Thursday, November 29, 2012

Is everything we eat associated with cancer? A systematic cookbook review

Objective: We aimed to examine the conclusions, statistical significance, and reproducibility in the literature on associations between specific foods and cancer risk.

Design: We selected 50 common ingredients from random recipes in a cookbook. PubMed queries identified recent studies that evaluated the relation of each ingredient to cancer risk. ...

Results: Forty ingredients (80%) had articles reporting on their cancer risk. Of 264 single-study assessments, 191 (72%) concluded that the tested food was associated with an increased (n = 103) or a decreased (n = 88) risk; 75% of the risk estimates had weak (0.05 > P ≥ 0.001) or no statistical (P > 0.05) significance. Statistically significant results were more likely than nonsignificant findings to be published in the study abstract than in only the full text (P < 0.0001). Meta-analyses (n = 36) presented more conservative results... The [relative risks] from the meta-analyses were on average null (median: 0.96; IQR: 0.85, 1.10).

Conclusions: Associations with cancer risk or benefits have been claimed for most food ingredients. Many single studies highlight implausibly large effects, even though evidence is weak. Effect sizes shrink in meta-analyses.
--Jonathan Schoenfeld and John Ioannidis, American Journal of Clinical Nutrition, on the weak link between food and cancer. HT: ACT

Wednesday, November 28, 2012

Keeping your eye on the ball to improve sports performance

Back in elementary school gym class, virtually all of us were taught to keep our eyes on the ball during sports. But a growing body of research suggests that, as adults, most of us have forgotten how to do this. ...

Which is in part why the British researchers had half of their group of 40 duffers practice putting technique, while the other half received instruction in a gaze-focusing technique known as “Quiet Eye” training.

Quiet Eye training, as the name suggests, is an attempt to get people to stop flicking their focus around so much. But “Quiet Eye training is not just about looking at the ball,” says Mark Wilson, who led the study, published in Psychophysiology, and is a senior lecturer in human movement science at the University of Exeter in England. “It is about looking at the ball for long enough to process aiming information.” It involves reminding players to first briefly sight toward the exact spot where they wish to send the ball, and then settle their eyes onto the ball and hold them there.

This tight focus on the ball, Dr. Wilson says, blunts distracting mental chatter and allows the brain “to process the aiming information you just gathered” and direct the body in the proper motions to get the ball where you wish it to go. ...

And in fact, after Dr. Wilson had his golfing volunteers practice for hours on either specific aspects of stroke technique or on focusing their gaze and not worrying about technique, those who had worked on their gaze were more accurate than those who had fine-tuned their technique. ...

Similar results have been reported among soccer penalty kickers...

[I]n a study published last year in the journal Cognitive Processing, collegiate players who were instructed to look briefly toward one of the upper, far corners of the goal and then immediately back to the ball, ignoring the goalie, significantly improved their shooting accuracy and reduced by 50 percent the number of times the goalie blocked their try, compared to teammates who didn’t quiet their gaze. ....

Dr. Wilson says, after having extensively studied just how the best golfers look, he now teaches novice golfers at his lab to “keep their gaze on the back of the ball, which is the contact point for the putter, for a brief period before starting the putting action” — long enough to, for instance, “say ‘back of the cup’ to themselves,” he says. The golfers are told to hold that position throughout the putting stroke and, he says, “importantly, after contact for a split second. I often ask golfers to rate the quality of their contact on the ball from 1 to 10, before they look up to see where the ball went.”
--Gretchen Reynolds, NYT, on the power of the gaze

Tuesday, November 27, 2012

The richest metropolitan areas in the U.S.

New Haven, CT: #18!

Bridgeport, CT makes it to #1 because the metro area includes Greenwich, even though the city of Bridgeport is struggling economically.

Source: Bureau of Economic Analysis via The Atlantic.

Why do liberal women want more sex than they're having?

OK, I’ve been at it again, meaning that I’ve been exploring associations between various measures in the New Family Structures Study (the NFSS). ...

At the risk of sounding blunt, crass, and insensitive, the NFSS data clearly reveal that—for whatever reason—more politically liberal 18-39-year-old women report wanting more sex than they’ve been having. (No such association appears among men. ...) ...

