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Archive for 2011

Porn and Rape: The Debate Continues

The question of whether the rise of Internet pornography has reduced incidents of rape is nothing new, and something we’ve covered before. Back in 2006, Levitt expressed skepticism over research done by one of his former students that suggests a link, writing at the time:

The kind of variation in the data that gives the result is that states that are quicker to adopt the internet saw bigger declines in rape. He then does a nice thing in the paper, going beyond just this one prediction to test other hypotheses, like do crimes other than rape fall with the internet (he says no) and does other sexual behavior change with the internet (he says yes). The concern is always, with this kind of approach, that there are other factors that might be driving both the adoption of the internet and the decline in rape. The challenge to those who want to refute Todd Kendall’s argument is to identify those variables. The challenge for Todd is to find other kinds of “natural experiments” that support his hypothesis.

Now comes an article in the current issue of Scientific American Mind, which posits that for “most people, pornography has no negative effects—and it may even deter sexual violence.” The article, titled “The Sunny Side of Smut,” is by Melinda Wenner Moyer, a science writer. Here’s a full version of the piece, via Moyer’s website. Though an interesting read, the article adds no new empirical evidence to the subject, and relies heavily on the data showing that rape decreased faster in states that got the Internet quicker. As Levitt pointed out, that’s not enough to go on.


Is it Really Darkest Just Before the Dawn?

I’m back to inviting readers to submit quotations whose origins they want me to try to trace, using my book, The Yale Book of Quotations, and my more recent researches.
Georgia asked:

“where does the saying ‘the world is your oyster’ come from?”

According to the Oxford English Dictionary, this is an allusion to “the possibility of finding a pearl in an oyster” and means “one is in a position to profit from the opportunities that life, or a particular situation, may offer.” The earliest citation for the expression given by the OED is from Shakespeare’s Merry Wives of Windsor: “Why then the world’s mine Oyster, which I, with sword will open.”
Josh asked:

“I always get annoyed by people who say, ‘It’s always darkest just before the dawn,’ usually said to cheer somebody up who’s down on their luck with hope of better times. I’d prefer people either offer a unique thought or something that makes scientific sense. Where did this horrible quote come from?”


Are We Actually Getting Better at Chess?

How do you tell if we’re getting better at a sport or a game, when you can never pit players from different eras against each other? For example, could Tom Brady carve up Pittsburgh’s Steel Curtain defense of the 1970s? Who would win one-on-one, Michael Jordan (in his prime) or LeBron James? Could Justin Verlander strike out Babe Ruth? Outside of video games, we’ll never know.
The obvious exceptions are track and field events, where accomplishments are measured in time and distance. And in those cases, we actually have been consistently chipping away at records, running faster, jumping higher etc. Though the recent use of performance-enhancing drugs has certainly tainted that “progress.”
But what about chess? Players are judged by a sophisticated rating system, though there’s a thought that scores have been inflated recently. A pair of academics have set out to address this by comparing the quality of play over the years. In their recent paper, Kenneth W. Regan, a computer science professor at the University of Buffalo, and Guy Haworth, an engineering professor at the University of Reading, examine the quality of players’ moves, rather than win-or-lose outcomes. Their conclusion is that yes, we are getting better at chess.


The Case for Biofortification

Modern consumers enjoy something that humans throughout history never have: we can walk into a grocery store and, if we choose wisely, leave with food that maximizes our health. Much maligned as the industrial food system has been, it’s made accessible a broad diversity of beneficial foods that, consumed regularly, prevent disease and enhance the quality of life. The fact that one is able to eat a cornucopia of “superfoods”–blueberries, bananas, kale, lentils, quinoa, and avocados–on a daily basis is an under-appreciated wonder of globalization and world trade.
But the vast majority of the developing world lacks access to this abundance. In fact, billions of people living in developing countries are dependent on a single staple crop for their sustenance. In sub-Saharan Africa, 250 million people eat cassava as their primary food source; over half the world depends on rice for 80% of their calories; wheat accounts for 20% of the world’s food energy intake. This narrow dependence might meet baseline caloric needs, but it’s a nutritional disaster.
How to bridge the gap between the nutritional haves and have-nots is a hotly contested issue. Some support the development of small-scale but modernized organic systems serving regional markets. Others promote replacing traditional peasant agriculture with the industrialized approach of agribusiness. Yet others would like to see local farmers empowered to practice indigenous methods. Whichever schemes ultimately prevail (hopefully a combination of all), there’s one solution that must be included irrespective of agricultural scale or scope: crops must be biofortified. That is, we need to plant seeds that have been bred to enhance nutritional value.


