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Observation selection bias

From the Titelbaum book on Bayesian epistemology I have mentioned here before.  There is a nice explanation in a footnote near the end about "observation selection bias" as a ubiquitous problem in statistics and, really, in the understanding of probability. The explanation is illustrated with a World War II throwback. US War Department statisticians observed in 1943 that bombers returning to London from their flights over occupied Europe generally had more bullet holes in their fuselage than in their engine. Somebody drew the conclusion that the German fire tended to hit the fuselage, and that there should be extra plating there.   Such a reinforcement of the fuselage was not a decision to be taken lightly.  Reinforcement adds weight. Heavier aircraft are less maneuverable, have a lesser range, etc.  So Abraham Wald, a Hungarian Jew known before the war for econometrics research, who at this point was working at Columbia with the Statistical Research Group, consulting with th
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Election Day: The incumbent and the veep

  Diane and I were talking recently about how the incumbent President, Joseph Biden, has seemed to do relatively little campaigning for his Vice President, Kamala Harris.  We both agree on that observation, but we had different interpretations.  My initial thought was, "Maybe Joe is grumpy.  Yes, he has supported her and done everything he had to as a party guy, but he was dumped over and may be ticked off." Diane thought this must be wrong.  The reason is more likely not that he is grumpy about campaigning but that she and her team have decided he is more a liability than an asset on the trail.  Whatever.   Looking at this from a broader PoV. Harris is in a familiar position in US presidential history. She cannot seem to be disloyal to the incumbent president whose mantle she has inherited -- nor can she present herself as a mere acolyte. She has to be both her own woman and a loyal party gal.  It is easy to get this wrong. George H.W. Bush annoyed a number of Reagan admirer

There is no GameStop MOASS coming

  Sorry.  There is none.  There is a cult on Reddit that consists of folks who tell either other that they're all about to get rich with their collection of modestly priced GameStop stock, or options.  The coming apocalyptic event that will lift the true believers into the heaven of obscene wealth is known as: the GameStop MOASS. MOASS stands in turn for "mother of all short squeezes." For those who aren't familiar with matters financial and don't know what a "short squeeze" is ... let me just say that it is the mirror image of a traditional stack market panic.  An old-school panic is a situation in which the price drop of a stock sets off a sudden belief that the stock will go further down, and a rush to sell it in time to get SOME value out of the sale.  That rush to sell is a self-fulfilling prophecy: it does drive the stock price down. A short squeeze is the opposite.  It is where people (generally those who have bet that a stock will fall in value -

Humor and Halloween

I'm pasting in here material I first posted in this blog years ago, when I was thinking (with ironic seriousness) about the philosophy of humor,  Now, less serious, I simply post it as appropriate to this time of year. --------------------------------------------------------------------------------------------------------------------- The Simpsons  a few years back did a Halloween episode set in the 1930s. The town of Springfield was ripped apart by panicked mobs after a radio program put together by a young Orson Welles that presented fake news reports of a Martian invasion. The next morning, Orson Welles is on his way out of town. He is met by the police chief who has just been surveying the damage done by the riots. This dialog ensures: Chief Wiggum: Why shouldn't I punch you in the nose, bud?! Orson Wells: (muttering to himself), Nose bud? Hmmmm. Is that funny?

How we think (1920)

Book note.    An important but neglected work by John Dewey, published by DC Heath, Boston, 1910, and one in the public domain, is known as How we think . Here is a link.  https://gutenberg.org/cache/epub/37423/pg37423-images.html  How we think opens in striking fashion, "No words are oftener on our lips than thinking and thought. So profuse and varied, indeed, is our use of these words that it is not easy to define just what we mean by them." That phrasing could have led to a Wittgensteinian view of such definitions as games, where usage drives meaning rather than the reverse.   It doesn't go there. Rather: the first chapter comes to the conclusion that thinking is "that operation in which present facts suggest other facts (or truths) in such a way as to induce belief in the latter upon the ground or warrant of the former."  He suggests a man out for a walk who notices a cold breeze.  This may induce him to look toward the sky, which may in turn appear cloudi

Margaret Fuller

  I mentioned Fuller the week before last, even posting a portrait of her above a list of key philosophers of the 18th and 19th centuries. Let us say a bit more.... She did not have a long life (1810 - 1850), dying in a shipwreck on a sandbar near Fire Island, attempting to return to the US after a trip to Italy.  Fuller was associated with the Transcendentalist movement of the day, and with its organ The Dial, which she edited 1840 - 44. She brought a distinctive tone to that periodical, described sometimes as "noisy, histrionic and sincere," in contrast to the more cerebral and somewhat ironic distanced tone one finds in Emerson's essays.  Philosophically, she was an unabashed Platonist. This meant that there was a Reason that surpassed understanding -- understanding is something we can get WITHIN the cave,  “Reason” is the faculty through which a wise person conducts the Platonic Quest to go beyond the material in search of the ideal.  Emerson, to continue the contrast

China's realty-development garden has a zombie?

 Meanwhile, in a distant land, Country Garden struggles to get out of its hole. One year and two days ago I posted here about the huge Chinese realty developer and its default on its bonds.  The broader issue, worth noting from the other side of the world, is: the PRC allows huge companies to continue in operation after they have ceased to be economically viable yet without restructuring or liquidation.  It is known as the "zombie companies" issue and the zombies are a drain on the productivity of the economy as a whole (though, no, we cannot even metaphorically say that they eat its brains).  https://jamesian58.blogspot.com/2023/10/news-from-china-country-garden-story.html The question after the default was: would Country Garden become such a zombie?  https://www.bloomberg.com/news/articles/2024-10-09/country-garden-misses-target-date-for-restructuring-backing Nothing new to report, one might say: but that fact IS the news worth reporting. Bloomberg is now reporting that the