violent crime (some studies say property crime also increases).
But crime doesn't necessarily keep rising as temperatures rise. There's evidence that once temperatures hit a certain point, crime starts to decline. In crude terms, it gets too hot to commit crimes--or at least to stay out doors where some crimes are more likely to occur. This is called "negative affect escape," and there's a lot of debate about whether it actually occurs.
However, while everyone in New York City is feeling the heat this summer, not every area is feeling the crime wave (measured by murders, which are the least common but most accurately measured crime).
As of August 1, 35 of the city's 76 precincts had seen an increase in homicide. The largest percentage increases were in the 114th precinct in Astoria and the 25th in East Harlem; both have seven murders so far this year, a 600 percent rise over 2009. But the more alarming increases are in the 75th precinct, which covers East New York and has suffered 20 slayings so far compared to 12 by this time last year, and the 47th precinct in the Yankee Stadium area, with 16 killings versus nine in 2009.
Meanwhile, 27 precincts have seen a decrease and 14 have the same number of murders as at this time last year. Some of the decreases are substantial: Flatbush's 71st precinct, for one, had eight murders through August 1, 2009 and had only two by the start of August this year.
As of August 1, 13 of the city's precincts had reported no murders in 2010; only 11 precincts could claim that distinction at this time last summer.
The variations from precinct to precinct contribute to a citywide murder level that, while higher than last year's, isn't rising as fast now as it did this winter. Through March 26, New York City's murder count was 22 percent higher in 2010 than in 2009. Now it's only 17 percent higher.