Dec 31, 2004
Published in: American Economic Review, v. 95, no. 2, May 2005, p. 253-257.
Posted on RAND.org on December 31, 2004
There has been concern about the dramatic growth in obesity seen in developed countries. This paper advances the view that a neoclassical interpretation of weight growth that relies on changing incentives does surprisingly well in explaining the observed trends, without resorting to psychological, genetic, or addictive models. Welfare-improving technological change has lowered the cost of calories and raised the cost of physical activity by making agricultural production more efficient and work more sedentary. The authors develop the implications of the idea that economic progress (as income growth, food price declines, and sedentary work) leads to weight gain when people behave efficiently. To make concrete the point that obesity is a side effect of progress, they offer an empirical example of how lower food prices (a result of technological change) improve nutrition. Results suggest the difficulty of improving welfare by "rolling back" obesity to earlier levels, because obesity is a side effect of welfare-enhancing progress.