Here are the simple numbers: 16% of “very conservative” women say they’d prefer more, compared with 29% of conservative women, 31% of moderates, 47% of liberals, and 50% of “very liberal” women. ...

...women of all political stripes report statistically-comparable frequency of sex.

In regression models, the measure of political liberalism remains significantly associated with the odds of wanting more sex even after controlling for the frequency of actual intercourse over the past two weeks, their age, marital status, education level, whether they’ve masturbated recently, their anxiety level, sexual orientation, race/ethnicity, depressive symptoms, and porn use. ...

I floated this to a female friend, an economist, who offered this four-part theory:

1. More liberal women are less likely to be religious. (In the NFSS and other datasets, she’s correct in this). 
2. Given that, more liberal women are therefore more likely to have a difficult time attributing transcendent value to aspects of life such as their work, relationships, children, and daily tasks. Some scholars speak of this as “sanctifying daily life.” In other words, liberal women are less apt to conceive of mundane, material life as imbued with or reflecting the sacred. 
3. Nevertheless, most people experience sexual expression as–in some significant way–transcendent, or higher-than-other-experiences. 
4. More liberal women therefore want to have more sex because they feel the lack of sufficient transcendence in life. If sex is one of the few pathways to it, then it’s sensible to desire more of it.
Basically, liberal women substitute sex for religion. ...

So I added religious service attendance to the regression model described earlier, predicting wanting more sex, and—wouldn’t you know it—political liberalism finally went silent as a predictor. Barely.

Other theories are welcome…
--Mark Regnerus, Patheos, on the demand for transcendence. HT: Tim Dalrymple

Sunday, November 25, 2012

The Fox News and MSNBC of Lincoln's day

The next day [after the Gettysburg Address] the Democratic-leaning Chicago Times observed, "The cheek of every American must tingle with shame as he reads the silly, flat and dishwatery utterances of the man who has to be pointed out to intelligent foreigners as the President of the United States."

Friday, November 23, 2012

How noisy is economics/finance peer review?

My paper’s first main finding is a quantitative estimate of the objective component in the economics/finance refereeing process. Consider a scale defined by a single parameter that measures referee accuracy, named lambda. Lambda can be from 0 to 1 and measures the fraction of the referee report that constitutes an objectively agreeable paper quality. ... λ = 1 means that every referee reports the paper’s objective aspect. λ = 0 means that every referee reports noise. ...

The observed consensus estimates among referees were λ ≈ 0.30 for the Journal of Finance (JF) and Review of Financial Studies (RFS), λ ≈ 0.35 for Econometrica (ECMTA), the Quarterly Journal of Economics (QJE) and the SFS Cavalcade; and λ ≈ 0.40 for the International Economic Review (IER), the Journal of Economic Theory (JET), the Journal of the European Economic Association (JEEA), and the Rand Journal of Economics (Rand). 

Roughly, referee reports were one part signal, two parts noise. ...

For economics journals, when two referees are consulted, the top-10p [percentile] paper receives two rejects with probability 14%, one reject and one non-reject with probability 47%, and two non-rejects with probability 40%. With three referees, the top-10p papers receives a majority of reject recommendations with 30% probability, a majority of non-reject recommendations with 70% probability.

For finance journals, with their lower lambdas and higher rejection probabilities, the higher than 50% reject probability for the top-10p paper results in a strange situation: The more referees are consulted, the more likely it is that the referees will agree that the top-10p paper is bad. For this top-10p paper, with one referee, the probability that the majority of referees recommends rejection is 38%; with three referees, it is almost 70%. (This also obviates the idea of using a tie-breaker referee when two referees disagree.) In fact, only the top-2p papers have a conditional probability of rejection that is less than 50%, resulting in a majority rejection probability that does not increase with the number of referees.

Fighting celebrity paparazzi using economics

Many celebrities seem to live like caged animals because they're beset by paparazzi whenever they leave their home.

Why not adopt the following supply-side solution to this problem?

