PERFerted Crime Statistics

A report from the Police Executive Research Forum recently prompted alarming newspaper stories about a nationwide surge in violent crime. At FoxNews.com, John Lott picks apart the group's abuse of crime statistics in the service of bigger police budgets:

The Police Executive Research Forum report sounded the alarm: "The FBI statistics reflect the largest single-year percent increase in violent crime in 14 years."

It becomes a lot less scary when one realizes that the violent crime rate fell for 13 straight years, a total drop of 39 percent, before increasing in 2005 by less than 1 percent.

Murder rates did rise from 5.5 per 100,000 people in 2004 to 5.6 in 2005, but they were a little higher a couple of years earlier—5.7 in 2003—and 5.6 in 2001 and 2002.

Murder rates have essentially remained unchanged since 2000 after falling from a peak of 9.8 in 1991.

Lott also reports that PERF emphasized absolute crime numbers instead of rates, "selectively picked what crime categories to report," and used an odd sample of jurisdictions (leaving out obscure places like New York City) that seems designed to exaggerate the increase in homicide.

Comments

[Eryk Boston]

I think the statistical term for this is "dead cat bounce."

[Meyer]

I'll wait until Mary Rosh weighs in.

[de stijl]

Meyer is snide like a shiv.

[bartman]

Nobody deciphers statistical bullshit better than another statistical bullshitter.

[Rex Rhino]

But pool drownings are up! Every year innocent children die because of the reckless activity of recreational swimming!

There are plenty of non-water-based activites that promote good health, there is no constitutional right to swimming! Do you think our forefathers had any idea that would be 6-8 feet deep swiming pools in people's suburban back yards when they wrote the constitution?

You may say swimming is safe - that so few people die in swimming accidents that it doesn't really matter. But accidental drownings are one the top causes of death for children under the age of 12. Tell a parent of a dead drowned baby that "a little water is harmless".

If it wasn't for the chlorine industry and the makers of sunscreen spending billions of dollars to keep their industry of death legal, swimming would have been outlawed a long time ago! It is time we make sure that only Police SCUBA teams and Navy Seals are allowed to swim, and no more children have to die needlessly! Stop the madness!

For you to focus on crime statistics, when children are drowning every day, is an afront to real working Americans. It is time that Reason left its ivory tower, and focused less on crime and more on drownings!

[Jim H]

This just in.

John Lott has been killed in a drug raid. The police were acting on tips from anonymous informants that reported the presence of weapons, drugs and a surveillance system. In order to protect the safety of the officers, the police entered utilizing a so-called "no knock" warrant. Mr. Lott reacted in a violent manner, forcing the officers to act in self defense. He was pronounced dead on the scene.

Radley Balko was unavailable for comment. Local law enforcement refused to comment on rumors that Mr. Balko had been last seen trying to get details on the matter stating that there was an ongoing investigation.

[Leonardo]

Data that has time as an independent variable is often manipulated or misinterpreted. For instance, if a stock goes down 50% one year and up 50% the next year, it is still down 25% but the average return is 0%, which is much better. Also, as happens in the study you cite, one can say that the stock is up 50%, which looks really good, but less good over a longer period.

[joe]

I think you just come out with the Office Approved Reason Magazine Code for Discussing the Recent Rise in Crime Rates.

Because every time anyone on this site blogs about the rising national crime rate, it's written as a criticism of the author's language.

[Kazakhstan National Anthem]

But pool drownings are up! Every year innocent children die because of the reckless activity of recreational swimming!

Kazakhstan home of Tinshein swimming pool.
It's length thirty meter and width six meter.

[bill]

The first thing I was taught in college statistics was "There are lies, damn lies and statistics".