American Health Fail: What’s Making Us Fat? A Decline in Smoking
Americans are fat. The latest obesity estimates reach as high as 30% of the population. The future looks worse. There’s been much hand wringing over the years, with a new television show sprouting up every season imploring the obese to lose weight. But everyone wants to know: why is this happening?
Researchers Charles Baum and Shin-Yi Chou provide a detailed look at the leading indicators of weight, using the National Longitudinal Survey of Youth from 1979 and 1997 to compare the habits, similarities and differences between people of the same age – just a quarter century apart. The results aren’t pleasant: the largest effect on our recent weight gain? The decline in cigarette smoking. Read More »
What Percentage of Microfinance Loans Actually Go to Business Investment?
If someone with a clipboard came up to you in the street and asked you if you secretly harbor racist views, have stolen things in the past, had unprotected sex, or some other illicit behavior, how likely would you be to tell the truth?
Probably not very. This causes havoc for any researcher who wants to study behavior that may deviate from social norms in some way. A survey technique called “list randomization” allows researchers to calculate the average response to a question in a population, without being able to identify the response of any one individual. In theory this gives people the freedom to answer truthfully, knowing that even the interviewer won’t be able to tell what they answered.
This method has indeed been used to measure hidden racism and sexism among American voters, as well as all sorts of bad behavior by American teens.
In a paper, forthcoming in the Journal of Development Economics, Jonathan Zinman and I apply this approach to the question of how the poor spend their microfinance loans. Read More »
Movie Review Bias: Time Warner vs. News Corp.
Does media concentration lead to biased coverage? A new paper from two Berkeley economists, Stefano Delavigna and Alec Kennedy, studies News Corp. and Time Warner, and approaches the big question through a small window: movie reviews. Here’s the abstract: Read More »
The Vanishing Walk to School
Since the late 1960s, the share of U.S. kids and teens who are overweight has more than tripled. Why? I personally find Ronald McDonald kind of sinister, but it’s possible that Happy Meals might not deserve all the blame. In fact, Noreen McDonald—no relation to Ronald—of the University of North Carolina at Chapel Hill has analyzed a trend that might be contributing to the alarming rise in childhood obesity. Kids today aren’t walking or biking to school like they used to.
In 1969, the National Household Travel Survey found that roughly 41% of school-age children/teens got to school by “active travel” (i.e. walking and biking, though mostly walking, which then and now is more than 10 times more prevalent than biking).
In 2001 the walk/bike share was down to roughly 13%, a pretty spectacular drop. For elementary school children the change was even more stark. Today, even students who live within one mile of school have a less than 50% chance of walking; about 86% of similarly situated students walked in 1969. Read More »
and 
. If you haven’t seen it yet, the movie features Steven Levitt and Stephen Dubner, and was made by a dream team of documentary directors. Paste Magazine named it one of the 