Innovations in Restaurant Tipping: Just Do the Math For Us

At a local cafe in western Massachusetts the printed bill contains something I’ve never seen before: At the bottom is a list of percentages—15, 18 and 20—with suggested gratuity amounts based specifically on the bill’s total. While tipping is a social norm in the U.S., it’s a hassle to figure out the right amount to tip. The tip amount is rarely suggested, and never in specific dollar terms (though sometimes a gratuity is included for larger groups of diners).
So why not do this everywhere? Perhaps it could be viewed as crass; but it saves time and makes the social norm explicit (as it already is in our minimum wage laws)—and it might shame those who refuse to tip. I hope this innovation spreads rapidly in this time of apparently decreasing social cohesion.


Dick Gregory and the Old Reverse-Incentive Trick

We’ve blogged a few times about the clever use of what you might call reverse incentives — that is, turning someone else’s unwelcome behavior into a positive outcome for yourself. Planned Parenthood turned abortion protestors into a fund-raising scheme; a comedian used this same “pledge-a-picket” tactic against the Westboro Baptist Church.
I recently ran across an older example, from the groundbreaking comedian and activist Dick Gregory, probably still best known for his autobiography, called Nigger.
The book was co-written by Robert Lipsyte, a longtime Times sports-and-culture columnist whom I interviewed recently for an upcoming podcast about booing. In Lipsyte’s rousing, fascinating new memoir, An Accidental Sportswriter, he writes about his collaboration with Gregory (whom he calls Greg), and the latter’s shrewd understanding of human nature, incentives, and hatred. Excerpts:


Why Do Black Men Live Longer in Prison?

A recent Reuters headline got a lot of attention on the Web. It read: “Black men survive longer in prison than out: study.” Gawker picked it up; so did The Atlantic, Yahoo, and the Grio. I tracked down the study’s author David Rosen, an epidemiology PhD and a post-doctoral fellow at the University of North Carolina, to see if this was actually the case. Rosen focuses his research on the health-care system inside prisons. For this latest study, he matched North Carolina prison records against state death records from 1995 to 2005, in order to compare the mortality rates of black and white male prisoners against their general population counterparts.
The results of his sample (100,000 men aged 20-79) were striking in how much they differed by race. While the total death rate of black men in prison is half that of black men in the general population, white prisoners die at about a 12% faster clip than their general population counterparts. This is essentially what a previous report by the U.S. Bureau of Justice Statistics found in 2007.
Rosen was good enough to answer questions about what he feels his study says about health-care, prisons and race.


Our Daily Bleg: How Should a Professor Incentivize Classroom Attendance?

Art Wright, a professor*, writes in to say:

I have this problem: I am course-planning for the fall term right now, and I’m trying to figure out the best way to develop an attendance policy. Many professors deduct points or letter grades for a certain number of absences. In contrast, I had someone recommend that I give points if students come to most or all of the class meetings. So I’m left wondering: What is the best way to incentivize class attendance for my students? What, in your opinion, will get them to attend most – if not all — of the class meetings?

What advice do you have for Art?
If you’re a professor, let us know what you’ve tried that has worked or failed. If you’re a student or used to be one (I assume that means everyone here), what did it take to get you to show up regularly?
*By the way, Art is a visiting professor of New Testament at the Baptist Theological Seminary at Richmond. Am wondering how readers might answer (or engage with) his question differently if I’d introduced him as such rather than simply as a “professor.” Of all the assumptions we make and biases we carry, it strikes me that religion encourages some of the strongest ones.


