It’s not the things you don’t know that hurt you, it’s the things you know for sure that just ain’t so. — Anonymous

I was surfing the web the other day and came across a post on Prof. Berman’s Sentencing Law & Policy blog, citing another pair of newspaper articles bemoaning the mass incarceration that has taken place in this country.  I say “another” because it’s hard to go a week without finding some story pointing out that America now leads the world in rate of imprisonment of its citizens.  I’ve contributed my own noise to this din, as typified by this piece a year and a half ago.  In fact, it’s become the accepted conventional wisdom that

• We imprison too many people
• We imprison them for too long
• Many of them are non-violent offenders who pose little threat to society
• Minorities, and especially blacks, suffer disproportionately, usually because of drug laws that are especially punitive toward them (e.g., the powder/crack disparity)

So I was a little taken aback by a George Will column I came across a few weeks ago, which basically rejected all those claims.  The increase in our prison population is due almost solely to an increase in violent offenders being sent to prison with greater frequency and for longer durations.  Absent recidivism, the chance of a non-violent offender being sent to prison is exceedingly low.  And the reason blacks are sent to prison in disproportionate numbers is because they commit a disproportionate number of crimes.

These aren’t Will’s opinions, they’re the product of research by Heather MacDonald, a fellow at the Manhattan Institute, a right-wing think tank; the article which serves as the basis for Will’s piece was published in the Institute’s City Journal, and can be found here.  As Ms. MacDonald’s ouevre indicates, she’s hardly an impartial source; article titles like “Remove Cuffs on the LAPD,” “NYPD:  Heroes in the Dark,” and “What’s behind stop &frisks?  High black crime,” she basically gives the game away.  That doesn’t mean she’s wrong, though:  even a writer for the ideologically opposite Mother Jones, while at one point denouncing her as “the thinking bigot’s Ann Coulter, grudgingly concedes in another piece that MacDonald’s “City Journal latest is a devastating response to the liberal shibboleth that the criminal justice system is racist and designed to criminalize and incarcerate blacks en masse.”

It doesn’t mean that MacDonald is necessarily right, either.  There’s a number of ways that you can play around with statistics, and as any good lawyer knows, if you adopt a particular perspective, it’s not hard to come up with the evidence to prove that view.  There’s other evidence, including some studies that I cited in my post last year, that contradict, at least in part, some of MacDonald’s assertions.

But that evidence may be no better than MacDonald’s, because it may come from no less partial an observer.   The degree to which flawed data can become accepted wisdom is demonstrated in another piece by MacDonald, one she wrote on the “campus rape crisis.”  She eviscerates the central claim of campus sexual-assault organizations — that 25% of college coeds will be the victims of rape or attempted rape — noting

If the one-in-four statistic is correct, campus rape represents a crime wave of unprecedented proportions. No felony, much less one as serious as rape, has a victimization rate remotely approaching 20% or 25%, even over many years. The 2006 violent crime rate in Detroit, one of the most violent cities in the U.S., was 2,400 murders, rapes, robberies, and aggravated assaults per 100,000 inhabitants — a rate of 2.4%.

One of the major issues facing this country is crime and punishment, and that’s largely intertwined with race.  The main point here might be that instead of an intelligent discussion of the subject based upon objective evidence, we are faced with impassioned advocates, each with an ideological axe to grind, each presenting flawed data in an attempt to vindicate their view.  A little skepticism of all claims might be in order.