March Madness

March 18, 2009
Posted by Jay Livingston

“When Losing Leads to Winning.” That’s the title of the paper by Jonah Berger and Devin Pope. In the New York Times recently, they put it like this:

Surprisingly, the data show that trailing by a little can actually be a good thing.
Take games in which one team is ahead by a point at the half. . . . The team trailing by a point actually wins more often and, relative to expectation, being slightly behind increases a team’s chance of winning by 5 percent to 7 percent.
They had data on over 6500 NCAA games in four seasons. Here’s the key graph.

(Click on the chart for a larger view.)

The surprise they refer to is in the red circle I drew. The dot one point to the left of the tie-game point is higher than the dot one point to the right. Teams behind by one point at the half won 51.3% of the games; teams leading by a point won only 48.7.*

Justin Wolfers** at Freakonomics reprints the graph and adds that Berger and Pope are “two of the brightest young behavioral economists around.”

I’m not a bright behavioral economist, I’m not young, I’m not a methodologist or a statistician, and truth be told, I’m not much of an NCAA fan. But here’s what I see. First of all, the right half of the graph is just the mirror image of the left. If teams down by one win 51.3%, teams ahead by one have to lose 51.3%, and similarly for every other dot on the chart.

Second, this is not the only discontinuity in the graph. I’ve put yellow squares around the others.


Teams down by 7 points at the half have a slightly higher win percentage than do teams down by 6. By the same graph-reading logic, it’s better to be down by 4 points than by only 3. And the percentage difference for these points is greater than the one-point/tie-game difference.

Then, what about that statement that being down by one point at the half “ increases a team’s chance of winning by 5 percent to 7 percent”? Remember, those teams won 51.3% of the games. How did 1.3 percentage points above 50-50 become a 5-7% increase? You have to read the fine print: “relative to expectation.” That expectation is based on a straight-line equation presumably derived from the ten data points (all the score differentials from 10 points to one – no sense in including games tied at the half). That model predicts that teams down by one at the half will win only 46% of the time. Instead, they won 51.3%.

Berger and Pope’s explanation of their finding is basically the Avis factor. The teams that are behind try harder. Maybe so, but that doesn’t explain the other discontinuities in the graph. Using this logic, we would conclude that teams behind by seven try harder than teams behind by six. But teams behind by 5 don’t try harder than teams behind by four. And so on. Why do only some point deficits produce the Avis effect?


* Their results are significant at the .05 level. With 6500 games in the sample, I’d bet that any difference will turn out to be statistically significant, though the authors don’t say how many of those 6500 games had 1-point halftime differences.

**Wolfers himself is the author of another economics journal article on basketball, a study purporting to reveal unwitting racism among NBA referees. In that article as well, I thought there might be less there than meets the economist’s eye.

Having Trouble Getting Through "Surveiller et Punir"?

March 16, 2009
Posted by Jay Livingston

Post Secret (is there anyone who still doesn’t know about it?) is just what it says: postcards of secrets. People send them anonymously since the secrets are usually the sort of thing you’d want to keep secret – actions, thoughts, feelings, and biographical facts that might be stigmatizing.

And then there was this, from yesterday’s batch – not nearly so interesting as, say, the one from the woman whose boyfriend didn’t bring her to orgasm so she masturbated with a loaded gun, which did,
  – but of more sociological relevance.

The Best, The Brightest, The Bonuses

March 15, 2009
Posted by Jay Livingston

The headline today is about the $165 in bonus money going to AIG executives.

I guess don’t understand the concept of a bonus. I thought it was extra money you got for actually doing something. Something good.


Athletes have bonuses written into their contracts. ARod gets $1.5 M if he wins the MVP; $6M if he equals Ruth’s home run total. Steinbrenner figures that these achievements will also bring more money to the Yankees.

AIG is a sort of bizarro ARod, the worst of the worst in the economic collapse. The insurance company leverage rate of 11:1 was about three times that of other firms. But when it came to the really risky stuff – the credit default swaps and derivatives – they were leveraged at 35:1 (my source here is Jon Stewart in his tête-à-tête with Jim Cramer). So guess who’s getting most of the $165 million.

http://www.nytimes.com/2009/03/15/business/15AIG.html?_r=1&hp
Edward Liddy, chairman of AIG, had two reasons the bonuses had to be paid. One is that AIG was contractually obligated. They had promised the money “early in 2008, before the company’s near collapse, when problems stemming from the mortgage crisis were becoming clear.” To me, this sounds as though the insiders at AIG, when they saw that the company was heading for a heavy fall, stuffed their pockets with as much of the cash as they could.

The second argument for paying the bonuses is even better.

http://www.nytimes.com/2009/03/15/business/15AIG.html?_r=1&hp

The best and the brightest. Either Mr. Liddy has a wonderfully understated sense of irony or he does not remember the history of that phrase. The Best and the Brightest was the title of David Halberstam’s book about the people who brought us Vietnam. The architects of that debacle, like the financial geniuses responsible for the current meltdown, were men of high IQ and fancy education. Yet their ideas and theories took the US into the most disastrous foreign policy debacle in its history, at the time.

Update: Judith Warner, in her New York Times blog today, discusses the phrase, with references to Halberstam, but also to Shelley and Henry Adams, whose use of if beat Halberstam by roughly 100 and 50 years, respectively.

To Turnitin or Not to Turnitin

March 13, 2009
Posted by Jay Livingston

Turnitin.com, scourge of plagiarizing students, might be just a little bit too picky. And those student claims of innocence might just be true.

Inside Higher Ed
reports on a study of Turnitin and SafeAssign (a part of Blackboard I didn’t know about) done at Texas Tech. The researchers submitted 400 papers to both services. Turnitin pointed its accusing finger 2-3 times as often as did SafeAssign.

The big problem is that Turnitin is just too damned suspicious.

http://www.insidehighered.com/news/2009/03/13/detect

Thanks Ed (Inside Higher Ed and I are on a last-name basis), but I figured this out by myself a couple of weeks ago. We don’t have Turnitin at Montclair, but one of our adjuncts uses it, and he failed a student for plagiarizing a paper. She protested. So the matter was referred to the department chair – me. The teacher sent me the Turnitin report, and there it was in black and white: Her 1400-word paper on Filipino Americans had a “similarity index” of 69%.
(Click on the image for a larger view.)

I’d never seen a Turnitin report, so I checked out some of the sources. The first flagged item was the following.
The Philippines is located in the southeastern portion of Asia. Her neighbor on the north is the republic of China (Taiwan of Formosa), while on the west is Communist Vietnam.
I entered the URL of the source (#2 in the summary sheet in the picture above. In case the print is too small for you to read, it’s filipinamates.com. Turnitin was hot on the scent, and I followed. This was the first screen I found.

Not wanting to let a clear case of plagiarism slip by, I had to click on Enter. I found myself with this menu.


I won’t bore you with the details of my further searches for the sources of plagiarism offered by this menu except to say that Trekkie Monster from “Avenue Q” was right.

The other sources listed by Turnitin were equally non-inculpatory though not nearly so interesting. If you write in your paper that the area of Mindanao is 36,670 square miles, and someone else put that fact in their paper or on their website, you’re toast in Turnitin’s book. It even flagged passages the student had put in quotation marks.

To quote Ed again, “All of the members of the Texas Tech team said that they emerged from their study with serious reservations about using the services.”

So did I.