Research Summary Obesity has increased in recent decades despite no increase in calorie consumption and a rise in dieting and exercise. While typically treated as a public health issue, obesity is also an economic phenomenon that is avoidable through behavioral changes. Economists expect these behavioral changes will be undertaken if their benefits outweigh their costs. In their Harris School paper, The Long-Run Growth of Obesity as a Function of Technological Change, University of Chicago researchers Tomas J. Philipson and Richard A. Posner examine whether the economic benefits and costs of obesity can be used to explain its variations across time and populations.