A Herd-Mentality Nudge on the Singapore Subway

Our "Riding the Herd Mentality" podcast argued that one surprisingly effective way to encourage pro-social behavior is to simply tell people that everybody else is already doing it.

A reader named Freek Rijna -- "Jep, that's my real name and it's typically Dutch. :-)" -- sends in this example from the Singapore subway. "Thought you might enjoy it," Freek writes. "Not sure about the penguins though ..."

I see Freek's point. Also, I might have to stop for a minute to think whether "alighting" means getting off or getting on ...

Boycotts and Jerks

A reader named Ert Dredge writes in with the following set of trenchant observations and questions:

Hiya, Dubner 'n Levitt.

I was just listening to podcast #84 "Legacy of a Jerk," and it brought to mind a long-standing cocktail party question of mine:  Is it reasonable to boycott what someone does for a living, if you think they're good at it, because they're privately a jerk?

Is it reasonable to never watch Braveheart again because of Mel Gibson's anti-Semitism or other issues?
...or never watch another Roman Polanski film?
...or to have not listened to Cat Stevens during the whole Salman Rushdie fatwa issue (misunderstanding?)

And, if so, does that mean that boycotting my local shoe repair guy's business because he doesn't clean up after his dog is reasonable.

The Ongoing Battle Between Technology and Human Behavior

"It is conventional wisdom that it is possible to reduce exposure to indoor air pollution, improve health outcomes, and decrease greenhouse gas emissions in the rural areas of developing countries through the adoption of improved cooking stoves," write Rema Hanna, Esther Duflo, and Michael Greenstone in their new working paper "Up in Smoke:  The Influence of Household Behavior on the Long-Run Impact of Improved Cooking Stoves" (abstract; Washington Post coverage).

But, as the scholars discovered, what seems like an obvious technology fix doesn't always work. Because, remember, human behavior can be a lot harder to change than we think.

Or, put another way: bummer.

To Ask or Not to Ask: Experiments in Charitable Giving

Our recent podcast "What Makes a Donor Donate?" features economist John List, who has concentrated his research on the science of philanthropy. In short, when it comes to convincing people to give, some ways are better than others. But what about just directly asking them?

A new study from authors James Andreoni, Justin M. Rao, and Hannah Trachtman examines the way people behave when solicited for donations by bell-ringers from the Salvation Army Red Kettle Campaign. The authors designed an experiment where bell-ringers were sent to a grocery store in suburban Boston, and positioned at either one or both of the store's entrances.

Is Climate Change Affecting When People Visit National Parks?

Last year, 281.3 million people visited America's national parks, down 4.2 million from a year earlier. With parks such as Glacier likely to be glacier-less sometime around 2030, or sooner, authors Lauren B. Buckley and Madison S. Foushee (PDF here) track differences in attendance habits since 1979 to ask if climate change is affecting relatively mundane human activities such as park visitation:

Climate change has driven many organisms to shift their seasonal timing. Are humans also shifting their weather-related behaviors such as outdoor recreation? Here we show that peak attendance in U.S. national parks experiencing climate change has shifted 4 days earlier since 1979. Of the nine parks experiencing significant increases in mean spring temperatures, seven also exhibit shifts in the timing of peak attendance. Of the 18 parks without significant temperature changes, only 3 exhibit attendance shifts. Our analysis suggests that humans are among the organisms shifting behavior in response to climate change.

What Do Hockey Visors and Birth Control Hormone Shots Have in Common?

The New York Times recently reported that using Depo-Provera, one of the most popular contraceptives in eastern and southern Africa, may increase a person’s risk of transmitting HIV. I fear this is a case for The Guardian's Ben Goldacre… where a study gets a bit (understatement) too much spin in the media. I first became aware of this while in Uganda and saw the following headline in the local paper: “The injectable contraceptive that could double the risk of women contracting HIV.” That sure sounds like the shot itself does something. Or could this instead be a by-product of behavior change? Huge difference if you are deciding what birth control to use!

