Saturday, December 15, 2012

Growing problem?

(No poker content.)

In the wake of yesterday's school shooting in Connecticut, I tried discussing possible solutions with various friends and strangers on Twitter--which admittedly is a pretty awful medium for such things. One of them first said that school shootings were an "epidemic." When I questioned the validity of that label, he said he was willing to settle for calling it a "growing and disturbing trend." I asked him for his statistical evidence that it was a "growing" problem. He admitted that he had none other than "being alive for the last 20 years."

I had no specific evidence in mind. I didn't know offhand whether it was a growing, shrinking, or stable problem. I am, however, aware of the very human tendency to feel that things are getting worse even if they are not. Our minds tend to emphasize recent things more than past things, making us not very reliable at judging trends in the absence of actual hard data.

This morning I was reading a piece by Nick Gillespie in Reason magazine's "Hit and Run" blog: "4 Awful Reactions to Sandy Hook School Shootings--And Thoughts on a Better Response." He points to this helpful table of data from the National Center for Education Statistics, citing it for the proposition that our schools are actually getting safer over time, not more dangerous. It's downloadable as an Excel spreadsheet. I had Excel spit out this graph from the table:


The only massaging of the data I have done is to add a five-year moving average, in an attempt to damp down some of the wide year-to-year swings. Each pink dot is the arithmetic mean of the previous five years.

If there is any directionality to the trend line, it is downward. You might say that there is no clear trend in either direction, that the variation from year to year is so great that you can't discern any definite overall movement either up or down. I wouldn't quibble with that reading.

But I don't think any fair-minded person can look at these numbers (I'm taking for granted that they are complete and accurate) and say that homicides of school children are a "growing" phenomenon, or any more of an "epidemic" than was the case 20 years ago. Moreover, this table from the same organization shows that total school enrollment (pre-kindergarten to grade 12) has increased from 46,864,000 in 1990 to 54,704,000 in 2010, a growth of about 17%. This means that even if the absolute number of school homicide deaths were steady over time, the risk per student is declining.

Of course, this conclusion does not mean that each death is not tragic, or that we should just shrug our shoulders and live with things as they are. But I firmly believe that public policy debates have to be grounded in objective facts, or they are bound to go off in the wrong direction.

I am proposing no particular solutions here. I just wanted to present the data as a starting point for figuring out what more, if anything, can and should be done about the problem.


8 comments:

nottom said...

I also read the Reason article you linked and after looking at the charts in the article and reading his assessment, it seems to me that while we are safer overall there does seem to be a rise in this sort of mass violence which is obviously the kind of stuff people tend to remember.

itchyskippy said...

As a teacher I dread Monday and the overreaction from the district. On Friday we got a flash saying to not discuss it, which I could understand. What with a lack of information and all.

At the end of the day we were told most likely we would have to keep our doors locked and that is just plain sad. We already have no windows and often we prop doors open for fresh air and to enjoy the weather. Plus what a pain to have to stop and open doors several times a day for students going here and there. (although that will probably change also)

So sad, school is one place we strive to make sure the kids feel safe and secure as often it is the only place they get that.

Anonymous said...

Whatever you need to tell yourself so you can sleep at night, you gun freak.

CoolDave88 said...

Who is a gun freak? Why do you post anonymously? Grump posts data and thoughtful commentary on a problem many of us are struggling to comprehend and find a correct balance. Give people a break. Knee-jerk reactions are not going to solve this problem. Banning guns will not do it although I'm not sure we need assault rifles. A well informed, spirited and respectful debate is sorely needed on this and most other issues of the day.

Glenn from Minnesota said...

It isn't just the schools, but the malls, the movies and all the other public places where large groups of people congregate. If you think that this problem is not escalating, you truly have your head in the sand. We don't need assault weapons or handguns for that matter. Even in the wild west, they attempted to disarm the crazies when they were within the city limits. We need change to the gun laws!

Anonymous said...

I sign in as Anonymous because I do not have a Google account or URL. This is a topic on which everyone has a very strong opinion and whatever I say will not change your mind or Grump’s. But how anyone can write such a blithe posting (with a graph, nonetheless!) when there are TWENTY DEAD FIRST GRADERS out there is beyond me

Rakewell said...

Glenn: Please read this and the articles linked within in, then tell me if you still say the problem is escalating--and, if so, on what database you rely for that conclusion.

http://goo.gl/z7owF

Anonymous said...

This guy put between 3 and 11 bullets in each victim, killing 26 in less than 5 minutes. He showed every intention of continuing and with the ammo he still had he could have killed over 100 children. He only stopped because the police arrived. While school shootings may or not be increasing is the question you pose I think we should be considering the horrific scenarios possible because we allow our citizens to arm themselves with assault weapons and unlimited ammunition. If this unspeakable event doesn't move you what will? When we started allowing ordinary citizens to possess weapons of mass destruction we set the stage to events like this. If we don't do something quickly the day will come when this body count will look like child's play