How Biased Is the Media? Bring Your Questions for the Author of Left Turn

Tim Groseclose is a political-science professor at UCLA (and an occasional co-author with Steve Levitt) who has spent years trying to systematically and empirically study media bias. He has a new book out called Left Turn: How Liberal Media Bias Distorts the American Mind. Here’s what Levitt had to say about it recently:

As the title suggests, it has a definite conservative slant. It is not, however, a right-wing rant by any means. Rather, it is a carefully researched and amusingly written book by a highly regarded academic.

Groseclose’s core argument is that the U.S. media overall has a strong liberal bias, and that this bias strongly influences how Americans vote and how they think about the issues of the day. He reached this conclusion by constructing a “political quotient” (PQ), which is meant to measure political views in a “precise, objective, and quantitative way.” The average American voter, he argues, has a PQ of 50. Liberal Democrats Barney Frank and Nancy Pelosi both have a PQ of approximately 100; conservative Republicans Michele Bachmann and Jim DeMint have a PQ of approximately 0. If we could “magically eliminate liberal media bias,” Groseclose writes, the average American would have a PQ closer to 25, and would be more in line with people like Ben Stein, Dennis Miller and Bill O’Reilly.


What Does Your Web Browser Say About Your I.Q.? (Hint: I.E. Users Won't Like the Answer)

See ADDENDUM (8-3-11; 9:13am EDT) below
A study by AptiQuant Psychometric Consulting finds that people who use Internet Explorer as their web browser are, on average, less smart than those who use other browers. As PC Mag reports:

Over a period of around four weeks, the company gave a Wechsler Adult Intelligence Scale (WAIS) to users looking for free online IQ assessment tests, then recorded the results and browsers used for all participants above the age of 16.
Across the board, the average IQ scores presented for users of Internet Explorer versions 6 through 9 were all lower than the IQ scores recorded for Firefox, Chrome, Safari, Camino, and Opera users.


The Economic Reasoning of "Ultimogeniture" of Amish Farms

My younger son’s family visited the nearby Amish country and did a tour of several farms. The guide mentioned that the youngest son usually takes over the farm from his father. The older brothers typically learn trades. She thought this happens because the father isn’t ready to give up the farm when the older brothers reach adulthood.
My economic explanation is that this minimizes the frequency of paying estate taxes (no longer a very binding constraint, but it was until quite recently). Perhaps this “ultimogeniture” is an illustration of an unusual excess burden generated by estate taxes. Or perhaps there’s another explanation? (Related: check out Freakonomics Radio on “The Church of ‘Scionology.'”)


How Best to Realign Major League Baseball: A Freakonomics Quorum

Earlier this summer, ESPN’s Buster Olney reported that Major League Baseball and the players’ association had recently discussed a form of realignment that would result in two leagues of 15 teams, rather than the current structure of 14 teams in the American League, and 16 in the National League. This sent the sports world into a tizzy as baseball geeks everywhere weighed in on how best to realign MLB. There are a lot of ideas out there: shorten the season so each team gets one day off a week (said to be a favored position of Commissioner Bud Selig), move the Houston Astros or Florida Marlins to the American League; create three divisions of five teams each; do away with the divisions entirely; add an extra wild-card team to expand the playoffs.
There’s also a discussion about finding ways to address the disparity in miles traveled. According to this neat interactive graphic put together by Paul Robbins at the New York Times, in 2009, the Dodgers traveled a league-high 59,742 miles, while the Nationals traveled less than half that, 26,266 miles.
Not to be left out, we decided it was a good time to convene a Freakonomics Quorum. We rounded up a handful of sports economists and asked them the following question:

What proposed realignment changes seem to make the most sense from a competitive and economic standpoint for Major League Baseball?


Mobility in the U.S. is Down. What's More of a Factor: the Housing Slump, or Air-Conditioning?

It’s always been one of the supposed strengths of the American economy: the relative ease with which we’re able to pick up and move. This is particularly useful when times are tough and you need to unhinge from a weak local economy. The thing is, mobility tends to sag during economic downturns. The entire 1930s marked a period of relatively low internal migration, just as the booming post-war decades saw a significant rise.
The conventional wisdom today is that mobility is being dragged down by the housing crisis, that people underwater on their mortgage or reluctant to sell their home into a soft market are choosing to stay put.
But a new study from Notre Dame economist Abigail Wozniak, along with two colleagues at the Federal Reserve, Raven Molloy and Christopher L. Smith, throws some water on that theory by showing that states with high percentages of homeowners with negative equity are no more likely than other states to see a decline in long-distance migration of their residents.


