Statistical Illiteracy, or How Eating Ice Cream Causes Sunstroke

Dan Domenech is a highly educated man. The Executive Director of the American Association of School Administrators, Dr. Domenech was once Superintendent of the Fairfax County (Va.) Public schools (168,000 students) and holds a Ph.D from Hofstra University.

Domenech is also statistically illiterate. That’s a shame for one whose mission is to help school administrators advance the goals of public education and advocate for the children.

Statistical illiteracy is shockingly common in our society. As one wag observed, 8 out of 5 people suffer from it. More seriously, Gerd Gigerenzer, an eminent German psychologist, recently wrote that “Statistical literacy is a necessary precondition for an educated citizenship in a technological democracy.” He is absolutely correct. It is vital that voters, politicians, bureaucrats, journalists, health professionals, and all manner of businesspeople understand the numbers behind policy decisions that we must make.

What was Domenech’s statistical faux pas? In a recent interview with National Public Radio, Domenech weighed in on the case of an Ohio mother who sent her kids to another school district for a better education. She was found out, tried, convicted, and imprisoned (briefly) for lying about her residency. Domenech, decrying the disparity in education quality between districts, said: "The correlation between student achievement and zip code is 100 percent. The quality of education you receive is entirely predictable based on where you live."

First let’s review a brief definition of correlation. When two measurements tend to move together, they are said to be correlated. For instance, if you were to prepare a table of daily ice cream cone sales and daily high temperature, you would see that more ice cream is consumed at 90 degrees than at 30. Ice cream sales and temperature are said to be correlated. Similarly, a comparison of sunstroke incidents to temperature would show a kindred relationship. But one must be careful – correlation does not imply causation. If you looked only at sunstroke rates and ice cream cone sales, they would also be correlated, that is, high sunstroke rates occur with high ice cream sales and vice versa. But one cannot say that eating ice cream causes sunstroke. Behind the scenes, they are both correlated with a common variable – the temperature.

Correlation is represented by a number between zero and one that describes the degree of relationship between the two variables. A correlation of zero means that variables are completely unrelated, such as the cost of bubblegum and the distance between star clusters. A correlation of one, on the other hand, means that the variables are perfectly related, such as the number of pennies represented by various dollar amounts.

A discussion of direct vs. inverse and negative correlation will be postponed to a future topic.

So let’s return to Dr. Domenech. If the correlation between student achievement and zip code were indeed 100%, then all of the students in a given zip code must have the same grade. All students in 90210 must have a C grade, and all in 20511 a B, or the correlation is not 100%. But we know that that is untrue. Some students in 90210 get A grades, and some are awarded D grades. There is variation within the student body that is caused by will, ability, and parental expectation among other things. So it is patently untrue that “the correlation between student achievement and zip code is 100 percent.” Domenech should be made to sit in the corner with a dunce cap until he learns his lesson. (Perhaps the problem is that we no longer do such things).

As a responsible citizen and voter, the most important thing you can do to make informed decisions is to arm yourself with basic math skills and not be afraid to challenge those who appear to be speaking from a position of authority. Our intellectual and political elite are not always completely accurate, sometimes from ignorance and sometimes from calumniation. I’m sure that you are shocked.

For whom the teachers toil?

Polly Smrcka (yes, that’s spelled correctly), is a lovely nonagenarian who has written several charming books about growing up in pre-electrified, early 20^th century rural Northwestern Pennsylvania. My favorite is “Hatch Hollow Tomboy”, in which the extraordinarily unfeminine yet adorable young Polly regales us with tales of catching bullfrogs in the summer and milking obstinate dairy cows by kerosene lantern in the deep winter darkness.

She also describes the one room school house with “Old Baldy” the teacher managing all grades K-12. Mr. Summerton had been hired directly by a committee of parents and did their bidding in the education of their children.

Contrast that to the Swampscott MA school district that, famously and notoriously, recently ordered all parents to a mandatory meeting during which they were forbidden to speak. It seems that our government funded and staffed schools have forgotten for whom they toil. It is the citizens and parents who pay the bills and fund the schools. There is no “government money” that does not originate from the taxpayer. Somehow the reporting relationship has become twisted and fouled. It is time for the belabored Swampscott citizens to reclaim control. A broader lesson for us all.

Individual mandate fantasies

Nationally syndicated columnist Froma Harrop credits Massachusetts’ individual mandate with having caused health insurance premiums to decline 40% since 2006 (http://www.creators.com/liberal/froma-harrop/so-you-thought-health-care-was-fixed.html).

I don’t know in which alternate universe she is living, but Governor Deval Patrick fervently wishes to join her there. Unfortunately, he can’t and is dealing with seriously escalating premiums.

The Massachusetts Division of Health Care Finance and Policy (DHCFP) reports that “average monthly health insurance premiums increased 12% from 2006 to 2008.” And 2009 and 2010 offered no relief with significant premium increases continuing, bedeviling the governor and his administration.

