Recent blog posts by Michael Schaffer and Hendrik Herzberg nicely characterise the feeling of futility provoked by trying to track and understand all of the variables involved in the ongoing US election. It is very difficult to get a sense both of political events, and of the media and popular reactions to those events. Still, perhaps predictions are possible without understanding. Indeed, there is very good reason to think that the best available predictions in a case of this kind will go independently of understanding (see here and here for why). Unfortunately, the depression associated with attempting to understand politics is not lightened by examining the statistical factors behind political judgement instead. To wit:
Alexander Todorov, Anesu N. Mandisodza, Amir Goren, and Crystal C. Hall, “Inferences of Competence from Faces Predict Election Outcomes“, in Science, Vol. 308, No. 5878, 10 June 2005, pp. 1623–1626.
We show that inferences of competence based solely on facial appearance predicted the outcomes of U.S. congressional elections better than chance (e.g., 68.8% of the Senate races in 2004) and also were linearly related to the margin of victory. These inferences were specific to competence and occurred within a 1-second exposure to the faces of the candidates. The findings suggest that rapid, unreflective trait inferences can contribute to voting choices, which are widely assumed to be based primarily on rational and deliberative considerations.
Now of course, good polling methods will do better than facial appearance judgements with respect to predicting outcomes, and do not produce any depressing thoughts, unless we include the depressing thought that these polls tend to be close even in elections such as this one where the superior candidate is clear. (Still, I would be interested in seeing a test of facial appearance judgements on Obama and McCain). Even better than polling, however, are prediction markets:
Joyce E. Berg, Forrest D. Nelson and Thomas A. Rietz, “Prediction market accuracy in the long run“, in International Journal of Forecasting, Vol. 24, No. 2, April-June 2008, pp. 285–300.
“Prediction markets” are designed specifically to forecast events such as elections. Though election prediction markets have been being conducted for almost twenty years, to date nearly all of the evidence on efficiency compares election eve forecasts with final pre-election polls and actual outcomes. Here, we present evidence that prediction markets outperform polls for longer horizons. We gather national polls for the 1988 through 2004 U.S. Presidential elections and ask whether either the poll or a contemporaneous Iowa Electronic Markets vote-share market prediction is closer to the eventual outcome for the two-major-party vote split. We compare market predictions to 964 polls over the five Presidential elections since 1988. The market is closer to the eventual outcome 74% of the time. Further, the market significantly outperforms the polls in every election when forecasting more than 100 days in advance.
This is from a special issue of the journal on election forecasting, in which the introduction (published online on 25 March 2008) to the issue concludes:
To summarize, of the forecasters here who brave a clear prediction, all name the Democrats. Of course, these are mostly speculations about the forecasts that will be firmed up by later in the summer and early fall. Even so, they suggest that this may be a good year for the Democrats. But when, as forecasters, we climb out on the limb, we know it may get sawed off.
For times when the drum of expert judgements becomes deafening, the graph for the Iowa Electronic Markets 2008 US Presidential Election Winner Takes All Market can be seen here. Free markets might not be good for economies, but—in contrast to the human brain—they are surprisingly good at synthesising information.
The pastor whose prayer Sarah Palin says helped her to become governor of Alaska founded his ministry with a witchhunt against a Kenyan woman who he accused of causing car accidents through demonic spells.
Hannah Strange, “Palin linked electoral success to prayer of Kenyan witchhunter“, in Times Online, 16 September 2008.
“And face it—McCain and Weaver were maniacal about Ralph Reed and Norquist. They were sticking little pins in dolls because those guys had cost him South Carolina”.
Jo Becker and Don Van Natta Jr, “McCain and Team Have Many Ties to Gambling Industry“, in New York Times, 28 September 2008.
Mr. Fish, “A Cartoon“, in Harper’s, 26 September 2008.
Paul Doyle, “Chelsea’s potency uninterrupted by limp Bordeaux”, in The Guardian, 17 September 2008.
In 1677, the most unpopular law of the old customary code was finally abolished in France. Congrès was defined by the Frutière dictionary as: “the practice of coitus ordered by decree of an ecclesiastical judge, performed in the presence of surgeons and matrons, to discover whether a man is potent, with a view to dissolving a marriage.”
