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Another Supply-and-Demand Obesity Explanation

It is hard to tune out all the talk about obesity in this country. In the past, such talk has led me to ponder how serious the problem really is, how obesity is measured, etc. It has even led to the suggestion that higher oil prices may help curtail U.S. obesity.

Now here is a new working paper called “Why Is the Developed World Obese?” by Sara Bleich, David Cutler, Christopher Murray, and Alyce Adams. They conclude that “rising obesity is primarily the result of consuming more calories” (as against declining physical activity), and that “the increase in caloric intake is associated with technological innovations such as reduced food prices as well as changing sociodemographic factors such as increased urbanization and increased female labor force participation.”

In other words: when there is a lot of tasty food around and it is relatively cheap, people tend to eat a lot of it.

Nothing in this theory contradicts Seth Roberts’s understanding of the human appetite mechanism; nor does it contradict the fact that we live in a country where even poor people can afford to be obese. The link between poverty and obesity is so robust that it is easy to forget what an anomaly this is in historical terms.

[Addendum: a forthcoming paper by Jonah Gelbach, Jonathan Klick, and Thomas Stratmann, called “Cheap Donuts and Expensive Broccoli,” also explores the relationships between obesity and price, arguing that “as healthful foods become more expensive relative to unhealthful foods, individuals substitute to a less healthful diet.”]