DHFCP laments that “…personal health spending per capita is higher in Massachusetts relative to the nation and continues to rise.”

Contrary to Ms. Harrop’s fantasy, the Massachusetts individual mandate did not result in a reduction in premiums. Wishing it so is not enough; Governor Patrick is wishing mightily to no effect.

Remembering a legend

We recently watched the “The Last Waltz” for the umpteenth time. It has been termed “the most beautiful rock film ever made.” Directed by Martin Scorsese, the movie features “The Band” (Rick Danko, Levon Helm, Garth Hudson, Richard Manuel, and Robbie Robertson) with guest appearances by Paul Butterfield, Eric Clapton, Neil Diamond, Bob Dylan, Emmylou Harris, Ronnie Hawkins, Dr. John, Joni Mitchell, Van Morrison, Ringo Starr, Muddy Waters, Ronnie Wood, and Neil Young. Holy cow – if you have an affinity for the roots of rock and blues and jazz, how could you resist?

You may be aware that “The Band” was , for a time, Bob Dylan’s backup band, were active from 1964 to 1999, and are considered extremely influential in rock, country, roots rock, Americana, and blues rock.

We were particularly taken by Rick Danko, a Canadian singer and bass and keyboard player who worked with Dylan both in “The Hawks” and “The Band”. He died far too young in 1999.

We met Rick in 1994 thanks to our friend Tony Medeiros, the leader of a popular New England blues and jazz band “The Chili Brothers”. Rick was in town to perform at a speakeasy (well, it felt like one) out in the deep woods of southern Rhode Island not far from URI. It was a favorite haunt of students and was full of them chatting and flirting and smoking and drinking and playing pool. Tony and the Chili Brothers were Rick’s backup band and he performed a wide variety of music, many of them classics. During the performance, the crowd of students continued chatting and flirting and smoking and drinking and playing pool – they didn’t pay him a bit of attention.

What a loss for them. They were in the presence of a true musical legend and completely squandered the opportunity. Such is the naïvité of youth.

We sat with Rick and Tony at the bar and chatted before and after the performance. Rick was gracious and humble; an easy and entertaining conversationalist. Those kids’ loss was our gain; since they were ignoring us we had Rick to ourselves. A fabulous evening thus passed, brushing with musical fame and genius in the wilds of South County, Rhode Island. Rick Danko will be always be fondly remembered and deeply missed in our home.

How to buy firewood

Those Amish folks in northwestern Pennsylvania really had me spoiled. When you purchased a cord of firewood from them, it was a true cord (4’ x 4’ x 8’), clean and seasoned, all hardwood with plenty of heating power.

Unlike a nearby Massachusetts town, were a roadside pile of split firewood looked very attractive, but there must have been another pile in the back that they used for chumps like me. When delivered, it was dirty and wormy and split small with lots of odd 8” chunks, far short of a full cord. Yuck.

Maybe the difference is that the Amish around Spartansburg, PA, believe in the ethical dictum of value offered for value received. Whatever the case, we must be more careful here. And for once the Commonwealth is on your side.

Massachusetts General Law Chapter 94, Section 298, controls the sale of firewood and prescribes the standard units of measure to be used for advertising and sale. (If your state doesn't have a law like this, perhaps it should).

There is a lot of confusion in terminology regarding firewood. A full cord is 128 cubic feet, measured as a closely stacked pile four feet high by four feet wide by eight feet long (4'x4'x8'). A face or stove or furnace cord is 4’ x 8’, but less than 4’ wide. Because of the potential confusion, MGL 94.298 requires that firewood be advertised and sold only in cubic feet, not in any variety of cord. In fact, the law specifically requires that “the terms ‘cord’, ‘face cord’, ‘pile’, ‘truckload’ or terms of similar import shall not be used in the advertising and sale of cordwood or firewood.”

Further, Massachusetts requires that firewood be “sold only in terms of cubic feet or cubic meters which will be construed as indicating the closely stacked cubic foot or cubic meter content to be delivered to the purchaser.” When you see an advertisement for a cord or half-cord of wood, it is unlawful in Massachusetts. Even when specified in terms of cubic feet, a description of “bulk loaded” violates the “closely stacked” requirement.

So what’s the poor consumer to do? Here are a few suggestions.

• To optimize the heating value of your wood, request seasoned hardwood (typically oak).
• Require a written receipt giving the following information:
  

a. Name and address of seller and purchaser
b. Date of Delivery
c. Quantity in terms of cubic feet
d. Price of quantity delivered

• Write down the license number of the delivery vehicle.
• Stack the wood closely – cross-stacking is not acceptable for determining the quantity delivered. If it measures less than the contracted amount, contact the seller before burning any of it.
• If the seller does not make good on the shortage, contact the Massachusetts Division of Standards:

Division of Standards
One Ashburton Place, Room 1115
Boston, MA 02108
(617) 727-3480

There is nothing more comforting than a crackling fire in your fireplace or woodstove, especially when a blizzard has knocked out your furnace. But please make sure that you got what you paid for.