The reason it was scrapped had, of course, nothing to do with public decency. Rather it was because the authorities belatedly came to realise that the exercise did not elicit conclusive proof of impotence. “Our organs do not always obey us when we would like them to, still less so in front of judges,” blubbed one contemporary, as quoted in Nina Epton’s delicious 1959 opus Love and the French.
I emphasise that these are the first two paragraphs of a review of a sporting match.
In related news, international voters prefer Obama to McCain by 4-1, and I hereby announce that I will be voting in this election, by proxy, since Chad and I resolved an argument over the obligation to vote by coming to the agreement that he will vote as I direct him to. Now let me think. The man with one car or the man with thirteen cars? The man who was the first black president of the Harvard Law Review, or the man who graduated 894th out of a class of 899 at the Naval Academy? A vice presidential candidate who is a long-time member and current chairman of the U.S. Senate Committee on Foreign Relations, or one who argues for her foreign policy credentials on the grounds that “you can actually see Russia from land here in Alaska”? An energy policy grounded on the principle that government incentives are required to transition to green energy sources, or a policy grounded on a belief in the unfettered free market principles that have the US economy doing so well right now (with a vice presidential candidate who has said that “I’m not one though who would attribute [global warming] to being man-made”, and who when elected mayor of a small town repeatedly asked about the possibility of censoring books in the public library)? It’s a tough choice, America.
My friend Tyler is starting a new radio show and you should all listen to it, as his blurb makes absolutely clear:
This show features a combination of field recordings and experimental sound art (Glenn Gould, John Cage, Janet Cardiff, Max Neuhaus), home-recorded folk and pop songs (Charlie Mcalister, Simon Joyner, Wio), as well as more traditional indie rock (Palace, Neutral Milk Hotel, Animal Collective) and British shoegaze (My Bloody Valentine, Slowdive, Cocteau Twins). I will focus primarily on artists who explore non-conventional recording techniques and experiment with ways of capturing sound outside of the studio context. More generally, rather than conceiving of radio as a means for merely transmitting prerecorded material, I am interested in approaching the medium as a potential site of artistic production – stitching together acoustic fragments and layers of static, noise, and junk, to create spontaneous sound collages. What would it sound like, for example, if one superimposed a handheld recording of an industrial dishwasher and two people fighting in a wooden room, on top of an audio biography of Helen Keller, and used the resulting chaotic garble as a segue between a Cocteau Twins song and a home-recorded folk song about owls and fried oysters? I suspect that, at the very least, certain familiar songs would be reenergized by the new contexts in which they were embedded and, if one listened even more closely, occult voices would eventually begin to emerge alongside the death rattle of the everyday. Running water would sound like fires in the street.
One of the very nice perks of working right up the stairs from Open Letter Books—I have just got my hands on a dog-eared advance reader’s copy of 2666.
Nathan W. Bailey, “Love will tear you apart: different components of female choice exert contrasting selection pressures on male field crickets”, in Behavioral Ecology, Vol. 19, No. 5, September-October 2008, pp. 960–966. [URI]
Lay Summary
Theory predicts that exaggerated male ornaments can evolve through the action of female choice for those ornaments. Female choice consists of the preferences that females exert, which can be characterized by functions describing how the probability of mating relates to variation in male traits. In addition, females can vary in how responsive they are to male mating signals either by adjusting how many potential mates they respond to or by altering the effort, or speed, of their response. Discrimination describes how strongly females distinguish between male trait values. Little is known about how these behavioral components interact to produce final mating decisions, but such information is necessary to better understand the behavioral basis of male ornament evolution. I performed mate choice experiments using the field cricket, Teleogryllus oceanicus, and found that individual females varied widely in the shape of their preference functions for male song traits. Some components of female choice appeared to be behaviorally linked: more responsive females were more discriminating, but only when response likelihood was considered. Discriminating females were also more likely to show stabilizing preference functions favoring intermediate male trait values. Finally, I used two methods to construct population-wide preference functions with pooled response data from all females. The first method used female response likelihood as a proxy for female mating probability and generated a strongly linear function that favored extreme male song values. The second method used female response effort as a proxy for mating probability and revealed a strongly stabilizing function that favored intermediate trait values. The outcome of female choice in a wild setting ultimately depends on the relative importance of response number versus response effort, where exogenous factors such as predation risk or density will determine which component of female choice predominates mating decisions.
