Welfare-Enhancing Technological Change and the Growth of Obesity

摘要

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. Although the recent rise in obesity has attracted attention, weight growth is not a recent phenomenon (Dora Costa and Richard Steckel, 1995). Weight has been rising consistently over the past 150 years, particularly during the immediate post-World War II period. As Figure 1 illustrates, the secular growth in weight has been accompanied by modest growth, or even declines, in calorie intake (Judith Jones Putnam and Jane E. Allshouse, 1999). This suggests the importance of both rising food intake and declining physical activity. The calorie and weight trends have coincided with a decline in the relative price of food, of around 0.2 percentage points annually, from 1950 to 2000 (Lakdawalla and Philipson, 2002).