In an op-ed piece in the Star Tribune this week advocating school vouchers, Mitch Pearlstein, founder and executive director of Center of the American Experiment, wrote the following about Myron Orfield's argument that racially segregated urban schools are a bad thing:

"Nevertheless, unless I'm missing something, Orfield dismisses a very large problem when it comes to implementing some kind of remedy. Correct me if I'm wrong, but if significant numbers of minority students were to transfer out of Minneapolis and St. Paul schools, wouldn't significant numbers of white students need to transfer in? Otherwise, public schools in the two central cities would grow even more disproportionately minority."

I appreciate Mitch's invitation to correct him if he's wrong. It shows humility. So:

You're wrong, Mitch. If a significant number of minority students were to transfer out of the city schools, that would lower the numerator (minority students) and the denominator (total students). If you have 10 jelly beans and three are blue, that's 30 percent. Remove one blue jelly bean, and you're down to two blue out of nine, or 22 percent. So the departure of minority students from city school districts (without replacement by white students) actually makes the districts less proportionately minority.

Public Numbers is not taking a position here on school vouchers, which Mitch argues is a way to increase integration. We're just arguing for the proper use of arithmetic. We hope Mitch takes this in the proper spirit and will continue to submit pieces for publication in MinnPost's Community Voices, where we aspire to correct arithmetical errors — if any — prior to publication.

Joel Kramer is editor and CEO of MinnPost.

ADDENDUM: Forty minutes after we posted this item, Mitch e-mailed the response below:

From: Mitch Pearlstein
Date: Fri, 14 Dec 2007 14:50:54
To: Joel Kramer
Cc: Mitch Pearlstein

Joel,

Congratulations, as you're the first person (other than somebody over here at America Experiment) to catch my thoroughly dumb mathematical mistake.

As you can see below, once we discovered it Thursday morning, hours after the piece appeared, I sent a note to various folks pointing out the screw-up and apologizing for it. Evidently, I compounded my original mistake by not including you in the dissemination. Actually, hindsight suggests we should have posted something on the Center's website for all to see, pronto.

Fully serious for a moment, as I trust you know, I embrace the canons of journalism and scholarship with sacred seriousness and have been known to lose sleep after accidently omitting a comma from a quote written by someone dead for decades.

Please feel free to run this note. Better yet, I'd be grateful if you did so.

And thanks for the holiday cheerfulness with which you've reminded me — and alerted several thousand other people — of what started out as a great Thursday but turned really sour by about 10 a.m.

Best,

Mitch

 

From: Mitch Pearlstein
Sent: Thursday, December 13, 2007 3:49 PM
Subject: Please delete one sentence

Friends,

Someone on staff has caught a stupid mistake of mine in the desegregation/voucher column I sent you earlier today (or that you otherwise know about). The last sentence in the second paragraph makes no sense. Actually, it's 180-degrees mathematically wrong.

I do have a half-way plausible excuse, though the most accurate explanation is garden-variety vapor lock. If you do anything with the piece or pass it along, please delete the line that reads: "Otherwise, public schools in the two central cities would grow even more disproportionately minority." The column works perfectly well without it. Infinitely better, actually, and we'll be disseminating it without the dumb sentence, albeit with an "In the interest of full disclosure . . . ." caveat at the bottom.

My apologies and many thanks.

Mitch