My idea is that Brad Pitt and Angelina Jolie should hire a full-time photographer who follows them around whenever they leave the house and takes tons of photographs of them. They would then flood the market with these photographs, selling them to celebrity-gawking magazines for next to nothing, far undercutting the price that regular paparazzi charge these magazines. Because the private photographer would have better access than the regular paparazzi, the photos will be of higher quality and lower price, making them irresistible to the magazines. Now that the regular paparazzi can't make a living off of stalking Pitt and Jolie, they'll stop, and the couple can live in relative peace.

The monetary cost of maintaining a full-time photographer should be trivial to major celebrities. These celebrities are probably also used to having employed housestaff around all the time, so it's no big deal to have another one around. You would have to disseminate many private and somewhat unflattering moments, but that's already happening in the current equilibrium. (If no unflattering pictures were voluntarily disseminated, then you leave an opening for an outside paparazzo who specializes in capturing such shots to profitably remain in the market.) By becoming the low-cost provider in this market, the celebrity can prevent the really unflattering images from leaking out and avoid the unpleasant experience of being hounded by paparazzi stalkers. The total quantity of published photographic disclosure probably wouldn't increase that much, but the personal burden of that disclosure would decrease dramatically.

Brad and Angelina, you're welcome.
--A rare original post by the author of this blog

Even the car accidents are bigger in Texas


Two people died and more than 80 people were hurt Thursday when at least 100 vehicles collided in Southeast Texas in a pileup that left trucks twisted on top of each other and authorities rushing to pull survivors from the wreckage.

The collision occurred in extremely foggy conditions at about 8:45 a.m. Thanksgiving Day on Interstate 10 southwest of Beaumont, a Gulf Coast city about 80 miles east of Houston. ...

According to DPS, a crash on the eastbound side of the highway led to other accidents in a dangerous chain reaction. There were multiple crashes on the other side of the highway as well. ...

I-10's eastbound lanes were re-opened Thursday evening after more than eight hours.

An unintended consequence of electronic medical records

A few years ago, we doctors kept handwritten charts about patients. Back then, it sometimes seemed like we spent half our time walking around looking for misplaced charts, and the other half trying to decipher the handwriting when we found them. The upside was that if I did have the chart in front of me, and I saw that someone had taken the trouble to write something down, I believed it.

Unfortunately, this is no longer the case. The advent of electronic medical records has been a boon to patient safety and physician efficiency in many ways. But it has also brought with it a slew of “timesaving” tricks that have had some unintended consequences. These tricks make it so easy for doctors to document the results of standard exams and conversations with patients that it appears more and more of them are being documented without ever having happened in the first place.

For instance, doctors used to have to fill out a checklist for every step in a physical exam. Now, they can click one button that automatically places a comprehensive normal physical exam in the record. ...

Hospitals received $1 billion more from Medicare in 2010 than they did in 2005. They say this is largely because electronic medical records have made it easier for doctors to document and be reimbursed for the real work that they do. That’s probably true to an extent. But I bet a lot of doctors have succumbed to the temptation of the click. Medicare thinks so too. This fall, the attorney general and secretary of health and human services warned the five major hospital associations that this kind of abuse would not be tolerated.

And then there are the evil twins, copy and paste. I’ve seen “patient is on day two of antibiotics” appear for five days in a row on one chart. Worse, I’ve seen my own assessments of a patient’s health appear in another doctor’s notes. A 2009 study found that 90 percent of physicians reported copying and pasting when writing daily notes.

In short, reading the electronic chart has become a game of looking for a small needle of new information in a haystack of falsely comprehensive documentation and outdated, copied text. Why do we doctors do this to ourselves? Largely, it turns out, for the same reason most people do most things: money.

Doctors are paid not by how much time they spend with patients, how well they listen or how hard they think about what could be wrong, but by how much they write down. And the rules for what we have to write are Byzantine: Medicare’s explanation takes 87 pages.
--Leora Horwitz, NYT, on a result of lowering the cost of supplying medical documentation

Sunday, November 18, 2012

The struggle of writing

Writing is frustration — it’s daily frustration, not to mention humiliation. It’s just like baseball: you fail two-thirds of the time. I can’t face any more days when I write five pages and throw them away. I can’t do that anymore.
--Philip Roth on why he's retiring

Monday, November 5, 2012

Is corruption all that bad for economic growth?

