THE GROWTH OF OBESITY AND TECHNOLOGICAL CHANGE: A THEORETICAL AND EMPIRICAL EXAMINATION
Darius Lakdawalla Tomas Philipson
Working Paper 8946 http://www.nber.org/papers/w8946
NATIONAL BUREAU OF ECONOMIC RESEARCH 1050 Massachusetts Avenue Cambridge, MA 02138 May 2002
We wish to thank seminar participants at AEI, The University of Chicago, Columbia University, Harvard University, MIT, The University of Toronto, UCLA, Yale University, the 2001 American Economic Association Meetings, the 2001 Population Association of America Meetings, the 12 th Annual Health Economics Conference, as well as Gary Becker, Shankha Chakraborty, Mark Duggan, Michael Grossman, John Mullahy, Casey Mulligan, and Richard Posner. Neeraj Sood and Erin Krupka provided excellent research assistance. The views expressed herein are those of the authors and not necessarily those of the National Bureau of Economic Research.
© 2002 by Darius Lakdawalla and Tomas Philipson. All rights reserved. Short sections of text, not to exceed two paragraphs, may be quoted without explicit permission provided that full credit, including © notice, is given to the source.
The Growth of Obesity and Technological Change: A Theoretical and Empirical Examination Darius Lakdawalla and Tomas Philipson NBER Working Paper No. 8946 May 2002 JEL No. I1
ABSTRACT This paper provides a theoretical and empirical examination of the long-run growth in weight over time. We argue that technological change has induced weight growth by making home- and marketproduction more sedentary and by lowering food prices through agricultural innovation. We analyze how such technological change leads to unexpected relationships among income, food prices, and weight. Using individual-level data from 1976 to 1994, we then find that such technology-based reductions in food prices and job-related exercise have had significant impacts on weight across time and populations. In particular, we find that about forty percent of the recent growth in weight seems to be due to agricultural innovation that has lowered food prices, while sixty percent may be due to demand factors such as declining physical activity from technological changes in home and market production.
Darius Lakdawalla RAND 1700 Main Street Santa Monica, CA 90407 and NBER firstname.lastname@example.org
Tomas Philipson Irving B. Harris Graduate School of Public Policy The University of Chicago 1155 E. 60th St. Chicago, IL 60637 and NBER email@example.com
Policymakers and the public have been concerned about the dramatic growth in obesity seen in many developed countries over the last several decades. Close to half the US population is estimated to be over-weight and more Americans are obese than smoke, use illegal drugs, or suffer from ailments unrelated to obesity. A substantial risk factor for most of the highprevalence, high-mortality diseases, including heart disease, cancer, and diabetes (Wolf and Colditz 1998, Tuomilehto et al. 2001), obesity affects major public transfer programs such as Medicare, Medicaid, and Social Security. Obesity also affects wages and the overall demand for and supply of health care, a sector that itself accounts for a sixth of the US economy. Obesity is typically treated as a problem of public health or personal attractiveness. While it is those things, it is even more an economic phenomenon. More than many other physical conditions, obesity can be avoided through behavioral changes, which economists expect to be undertaken if the benefits exceed the costs.1 Naturally, people may rationally prefer to be underor over-weight in a medical sense, because weight results from personal tradeoffs and choices along such dimensions as occupation, leisure-time activity or inactivity, residence, and, of course, food intake. Given the variation in their choices about weight, being either heavy or light may be as desirable from the individual’s standpoint as adhering...