Professor David Newquist has a post on his Northern Valley Beacon Blog concerning statistics about prison populations and state spending on the same here in the Dakotas and nationally. It is worth reading.
Since Professor Newquist has frequently taken me to the woodshed when I misread a source, I feel obliged to return the favor. I note that he badly distorts an important statistic in such a way as to bias the stats in favor of his argument. He says this:
A report by the Pew Center on the States shows that one out every hundred people in the U.S. is in prison, with the total number of people behind bars exceeding 2 million.
Professor Newquist isn't a mathematician, and neither am I, but that is obviously wrong. There are about 303 million people in the United States, so the prison population would have to exceed three million for one out of every hundred people in the U.S. to be in prison.
I managed to track down the Pew Center report that Professor Newquist's numbers seem to come from. Here, I think, is the passage my esteemed colleague gets wrong:
Three decades of growth in America's prison population has quietly nudged the nation across a sobering threshold: for the first time, more than one in every 100 adults is now confined in an American jail or prison.
There's a big difference between one in every 100 people, and one in every 100 adults. Now I suppose that one could accuse my colleague of being a bit careless here. The distortion does make the prison population look even bigger than it really is, and it's very big. But it also invites someone like me to expose it, so I am certain that it was not an intentional distortion. Professor Newquist likes to point out that bloggers aren't real journalists. We don't have fact checkers who work on our pieces independently. Our readers should be at least a little forgiving. I note that, like my colleague, I am more prone to make mistakes when the outcome is convenient.
But real journalists and professional research sources like the Pew Center on the States are also subject to bias, and I think we have a case of that here. Why use adults as the standard, instead of the more usual comparison for the whole population? Granted, we don't send children to prison in the U.S. But prison populations for most countries are measured against total population, if only because the latter statistic is more likely to be available.
Thus, when the Pew Center report compares U.S. statistic with other nations, it has to return to the more standard measurement. Consider this passage:
In Germany, 93 people are in prison for every 100,000 adults and children. In the U.S, the rate is roughly eight times that, or 750 per 100,000 [my italics].
That gives you a comparison that tells you something important: that the proportion of the U.S. population in prison is almost ten times that in Germany. But 750 per 100,000 doesn't give you that "sobering threshold" of 1 in 100. The Pew people are fishing for headlines, and they are intentionally manipulating the stats for bate.
That doesn't mean their results are untrustworthy. They give you the real stat in a chart near the end. About 1 in 133 people is incarcerated in prison or jail in the U.S. (2007 stats, I believe). More interesting are the stats for subpopulations. Here are some real shockers, but they are not the ones that the report highlights.
Let me see if I can get this right: one June 30th, 2006, 1 in every 53 White males, ages 30-34, were behind bars. That compares with 1 in 148 White guys between 45 and 54, and 1 in 588 for ages 55 and older. Why the difference? Well, guess who commits almost all of the serious crimes? It's males, between the ages of 20 and 35.
The really dramatic figures are for Black males between the ages of 20 and 34. One in nine is locked up. One in nine. That is astounding. What explains it? The age and sex statistics tell the story. The vast majority of violent crimes are committed by males in the 20-35 age range. Not females. Not older or younger persons. The incarceration rates in the U.S. may be due to an excessive fondness for prison time, but they accurately reflect the rate at which different subpopulations are committing crimes.
Far more Black males commit serious crimes than Hispanic males. The latter rate is higher than that of White males. Maybe prejudice and social injustice explains all of this. But this is the fact that we ought to be paying attention to. The Pew Center report buried it in the appendix.
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