Monthly Archives: December 2010

Reader survey: how seriously do you take expected utility?

Slate reposted an old piece of mine about the lottery, on the occasion of tonight’s big Mega Millions drawing.  This prompted an interesting question on Math Overflow:

I have often seen discussions of what actions to take in the context of rare events in terms of expected value. For example, if a lottery has a 1 in 100 million chance of winning, and delivers a positive expected profit, then one “should” buy that lottery ticket. Or, in a an asteroid has a 1 in 1 billion chance of hitting the Earth and thereby extinguishing all human life, then one “should” take the trouble to destroy that asteroid.

This type of reasoning troubles me.

Typically, the justification for considering expected value is based on the Law of Large Numbers, namely, if one repeatedly experiences events of this type, then with high probability the average profit will be close to the expected profit. Hence expected profit would be a good criterion for decisions about common events. However, for rare events, this type of reasoning is not valid. For example, the number of lottery tickets I will buy in my lifetime is far below the asymptotic regime of the law of large numbers.

Is there any justification for using expected value alone as a criterion in these types of rare events?

This, to me, is a hard question.  Should one always, as the rationality gang at Less Wrong likes to say, “shut up and multiply?” Or does multiplying very small probabilities by very large values inevitably yield confused and arbitrary results?

UpdateCosma Shalizi’s take on lotteries and utilities, winningly skeptical as usual.

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2010 booklist

Below please find the books I read in 2010.  Only four of these came out this year, and two of those were books I reviewed; so I think I’m officially out of touch again.  (Though four more on the list came out in the second half of 2009.)

Best of the Year:  Tough choice:  I read a lot of novels this year which had great features but made bad choices, too.  In the end, I’ll pick the one book I unreservedly liked all the way through, Matthew Derby’s Super Flat Times. There is this genre that Ben Marcus invented for The Age of Wire and String, and Derby is the first person other than Marcus to use it.  Maybe more precise would be to say that Super Flat Times is the proof that the genre is a genre, adaptable to different purposes, and not just the class of books Ben Marcus can write.  From “The Sound Gun” (click to read the whole story at Conjunctions)

The Sound Gun has four settings. The first one is Make Scared. Make Scared makes a big loud noise that makes people scared. It is louder and scarier than the noise a bomb makes as it explodes, because the people we’re fighting have not been scared by that sound for three wars. The sound that Make Scared makes is like a herd of elk tumbling into a cauldron of hot, resonant dung, or, at night, the frail puff of air conjured up by a dying child. Make Scared worked for a while, but then the enemy started putting soaked wheat pods in their ears, so we had to move on to Hurt.

Should have blogged about but didn’t: The Halo Effect, a bracingly skeptical business book that dares to ask whether we have any way at all of telling good CEOs from bad ones in real time.  The charming American Nerd, from which I learned that Continental literary theory is now an important part of high-school debate.

Books mentioned on the blog are linked, as usual.

28 Dec 2010:Never Let Me Go, by Kazuo Ishiguro.
22 Dec 2010:Colors Insulting to Nature, by Cintra Wilson.
1 Dec 2010:Fame, by Daniel Kehlmann. (Carol Janeway, trans.)
24 Oct 2010:The Bridge on the Drina, by Ivo Andric. (Lovett Edwards, trans.)
4 Oct 2010:Eating the Dinosaur, by Chuck Klosterman.
28 Sep 2010:Shut Up, I’m Talking: and other diplomacy lessons I learned in the Israeli government, by Gregory Levey.
24 Sep 2010:Stalag Wisconsin: Inside WWII Prisoner-of-War camps, by Betty Cowley.
18 Sep 2010:Tragic Magic, by Wesley Brown.
4 Sep 2010:Under the Dome, by Stephen King.
1 Sep 2010:Proofiness, by Charles Seife.
25 Aug 2010:The Halo Effect: and the eight other business delusions that deceive managers, by Phil Rosenzweig.
11 Aug 2010:My Life As a Fake, by Peter Carey.
9 Aug 2010:The Financial Lives of the Poets, by Jess Walter.
2 Aug 2010: Born Standing Up, by Steve Martin.
29 Jul 2010:Eat the Document, by Dana Spiotta.
25 June 2010:Duel at Dawn: Heroes, Martyrs, and the Rise of Modern Mathematics, by Amir Alexander.
27 May 2010:Then We Came To The End, by Joshua Ferris.
11 May 2010:American Nerd: The Story of My People, by Ben Nugent.
7 May 2010:The Ask, by Sam Lipsyte.
18 Apr 2010:A Gate at the Stairs, by Lorrie Moore.
11 Apr 2010:Perdido Street Station, by China Mieville.
23 Mar 2010:The Last Chronicle of Barset, by Anthony Trollope.
8 Feb 2010:His Illegal Self, by Peter Carey.
20 Jan 2010:Super Flat Times, by Matthew Derby.
16 Jan 2010:In Persuasion Nation, by George Saunders.

