Working Paper: NBER ID: w15436
Authors: Zhenxiang Zhao; Robert Kaestner
Abstract: In this paper, we examine the effect of changes in population density--urban sprawl--between 1970 and 2000 on BMI and obesity of residents in metropolitan areas in the US. We address the possible endogeneity of population density by using a two-step instrumental variables approach. We exploit the plausibly exogenous variation in population density caused by the expansion of the U.S. Interstate Highway System, which largely followed the original 1947 plan for the Interstate Highway System. We find a negative association between population density and obesity and estimates are robust across a wide range of specifications. Estimates indicate that if the average metropolitan area had not experienced the decline in the proportion of population living in dense areas over the last 30 years, the rate of obesity would have been reduced by approximately 13%.
Keywords: urban sprawl; obesity; population density; instrumental variables; public health
JEL Codes: I12; J11
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| population density (J11) | obesity (I12) |
| highway plan (R48) | population density (J11) |
| highway plan (R48) | obesity (I12) |
| population density (central city residents) (R23) | obesity (I12) |
| population density (suburban residents) (R23) | obesity (I12) |