To be clear, my point wasn’t that corruption is unimportant. But if we’re talking about where the world ought to focus its aid energy for the next fifteen years, I simply wouldn’t use corruption in the same sentence (or even paragraph) as civil war or property rights. ...

The reasons that corruption should hurt growth are so persuasive that economists have been pretty surprised not to find much evidence. One team reviewed 41 different cross-country studies of corruption and development. Two-thirds of the studies don’t even find a negative correlation. Cross-country studies have mostly bad data and empirics, so we should not rest here. But Jacob Svensson has a nice overview of the broader evidence and draws the same conclusion: there’s not much to show that corruption reduces growth on net. ...

Are we any good at stopping corruption? Svensson and Bardhan see some hope, but not many good answers. In this article, Rohini Pande’s more hopeful, especially if we design policy armed with economic theory and experiment. ...

[Pritchett, Woolcock, and Andrews] run the following thought experiment: What if we tried to measure the quality of governance (including corruption) over time and space, and figure out the 20 fastest improvements countries have made in recorded history? Then, using this best-case-scenario, we ask how long it will take today’s poorest and weakest states just to get to the median level of governance–not to the level of a Canada or Sweden, but to the (decidedly less ambitious) level of a Tanzania or Guatemala. The answer, depending on the country, is 15 to 35 years. And that’s if they experience a miracle of change.

The goal the US and UK commonly set for the Afghanistans and Liberias of the world, of course, is about three to five years. Just witness the public and political angst every time the NY Times uncovers corruption in its Afghan regime. Be prepared for more.

If this saddens you, just remember the first half of my post: it probably doesn’t matter much, and outsiders should probably be putting their attention elsewhere.

Companies respond to incentives: Health insurance edition

Some low-wage employers are moving toward hiring part-time workers instead of full-time ones to mitigate the health-care overhaul's requirement that large companies provide health insurance for full-time workers or pay a fee.

Several restaurants, hotels and retailers have started or are preparing to limit schedules of hourly workers to below 30 hours a week. That is the threshold at which large employers in 2014 would have to offer workers a minimum level of insurance or pay a penalty starting at $2,000 for each worker.

The shift is one of the first significant steps by employers to avoid requirements under the health-care law, and whether the trend continues hinges on Tuesday's election results. ...

Pillar Hotels & Resorts this summer began to focus more on hiring part-time workers among its 5,500 employees, after the Supreme Court upheld the health-care overhaul, said Chief Executive Chris Russell. The company has 210 franchise hotels, under the Sheraton, Fairfield Inns, Hampton Inns and Holiday Inns brands. ...

CKE Restaurants Inc., parent of the Carl's Jr. and Hardee's burger chains, began two months ago to hire part-time workers to replace full-time employees who left, said Andy Puzder, CEO of the Carpinteria, Calif., company. ...

Home retailer Anna's Linens Inc. is considering cutting hours for some full-time employees to avoid the insurance mandate if the health-care law isn't repealed, said CEO Alan Gladstone. ...

In a July survey, 32% of retail and hospitality company respondents told the consulting firm [Mercer] that they were likely to reduce the number of employees working 30 hours a week or more.
--Julie Jargon, Louise Radnofsky, and Alexandra Berzon, WSJ, on how a tax on full-time work reduces full-time work

Thursday, November 1, 2012

The MacGyver-like powers of dental floss

In Texas, officials believe a prisoner used floss to cut his way out of his cell, then jumped a fellow inmate and knifed him to death.

In Maryland, Illinois, West Virginia and Wisconsin, inmates collected enough floss to braid it into ropes and escape, or try to, over prison walls.

A group of escaped prisoners on the run in Texas used floss to sew up their gunshot wounds.

And a man in an Illinois jail used floss to stitch together the dummy he left in his bed when he took off.

Experts say floss, or the plastic holder it sometimes comes in, has been used to strangle enemies, to escape, to saw through bars, to pick handcuffs, to make a hand grip on a shank and to hoist contraband from one level of cells to another. ...