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Weird NYT walkback on the Hauser case

The New York Times recently revisited the case of Marc Hauser, the Harvard psychologist accused of research fraud.  Nicholas Wade’s new article suggests that Hauser might be more sloppy than dishonest, the victim of a bureaucratic legal process that makes no allowances for innocent mistakes, and that the situation is starting to turn in Hauser’s favor:

Also last month his principal accuser outside of Harvard, Gerry Altmann, allowed that he may have spoken too hastily. Dr. Altmann is the editor of Cognition, a psychology journal in which Dr. Hauser published an article said by Harvard to show scientific misconduct.

When first shown evidence by Harvard for this conclusion, Dr. Altmann publicly accused Dr. Hauser of fabricating data. But he now says an innocent explanation, based on laboratory error, not fraud, is possible. People should step back, he writes, and “allow due process to conclude.”

Here’s Altmann’s response:

[Wade] selectively quotes from me to support the contention that the discrepancy between Hauser’s raw data and the published data were due to “devastating error, but not fraud”. In fact, there has been no stepping back. As I make very clear in this blog (and repeated in emails to Mr. Wade – see below), the information I have received, when taken at face value, leads me to maintain my belief that the data that had been published in the journal Cognition was effectively a fiction – that is, there was no basis in the recorded data for those data. I concluded, and I continue to conclude, that the data were most likely fabricated.

From there, the article gets feisty and strange.

Dr. Hauser’s difficulties began in 2007 when university officials went into his lab one afternoon when he was out of the country and publicly confiscated his records, an action based on accusations by some of his students.

For the next 18 months he had no idea what he was accused of.

Well, unless he actually had fabricated data, in which case he might have had a tiny shred of an idea.

A troika of Harvard department heads then delivered a secret report.

Hold on now, that sounds Russian!

Then there’s this:

Harvard’s investigation has been “lawyer-driven,” says a faculty member who spoke on condition of anonymity, and has stuck so closely to the letter of government-approved rules for investigating misconduct that the process has become unduly protracted — it lasted three years — and procedurally unfair to the accused.

“I think it legitimate to ask why the Harvard brass did not push back against their lawyers,” this member said. “At Harvard we now have the Un-Larry administration — no risk-taking, no thinking outside the box, no commitment to principles that challenge standard university practice,” he said, referring to Harvard’s previous president, the economist Larry Summers.

It’s not clear to me why Harvard’s lawyers would be so keen on besmirching a distinguished and popular professor, or how bending the rules to avoid bringing charges against Hauser would demonstrate a “commitment to principles.”

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December linkdump

Noted with minimal comment:

  • Add to Ellie Kemper another former student making it in showbiz:  Damien Chazelle, who was actually in high school when I taught him number theory, had a feature in the Tribeca Film Festival.
  • Can William Langewiesche write a boring magazine feature?  If so, it is not this one about a Brazilian prison gang.  (Langewiesche previously on this blog.)
  • The Judybats are more thoroughly forgotten than they should be.  Frontman Jeff Heiskell, a decade after the last Judybats release (and fifteen years after the last Judybats release anyone heard)  sounds bitter about it.  If you like the fact that Heiskell says, in this interview, “My rectum draws up tight like a little antique button,” you will probably like their records.  Here’s the video for “Native Son.”  Look at these beautiful 1990s mid-South college town hepcats!
  • Yellow Ostrich was a band from Appleton and now is a band from Brooklyn like everyone else.  They put on a great show at the Gates of Heaven synagogue last spring, right before the move east.  Here’s the simple and compelling “Whale”:
  • People like to complain that today’s parents are too fond of giving kids names with novelty spellings.  But have you met a kid named Gregg lately?
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Ngrams: one more way to win an argument using Google

I thought I’d never see a definitive answer to this one, but thanks to the brand-new Google NGrams Viewer, the facts are clear:

It is “another think coming,” and it has always been “another think coming.”

