Wednesday, November 7, 2007

Wednesday Math, Vol. 4: The numbers for violent death

As you might recall from a few weeks back, to compare death statistics, the scale is per 100,000 population. We pay a lot of attention to violent death, most especially murder, but the numbers of people who meet their end violently is dwarfed by the numbers for disease. We will be looking at car crashes, murder and suicide. All these numbers combined barely add up to 30 deaths per 100,000 population in a year. Both cancer and heart disease are at around 200 deaths per 100,000 per year. Even if we just restrict ourselves to cancer caused deaths of people less than 65 years old, that accounts for more people dying per year than all the car crashes, murders and suicides combined.

Of all different kinds of violent death, the most common are deaths in car crashes. Every year about 13 to 14 per 100,000 people die in car crashes. Car insurers keep close records of how much of a factor alcohol or driving distracted or mechanical failure or any of a number of other factors change the odds of being in a major accident, but simply stated, we spend a remarkable amount of lives in big pieces of metal moving very fast.

Physics is a bitch.

At the bottom of the list of the three main ways to meet a violent death is murder. In 2001, the national murder rate was 5.7 per 100,000. This means there are about two and a half car crash deaths for every murder. Murder stats are kept more meticulously than the stats for our other two categories. It's easy to find state numbers and region numbers for car crashes and suicides online, but for murder, it's also easy to find numbers per city. The worst state for murder is Louisiana, at 12.4 per 100,000, which is still lower than the car crash death rate for that state. The worst city in 2001 was Compton, California, where the murder rate was 68 per 100,000.

If you watch the detective shows on TV, you might think that most murderers are clever people who can afford the best lawyers. If you watch Nancy Grace, you might think most victims are cute blonde girls. What the numbers in general say is that wherever the drug trade is the best way to make a lot more money than any other options, there are a lot of murders.

The last category I discuss today is suicide. The pictures here are of Ernest Hemingway and Sylvia Plath, two famous people who committed suicide. I give the topic last position because it is the one we think about least, and there are ways to split the numbers up that show remarkable differences by category.

The suicide rate in 2001 was 10.8 per 100,000 population, nearly twice the murder rate. When measured by state, states with low population density tend to have higher suicide rates. In states like Alaska, Wyoming and Nevada, the rates climb to about 17 per 100,000, higher than the rates for car crashes.

Some might make it into a red state-blue state thing. I wouldn't agree. Sartre said "Hell is other people." The numbers say, "Other people may be annoying as hell on the whole, but they do their bit in keeping us from killing ourselves."

The male-female split nationwide is even more remarkable. For men, the suicide rate is 17.6 per 100,000, higher than car crashes. For women, it's 4.1 per 100,000 lower than the murder rate. A surprising number, though exact numbers aren't kept, is that females attempt suicide about three times more often than men, and the total number of suicide attempt in the year in question was around 800,000. This means women who attempted suicide were successful about 1.1% of the time and men were successful about 12% of the time.

I chose the pictures of Hemingway and Plath for a reason. Men are much more likely to use guns to commit suicide than women are. This accounts for the higher success rate, though it is nothing to be proud of. (Hemingway shot himself. Plath turned on the oven and extinguished the pilot light.) Given that nearly 60% of male suicides are done with guns when only about a third of American households own guns means that a gun in the home increases the chance of a successful suicide attempt by a man by a factor of at least 3 and probably 4.

Suicide rates do increase generally as people get older. Once a person hits puberty, the suicide rate climbs above the murder rate and steadily increases as people get older. Here are the rates for the demographic breakdown in the year in question.

age group suicide rate
5-14 0.7
15-24 9.9
25-34 12.8
35-44 14.7
45-54 15.2
55-64 13.1
65-74 13.3
75-84 17.4
85-.. 17.5
Total 10.8

I bring these numbers up, as depressing as they are, in the spirit of informing people about the scale of the risks we face. I have at least one more installment of Wednesday Math that will involve death statistics, and it will be even more emotionally difficult, at least for me, than writing about war or murder or suicide.

Stay tuned, and thanks for your indulgence.

1 comment:

dguzman said...

Great application of math, sir. You really got me with the suicide stuff. I had a colleague and friend who used his gun that way, and it affects me to this day. I absolutely hate hate hate guns in the home, and I've pissed off more than one stupid repub by saying so.