An episode of the science TV show "Mythbusters" a few years ago set up an experiment to challenge the floss-as-security-risk theory. The show used a floss-equipped robot to test whether floss — combined with toothpaste to make it more abrasive — could really saw through a bar on a jail cell.

The feat was declared "plausible," given 300 days at eight hours a day — the kind of time that an inmate might have. ...

It was waxed floss that was used in Wisconsin in 1997 by inmates Timothy Dummer and Guy Dunwald. They used ropes of braided floss to get over a wall at the Green Bay Correctional Institution. They were quickly recaptured and had five years added to their sentences.

A television story about the episode said the prisoners had collected 18,975 feet — more than 3½ miles — of dental floss.
--Jim Fitzgerald, Associated Press, on the potent combination of persistence, ingenuity, and dental floss. HT: Marginal Revolution

Christopher Nolan's Star Wars Episode VII

But a Christopher Nolan Star Wars would be terrible. There’s simply no bridging the brooding, cerebral mind of Christopher Nolan with the goofy, fantastical universe of that galaxy far, far away. ...

Take just a minute to “imagine the greatness” we could expect from Star Wars Episode 7: The Dark Jedi Knight. Struggling with the mysterious loss of his wife Mara Jade (played in flashback by Marion Cotillard), a middle-aged Luke Skywalker (Christian Bale) has found himself in a pained exile back on Tatooine. We gradually piece together that after losing an internal struggle with his anger, hate, and suffering, Skywalker was labeled a potential Sith by the Jedi Council, and thrown out by the terrorist and corporate businessman Jacen Solo. This all leads to a series of disorienting lightsaber battles and spaceship chases (mandated by Disney, and carried out half-heartedly by Nolan), culminating in a startling revelation: As the brass in Hans Zimmer’s score swells, we learn that it was Skywalker who accidentally sabered Mara Jade; he then used a Jedi Mind Trick on himself to wipe the memory. As Skywalker must decide whether to keep this memory—his only hope for channeling enough of the Dark Side to beat Jacen Solo—we cut to black.
--Forrest Wickman, Slate, on the case against Christopher Nolan taking over Star Wars

Stop donating canned goods

America, after all, is not a country stricken with famine. There’s no objective shortage of food, in other words, that makes it vitally important for you to draw down the stockpile in your kitchen cabinet. Indeed, many of us don’t even have that much food socked away, which leads to us going out to buy extra food in order to give it away. But having 100 different people go out and pay retail prices for a few cans of green beans is extraordinarily inefficient relative to pooling those funds to buy the beans in bulk.

But it’s even worse than that. All across America, charitable organizations and the food industry have set up mechanisms through which emergency food providers can get their hands on surplus food for a nominal handling charge. Katherina Rosqueta, executive director of the Center for High Impact Philanthropy at the University of Pennsylvania, explains that food providers can get what they need for “pennies on the dollar.” She estimates that they pay about 10 cents a pound for food that would cost you $2 per pound retail. You’d be doing dramatically more good, in basic dollars and cents terms, by eating that tuna yourself and forking over a check for half the price of a single can of Chicken of the Sea.

Beyond the economies of scale are the overhead costs. Charities are naturally reluctant to turn down donations for fear of alienating supporters or demoralizing well-wishers, but the reality is that dealing with sporadic surges of cans is a logistical headache. A nationwide network of food banks called Feeding America gingerly notes on its website that “a hastily organized local food drive can actually put more strain on your local food bank than you imagine.” Food dropped off by well-meaning citizens needs to be carefully inspected and sorted. A personal check, by contrast, can be used to order what’s needed without placing extra burdens on the staff.

A lot of waste also occurs on the other side of the food-donation equation. Rosqueta observes that a surprisingly large proportion of food—as much as 50 percent—provided to needy families in basic boxes winds up going uneaten. ... Social service providers know their clients better and, with cash in hand, can pull together items people are likely to want and let them pick what they need, cutting down on waste.
--Matthew Yglesias, Slate, on why you should just write a check