A lot of words and phrases (though not these) show a dip starting in 2000 or so.  I wonder if the nature of the corpus changes at that point to include more words?  You see the same effects with name frequencies — the frequency of any given name has been decreasing over the last twenty years, just because names are getting more and more widely distributed; the most popular names today take up a smaller share of namespace than much lower-ranked names did in the 1950s.  A quick and dirty thing to check would be the entropy of the word distribution; is it going up with time?

Lots of good ngram examples on Tom Scocca’s blog, here and here.

Oh, and here’s the Four Shortstops:

Ripken, appropriately, is showing great staying power.

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The initial “Why”

You know what’s a lost art?  Starting a sentence with “Why.”  It’s so antique, in fact, that I can’t articulate when you’re allowed to do it.

I understand that the initial “Why” can denote mild surprise:

Why, I had no idea you were from Boonestown!

or some kind of vague intensification:

Why, you dirty rat

or can function something like intial “Well”:

Why, it’s quite simple, Maxine….

or can even serve as a phonetic wind-up:

Why, I oughtta…

But you clearly can’t put “Why” before any old declarative sentence:  my idiolect rejects “Why, I’ll have the eggs benedict and a coffee.”

Can anyone put their finger on the underlying rule here?

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Split-screen blackboard

From Andrew Gelman, an interesting pedagogical suggestion:

The split screen. One of the instructors was using the board in a clean and organized way, and this got me thinking of a new idea (not really new, but new to me) of using the blackboard as a split screen. Divide the board in half with a vertical line. 2 sticks of chalk: the instructor works on the left side of the board, the student on the right. On the top of each half of the split screen is a problem to work out. The two problems are similar but not identical. The instructor works out the solution on the left side while the student uses this as a template to solve the problem on the right.

Has anyone tried anything like this?  It sounds rather elegant to me.

 

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Licensing changes at the Online Encyclopedia of Integer Sequences

Neil Sloane’s invaluable OEIS has just launched its new page, featuring among other things a wiki and a backend that allows the encylopedia to grow with much less personal supervision from Sloane himself.  But not all the changes are welcome:  William Stein points out the new end-user licensing agreement, which is much more restrictive than previously.  Here’s what William posted to the number theory listserv:

…there are now new and very significant restrictions on using OEIS content:
“To make copies, distribute, make Adaptations and make copies of and
distribute the Adaptations, of no more than 5% of the OEIS Content”.
This is in sharp contrast to how OEIS was before, where, e.g., there
was a file  http://oeis.org/stripped.gz  that contained the sequences
themselves.  (This matters to me, since we make them available for
Sage, with a nice interface.)  This was an incredibly useful tool,
since it meant that even without internet access (or in a secure
closed network), one could do searches of OEIS, which is in my opinion
a critical research tool that was built partly by the effort of the
community (you).   Distribution of this stripped.gz file now appears
to be illegal.

I think the recent direction OEIS is going in is unfortunate.  It’s
the exact opposite of how, e.g., Wikipedia operates.  Anybody can
mirror Wikipedia content, there is a complete 6GB tarball you can
download that contains all article, etc.

So before signing up for an account, and signing away the rights to
all data or sequences you’ve submitted, please consider the above.

I will not be registering or contributing to OEIS until the license changes.

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Ankylosaurus, on the other hand, was totally in earnest

At the American Museum of Natural History with CJ and AB, I learned that the best modern thinking gives Tyrannosaurus Rex just two fingers on each hand, not three.

It must have been very demeaning to be killed and eaten by a creature making the ironic quotation gesture.

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