Wanted: Boston and Philadelphia Travel Tips

The boy is entering fifth-grade, which concentrates on American history (finally!). And so we are road-tripping to Boston and then Philadelphia to see what we can see. As you all have given me fantastic advice re Vegas, D.C., and Beijing, I turn to you once again for tips about things to see, do, eat, avoid, and celebrate in these two wonderful American cities. All advice appreciated; no ideas too absurd (or commonplace). I’ll send some swag to whoever supplies the most valuable tip in each city. Thanks!


Surprise, Surprise: The Future Remains Hard to Predict

“There is a huge discrepancy between the data and the forecasts.”
In what realm do you think this “huge discrepancy” exists? The financial markets? Politics? Pharmaceutical research?
Given how bad humans are at predicting the future, this discrepancy could exist just about anywhere. But the above quote, from the University of Alabama-Huntsville climate scientist Roy Spencer, is talking about computer models that predict global warming:


An Economist's Twitter Experiment Begins

I promised to give Twitter a real randomized trial. And so today, it begins. I woke up, flipped a coin, and it came up heads. Which means that today I’ll be tweeting. You can follow me @justinwolfers. What I do tomorrow is up to the coin.
I announced this experiment here three weeks ago, but wanted to spend some time getting used to this new medium. Here are eleven things I learned during my pre-experiment trial:
1. Twitter is fun. And addictive.
2. Information really does move at light speed. I find myself reading tomorrow’s newspaper, today. (But remember: tomorrow’s newspaper will be here in the morning.)
3. As a Twitter-virgin, I hadn’t previously realized how much more it is about sharing links than making glib statements. Hive-mind curation can be extraordinary.


Killer Cars: An Extra 1,000 Pounds Increases Crash Fatalities by 47%

Ever since the SUV craze began in the late 1980s, we’ve all known that heavier vehicles are safer for those driving them, but more dangerous for others on the road. Which is why we all started driving them. Now, in a new working paper, a pair of Berkeley economists have quantified not only the fatality risks of heavier cars for other drivers, but also the costs associated with them. Here’s the abstract:

Heavier vehicles are safer for their own occupants but more hazardous for the occupants of other vehicles. In this paper we estimate the increased probability of fatalities from being hit by a heavier vehicle in a collision. We show that, controlling for own-vehicle weight, being hit by a vehicle that is 1,000 pounds heavier results in a 47% increase in the baseline fatality probability. Estimation results further suggest that the fatality risk is even higher if the striking vehicle is a light truck (SUV, pickup truck, or minivan). We calculate that the value of the external risk generated by the gain in fleet weight since 1989 is approximately 27 cents per gallon of gasoline. We further calculate that the total fatality externality is roughly equivalent to a gas tax of $1.08 per gallon. We consider two policy options for internalizing this external cost: a gas tax and an optimal weight varying mileage tax. Comparing these options, we find that the cost is similar for most vehicles.


Inmates Cash in on Prison Phone Glitch

From Arelis R. Hernández at the Orlando Sentinel comes a hilariously idiotic story of a jail in Lake County, Florida, where rather than having money withdrawn from their accounts, inmates were paid to make phone calls. So much so that one man bonded out after making 77 calls and having $1,250 deposited into his account. He ended up turning himself in a few hours later.


FREAK-est Links

Georgia’s shriveling peach economy, one-third of Michigan teachers feel pressured to cheat, the annual Big Mac index, a public library incentive scheme, and why West Virginia is awash in car crashes the week after a televised NASCAR race.


A Scuffle over "Scuffle"

I’m back to inviting readers to submit quotations whose origins they want me to try to trace, using my book, The Yale Book of Quotations, and my more recent researches.
Jim asked:

This is a little different and may not really be possible to trace but…
For whatever reason, I am very irritated by the constant use of the world ‘scuffling’ to mean ‘struggling’ — as in having a hard time — by sportswriters and TV sportscasters and analysts (i.e., ‘Ever since his concussion, Justin Morneau has been really scuffling at the plate’). I was heartened to see that this New York Times article was reprinted with ‘struggling’ in place of ‘scuffling’ (see note at the bottom of the page).
I think of ‘scuffling’ in the context of fighting or struggling physically, not struggling in terms of performance in a sport or in a job, what have you. Do you agree that ‘scuffling’ in this context is misused? And, can you trace the beginnings of this mis-usage? I realize this is slightly different than what’s usually asked here but thank you.


