Thursday, March 22, 2012

Chicago Thoughts: Chicago Police Manpower

New York City had a huge crime reduction in the 90s, in no small part due to its professional and large police force. Today, for Chicago's police to have coverage like New York's (at least, based on population density), the CPD would need roughly 15,800 officers. That's 3,500 more officers than Chicago currently has, and 3,500 more officers than we can currently afford. 

Chicago has a crime problem. Every news outlet from Los Angeles to New York knows it. Chicagoans definitely know it, even if they can't identify parties involved, specific neighborhoods, or reasons why. One of the factors in this crime puzzle is police manpower, specifically number of sworn officers on active duty. As New York City hotspot policing strategies showed, more officers did equal less crime. Other factors were involved, but a big part of it was sheer number of police. Today, we are going to look at police manpower for both of these cities today. New York City, a huge town with a comparatively small violent crime rate. Chicago, a smaller town with an embarrassing violent crime rate.

But before we do that, let's just get something out of the way. I love numbers, data, and statistics. My high school transcript might not reflect that, but it is no less true. A lot of these posts are going to talk about numbers and my interpretation of those numbers. In that regard, statistical analysis is just like writing; you spin them to make a point. All of my posts that contain numbers are going to try and make a point. Biased? Opinionated? Yes to both.

So let's get started. 

# Sworn Officers City Population Officers per capita (per 100,000)
New York City 36000 8175133
Chicago 12244 2695598 ~454

By the population metric, Chicago and NYC are pretty close. Chicago has a few more officers per capita than does New York. Based on this alone, it doesn't look like Chicago has a manpower problem. But there are other ways to look at this. Here is one that does not just shock and alarm. It is downright outrageous. Jaw-dropping, in fact.

# Sworn Officers Square Land Mileage Officers per square mile
New York City 36000 302.64
Chicago 12244 227.2 ~54

That's what we call a manpower disaster. NYC has more than DOUBLE the number of officers per square mile than does Chicago. NYC can use this manpower to increase coverage, decrease response times, and generally increase presence. Chicago is on a shoestring police force right now.
In fact, in order for Chicago to have the same number of officers per square mile as NYC, we would need to have a whopping 27,000 officers on our force. If we doubled our current department, we still just wouldn't make it to NYC levels of coverage.

I admit, though, that this is a bit alarmist, not just alarming. After all, square mileage of a city might not be the best way to measure a police force's manpower. Sprawling cities might not have a lot of population. So let's look at a different number, a much more important number, to show the real difference between Chicago and NYC officer strength.

# Sworn Officers Pop. Density/Sq. Mile Ratio of Officers to Density
New York City 36000 27012.5
Chicago 12244 11864.4 ~1.03

First of all, this idea of "Ratio of Officers to Density" is a little abstruse. In fact, it's downright sloppy data analysis, but it gets the message across in this brief space. It lets us extrapolate some idea about police coverage in a city. A NYC square mile has 27000 residents. The police force has roughly 1.3 times as many officers as does any square mile. In Chicago, the police force only has roughly the same number of officers as does any square mile.

Here's where it gets interesting. Let's assume that NYC has optimal coverage of its city, with a good number of police officers relative to its density. Suppose that Chicago wanted to have comparable coverage. Guess how many officers it would need so that it too had a 1.33 coverage ratio, just like NYC?

For the CPD to have coverage like the NYPD (at least, based on population density), it would need roughly 15,800 officers. That's 3,500 more officers than Chicago currently has.

Of course, density may not be the best measure of police coverage. There are a lot of other nuanced metrics we can use. But it gives some sense of the tremendous manpower problem facing the courageous police of Chicago. As anyone who has read the news knows, Illinois is a remarkably broke state, the second most broke after California. There is no money to hire new officers, and even if some room in the budget were made, a mere 100-300 new recruits would not even come close to filling the quota. This leaves the city with a lack of law enforcement and a lack of personnel to stop crime. Bad news for our crime rates, and tough news for the overworked, underappreciated CPD.

1 comment :

  1. I love it! Good, solid data! :) But yikes, what a disaster.