How Do Real Prisoners Play Prisoner's Dilemma?

Economists Menusch Khadjavi and Andreas Lange recently published a paper on how real prisoners play the Prisoner's Dilemma game:

We report insights into the behavior of prisoners in dilemma situations that so famously carry their name. We compare female inmates and students in a simultaneous and a sequential Prisoner's Dilemma. In the simultaneous Prisoner's Dilemma, the cooperation rate among inmates exceeds the rate of cooperating students. Relative to the simultaneous dilemma, cooperation among first-movers in the sequential Prisoner's Dilemma increases for students, but not for inmates. Students and inmates behave identically as second movers. Hence, we find a similar and significant fraction of inmates and students to hold social preferences.

(HT: Marginal Revolution)

Can Geography Be Radical?

Guernica recently interviewed "radical geographer" Denis Wood about his work and the power of map (a topic we've touched on before). Here's a particularly interesting excerpt:

But I’ve seen maps that I find completely terrifying. Maps of uranium mining and of various illnesses in the Navajo reservations—they’re just insane. They just make you furious. Bill Bunge’s map—which I still think is one of the great maps, the map of where white commuters in Detroit killed black children while going home from work—that’s a terrifying map, and that’s an amazing map. He knew that. They had to fight to get the data from the city. They had to use political pressure to get the time and the exact location of the accidents that killed these kids. They knew what they were looking for. I didn’t have anything to do with that project, so when I saw the map for the first time, it was like, “Oh my god.” It’s so powerful to see maps like that. That’s the power of maps, or one of the powers of maps: to make graphic—and at some level unarguable—some correlative truth. We all knew that people go to and from work. But to lay the two things together reveals something horrible.

(HT: The Daily Dish)

The Economics of Higher Education, Part 4: Worldwide Returns on College

We've discussed before -- in blog posts and a podcast -- the value of a college degree. Writing for the New York Times Economix blog, Catherine Rampell points out that college degrees are particularly valuable in the U.S. "According to a report released this week by the Organization for Economic Cooperation and Development, across the developed world the average person who has graduated from college (either two-year or four-year) and has any earnings makes about 57 percent more than a counterpart with no more than a high school education," writes Rampell. "In the United States, the comparable earnings premium is 77 percent."  

Despite the value of a college degree in the U.S., college graduation rates in the U.S. are increasing at a much slower pace than in other rich countries.  And, as Rampell points out, it's not just individuals in the U.S. that benefit from a college degree: "[T]he average return to taxpayers [of tertiary education for the average man] is $230,722 in the United States, versus less than half that, $104,737, across the developed world." 

For more on "The Economics of Higher Education," see Part 1, Part 2, and Part 3.

Also: Oregon is thinking about letting students pay no college tuition, instead pledging a share of their future earnings. Lest you think this is straight out of Portlandia (like this is), know that Australia runs a similar college-tuition program

Further Evidence That Wine Tasting Is Wildly Subjective

A few years ago, we did a podcast on whether expensive wine tastes better. There is now further evidence that the answer to that question is no -- even for elite wine critics. Winemaker Robert Hodgson recently collaborated with the California State Fair wine competition on a little wine-tasting experiment:

Each panel of four judges would be presented with their usual "flight" of samples to sniff, sip and slurp. But some wines would be presented to the panel three times, poured from the same bottle each time. The results would be compiled and analysed to see whether wine testing really is scientific.

The first experiment took place in 2005. The last was in Sacramento earlier this month. Hodgson's findings have stunned the wine industry. Over the years he has shown again and again that even trained, professional palates are terrible at judging wine.

In July, Watch Out for Lightning

Our Freakonomics Radio podcast "Women Are Not Men" mentioned that roughly 80 percent of lightning fatalities in the U.S. are men. A new National Weather Service report, summarized by io9, offers further details:

  • Soccer players and fishermen are more likely to get hit by lightning than golfers.
  • Saturday is the worst day of the week for lightning fatalities.
  • July is by far the deadliest month for lightning deaths.

(HT: Eric M. Jones)

FREAK-est Links

1. In Nashville, Tenn., homicide is at a historic low. (HT: Wesley Hartline)

2. We investigated suicide in our podcast "The Suicide Paradox"; The New York Times profiles  Matthew K. Nock, Harvard's "suicide detective."