Minority Rules: Why 10 Percent is All You Need

What does it take for an idea to spread from one to many? For a minority opinion to become the majority belief? According to a new study by scientists at the Rensselaer Polytechnic Institute, the answer is 10%. Once 10% of a population is committed to an idea, it’s inevitable that it will eventually become the prevailing opinion of the entire group. The key is to remain committed.
The research was done by scientists at RPI’s Social Cognitive Networks Academic Research Center (SCNARC), and published in the journal Physical Review E. Here’s the abstract:

We show how the prevailing majority opinion in a population can be rapidly reversed by a small fraction p of randomly distributed committed agents who consistently proselytize the opposing opinion and are immune to influence. Specifically, we show that when the committed fraction grows beyond a critical value pc=10%, there is a dramatic decrease in the time Tc taken for the entire population to adopt the committed opinion. In particular, for complete graphs we show that when p<pc, Tc~exp[a(p)N], whereas for p>pc, Tc~lnN. We conclude with simulation results for Erdos-Rényi random graphs and scale-free networks which show qualitatively similar behavior.


A Lesson in Free Vitamins

A friend mentioned an interesting way that the Internet can reduce cost, raise output, and that uses incentives cleverly. Her company created an educational ad campaign to encourage young women to engage in healthy activities. On several occasions various unrelated blogs mentioned that free vitamins were being given through the campaign’s website linked to the ads. Using Google Analytics she discovered that the website’s hits went up over tenfold after each mention on the blogs; but the data also showed that most of the new hits were by people who got onto the website just long enough to get the freebies.
In the next round the offers will be restructured so the freebies are available only after the person has watched an online educational video—and thus imbibed the health-promoting knowledge that was the purpose of the campaign.
[HT: CS]


Lottery Tickets for Safe Drivers?

Last month, Eric Morris wrote a post on red light cameras at traffic intersections in L.A. that sparked a robust debate in the comments section, something we always like. The debate centered around whether these devices are effective at reducing people’s willingness to run a red light, or whether they’re merely sources of revenue for the city. Perhaps you’ll feel similarly passionate about a new Australian study that examined the benefits of fixed speed cameras in New South Wales. From an ABC.net.au article:

On the whole [Auditor-General Peter Achterstraat] has found that speed cameras do change driver behavior and improve road safety but not in all cases. He has found 38 of the 141 fixed cameras across the state seem to have no significant benefit to road safety.


Culture-Bound Syndromes Run Amok

A recent Slate article by Jesse Bering outlines the strange and true world of culture-bound syndromes — mental illnesses that occur in certain geo-specific populations or “sociocultural milieus.” Perhaps the most famous is “amok,” the root of “run amok,” and a problem in Malaysia, Polynesia, Puerto Rico and the Navajo Nation. The syndrome affects males 20–45, who become homicidally violent after a perceived insult. After which, of course, the subject remembers very little. Sound like a good cover? It gets weirder.
In China, we find Koro: “in which the patient is convinced that protruding bodily organs, such as the male genitalia or female nipples, are retracting or disappearing into his or her body.” Koro, however, has a habit of jumping all over the globe, and has been well documented in Thailand, India and Africa. Koro’s internationalism, like that of other culture-bound diseases, throws the specificity of “culture” into question, and the genre of these illnesses remains murky, nearly impossible to define, and fertile ground for wild postulating. Mythology in particular permeates the “culture-bound” discussion. Perhaps it is the particular oral traditions of a people who jump beyond the campfire into the lives – and bodies – of their listeners.
And as for what America has to add? Muscle dysmorphia!


