Do poorer people eat unhealthily because they don’t have access to grocery stores and fresh fruits and vegetables (and are more easily able grab fast food or convenience store options), or is it because their preferences for healthy food differs from higher income households? In a sense, this is a question of nature vs. nurture applied to healthiness of food consumption, and it is a lively debate related to questions about food deserts, convenience store regulations, zoning, and more.
This interesting and rigorous paper (gated version here) on the topic by Hunt Allcott, Rebecca Diamond, Jean-Pierre Dube, Jessie Handbury, Ilya Rahkovsky, and Molly Schnell was recently published on the topic in the Quarterly Journal of Economics. I blogged about this paper a couple years ago, but I mentioned again now that it’s been revised and put through the rigors of the peer-reviewed process, and because the implications are quite important. Here’s the abstract:
“We study the causes of “nutritional inequality”: why the wealthy eat more healthfully than the poor in the United States. Exploiting supermarket entry and household moves to healthier neighborhoods, we reject that neighborhood environments contribute meaningfully to nutritional inequality. We then estimate a structural model of grocery demand, using a new instrument exploiting the combination of grocery retail chains’ differing presence across geographic markets with their differing comparative advantages across product groups. Counterfactual simulations show that exposing low-income households to the same products and prices available to high income households reduces nutritional inequality by only about ten percent, while the remaining 90 percent is driven by differences in demand. These findings counter the argument that policies to increase the supply of healthy groceries could play an important role in reducing nutritional inequality.”
These findings suggest efforts to eliminate food desserts or to constrain offerings of convenience stores are likely to have minimal effects. This paper shows, like some of my work, that higher- income households tend to eat healthier than lower-income households. Want lower income people to eat healthier? Then, we probably need to think about ways to increase their incomes. Another possible solution, albeit difficult to successfully and cost-effectively implement, is nutrition and health education.