3. Does price affect adoption? NPR reports that black babies are cheaper to adopt. (HT: Eric Samuelson)

4. Why do theater tickets cost so much? A comparison of "Death of a Salesman" ticket prices in 1949 and 2012.

5. In India, proof of toilet is necessary for a marriage license. (HT: Tony Pappas)

Fighting Poachers From the Lab

Wildlife activists have a new method for fighting Africa's increasingly bold elephant poachers.  Historically, scientists and governments have struggled to determine whether a piece of ivory was poached illegally or was obtained before the 1989 international ban on ivory trading, which has left some African governments with enormous stockpiles of ivory to manage and protect.  But a team of scientists recently determined that it's possible to use the amount of radiocarbon in an ivory tusk to determine what year the animal died -- and, by extension, whether the ivory was illegally poached.  

"The amount of radiocarbon in the atmosphere nearly doubled during nuclear weapons tests from 1952 to 1962, which steadily dropped after tests were restricted to underground. This has been dubbed 'the bomb-curve,'" explains a BBC article on the study.  The resulting significant variations in atmospheric radiocarbon allow for highly accurate dating.  Scientists also hope that the technique will help shed light on poaching hotspots.  Kevin Uno, the study's lead author, told the BBC that the technique "would dovetail very nicely with DNA testing which tells you the region of origin, but not the date."

Can Connectivity Kill?

The standard narrative around technology in the developing world usually focuses on the positive: cell phones make it easier to check crop prices, transfer money, and understand violence.  But a new study, summarized in Foreign Policy, finds that all this connectivity can also increase political violence in violence-prone regions and countries:

new study by Jan Pierskalla of the German Institute of Global and Area Studies and Florian Hollenbach of Duke University looks at the relationship between mobile phones and political violence in Africa. They found that from 2007 to 2009, areas with 2G network coverage were 50 percent more likely to have experienced incidents of armed conflict than those without. The clearest overlaps between cell coverage and violence were observed in Algeria, the Democratic Republic of the Congo, Kenya, Nigeria, Uganda, and Zimbabwe.

The authors think that improved cell-phone coverage helps insurgent leaders overcome what's called the "collective-action problem" -- that people are reluctant to join group endeavors when there's a high level of personal risk. But better communication helps leaders recruit reluctant followers, whether they're demonstrating for higher wages or killing people in the next town.

Cookbooks and Economics

Writing for Foreign Policy, Tyler Cowen explains what cookbooks can tell us about economic development. Why is it easy to find Mexican food cookbooks, but impossible to find a cookbook detailing the recipe for Yemen's mutafayyah dish? Here's Cowen's economic explanation:

Consider how cooking evolves: It starts in the home and then eventually spreads to restaurants and on to cookbooks, along the way transforming a recipe from oral tradition to commercialized product. In the home, recipes are often transmitted from grandmother to mother, or from father to son, or simply by watching and participating. I've seen this in rural Mexico, for instance, when an older daughter teaches her younger sister how to pat tortillas the right way. When societies get richer, you start to see restaurants, a form of specialization like auto mechanics or tailors (see: Adam Smith on the division of labor). Restaurants require that strangers -- other cooks -- be taught the process. That means simplifying or standardizing ingredients so they're easier to work with and, in many cases, available year-round. This, of course, means writing down the recipe. Once a dish reaches these commercial milestones, cookbooks will follow.

Another Explanation for Sex Selection in China?

In a podcast called "Misadventures in Baby-Making," we explored China's one-child policy as a cause of sex-selective abortion and, therefore, skewed male-female sex rations. A new working paper (abstract; PDF) by Douglas Almond, Hongbin Li, and Shuang Zhang points to another possible culprit: China's economic liberalization. From the abstract:

Following the death of Mao in 1976, abandonment of collective farming lifted millions from poverty and heralded sweeping pro-market policies. How did China’s excess in male births respond to rural land reform? In newly-available data from over 1,000 counties, a second child following a daughter was 5.5 percent more likely to be a boy after land reform, doubling the prevailing rate of sex selection. Mothers with higher levels of education were substantially more likely to select sons than were less educated mothers. The One Child Policy was implemented over the same time period and is frequently blamed for increased sex ratios during the early 1980s. Our results point to China’s watershed economic liberalization as a more likely culprit.