Blind to Our Own Blindness: Wisdom from Danny Kahneman

I recently had the chance to read an advance copy of an outstanding book by Daniel Kahneman entitled Thinking, Fast and Slow. The book will be published this fall.
Among the hundreds of interesting ideas in the book, there is one that I simply can’t get out of my head. Referring to how our minds work, Kahneman writes that not only are we sometimes “blind to the obvious,” but also we are “blind to our blindness.” For me, that one sentence summarizes a fundamental insight of his life’s work.
It’s one of those simple insights which is obvious when you think about it, but somehow incredibly easy to forget when mesmerized by the happenings of everyday life, leading to poor decision making.
Coming up with a good name for a problem is often an important part of coming up with a solution. So I’m thankful to Kahneman for planting the phrase “blind to my own blindness” in my brain. The next time I’m about to mindlessly make a terrible choice, I’m hoping that phrase will forcefully interject itself into my internal dialogue, causing me to think more clearly about my decision.
More likely, it will only be after the fact that I become aware that I was blind to my own blindness in a particular setting. At least I’ll have a succinct way of beating myself up.


Backyard Hens: A Trend Coming Home to Roost?

The infamous egg recall of 2010–which identified over 500,000 eggs infected with salmonella–inspired not only widespread condemnation of industrial egg production, but a reactionary upsurge in the trend of keeping backyard hens. For reasons that seem intuitively straightforward (but lack concrete substantiation), a critical mass of do-it-yourselfers determined that it was, among other benefits, safer and more humane to raise their “own” birds and eat their “own” eggs. As this movement continues to take shape, it’s worth asking if these evaluations are all they’re cracked up to be.
As for safety, we’ve really no way of knowing at this point. To the best of my knowledge (and please, if I am wrong, show me), nobody has calculated comparative rates of infection between backyard and industrialized birds. What we do know is that backyard chickens aren’t immune to disease outbreaks. Just last month Food Safety News reported that the CDC had identified 71 cases of salmonella (more than half under the age of 5) linked to backyard chickens. Eighteen people were hospitalized.


The Economic Value of (Very) Personal Data

Graphic designer Nicholas Felton keeps track of how many miles he walks each day. He also records how many book pages he reads, how many work e-mails he sends, and what songs he listens to. Felton’s become somewhat famous for his obsessive self-tracking, and the slick info-graphics he produces on himself each year. Both the Wall Street Journal and Slate have made videos about him, here and here.
Felton began tracking his daily habits and compiling a Personal Annual Report in 2005, available at his website.


Will U.S. Shale Gas Rebalance Global Politics?

Fascinating article from the Houston Chronicle:

The natural gas boom in the U.S. has weakened Russia’s influence on European energy supplies and could keep Iran’s influence in check for years to come, according to a new study from the Baker Institute for Public Policy at Rice University.

The study, “Shale Gas and U.S. National Security,” says the surge of drilling in shale formations will have an impact on global supply for years to come and limit the need for the U.S. to import liquefied natural gas, or LNG, for at least 20 to 30 years.

That means more LNG shipments from the Middle East will be available for Europe, which has been beholden to Russia for a large portion of its gas, supplied by pipelines.

The study, funded by the U.S. Department of Energy, predicts that Russia’s share of the natural-gas market in Western Europe will drop to as little as 13 percent by 2040, down from 27 percent in 2009.


In New York City, It Still Pays to Hop the Subway Turnstile

A report by New York City’s Metropolitan Transportation Authority seems to prove that hopping a subway turnstile is worth the risk of getting caught and fined. The MTA estimates that riders entered the subway without paying 18.5 million times in 2009 (an average of 50,684 a day) while the police issued just 120,000 summonses, or 1 for every 154 jumps.
The report figures that a regular turnstile jumper has a chance of getting caught only once every 6 to 13 weeks. At $100 per fine, this works out to be cheaper than a $27 weekly unlimited Metrocard that would cost $162 over six weeks. So the fare-skipper who gets nabbed only once in that period still comes out ahead by $62. And that was in 2009. While the price for a weekly pass has since increased to $29, the cost of the fine has not, so in 2011 it pays even more to hop the turnstile.
From the Daily News:

“This basic street economics might explain observed evasion behaviors,” the authors of the report wrote, arguing stiffer penalties might cut down on scofflaws. “Higher fines or arrests may have better deterrent effects.”