The Times article cited a study recently published in The Lancet, which showed that women using hormonal contraception—primarily the injection more commonly known in the U.S. by its brand name, Depo-Provera—were twice as likely to acquire HIV from their infected partners, and twice as likely to transmit the virus to their HIV-negative partners.

How an Absent Father Affects Boys and Girls Differently

According to the U.S. Census Bureau, the share of children living in mother-only households has risen from 8 percent in 1960 to 23 percent in 2010. Freakonomics has a long-standing interest in the role parents play in the lives of their children, and while we usually find no merit in helicopter parenting, a basic level of involvement is obviously important. Past research has shown that a father's involvement with his children is linked to all kinds of beneficial outcomes, from higher academic achievement, improved social and emotional well-being, to lower incidences of delinquency, risk taking, and other problem behaviors.

A new working paper from authors Deborah A. Cobb-Clark and Erdal Tekin examines the relationship between juvenile delinquency and the role of a father in the household, particularly in terms of the different effects an absent father has on boys and girls. They discovered, among other things, that sons benefit far more from a father (or father-figure) than daughters do. From the abstract:

...we find that adolescent boys engage in more delinquent behavior if there is no father figure in their lives. However, adolescent girls' behavior is largely independent of the presence (or absence) of their fathers.

Author Steven Pinker Answers Your Questions

Last week we solicited your questions for author and Harvard psychology professor Steven Pinker on his new book, The Better Angels of Our Nature: Why Violence Has Declined. You responded quickly with more than 50 questions. Now, Pinker is back with his answers to 10 of them. The result is a fascinating discussion (exactly the kind we like to have around here) on the roots of violence, the rationale for wars of the past and what a decrease in violence says about modern society. As always, thanks to everyone for participating.

Q Any thoughts on the negative side effects of decreased violence? Overpopulation? More sedentary populations? Decreased role for survival of the fittest? Not to say that violence is preferable, just wondering about the downsides of peace. - BL1Y

Bring Your Questions for Willpower Authors Roy Baumeister and John Tierney

What's the most coveted human virtue -- empathy? honesty? courage?

Or how about ... self-control?

That's the assertion of the new book Willpower: Rediscovering the Greatest Human Strength*, by Roy Baumeister, a research psychologist at Florida State, and John Tierney**, a New York Times science writer. The book builds off Baumeister's research on the physical aspect of willpower, which he and his research collaborators found behaves like a muscle: it can be strengthened through exercise but it becomes fatigued from overuse. Willpower is generated in large part by sleep and diet, and feeds off of the glucose in our bloodstream.

Baumeister and Tierney argue that our ability (or inability) to exercise self-control is most often the key between success and failure. And it's hard not to see their point: I type these words on the very day that a special election is being held in New York to replace the disgraced (and aptonymic) Congressman Anthony Weiner.

Mandating Calorie Counts: Has Libertarian Paternalism Gone Too Far?

Staring at the menu board on a recent and rare trip to a California fast-food chain, I was stunned by the cost of a milk shake: 880. Eight dollars for a milk shake, really? Well, no. That was the cost in terms of calories. But I would have gladly traded that in dollars and cents to be spared the knowledge of how many calories my post-triathlon race reward would cost me. Feeling sufficiently guilty once confronted with the calorie content, I downsized and saved a couple hundred calories. But I left feeling dissatisfied and unambiguously worse off.

This kind of experience could be coming to a restaurant near you by January, when the FDA plans to roll out mandatory calorie labeling regulations approved by Congress in the same bill that authorized ObamaCare. At chain restaurants with more than 20 locations, you won’t be able to avoid the calorie information, which is prescribed to be posted on menus and menu boards near prices and printed at least as large. So much for the days of blissful ignorance.

While the calorie labeling law is intended to improve health outcomes for individuals, it is effectively a government-mandated guilt trip and a sign that libertarian paternalism—the seemingly benign notion that “choice architects” can “nudge” people to make better decisions for themselves—has gone too far.