Here is the abstract to The Geography of Poverty and Nutrition: Food Deserts and Food Choices Across the United States (free version) by Allcott, Diamond, and Dubé:

We study the causes of “nutritional inequality”: why the wealthy tend to eat more healthfully than the poor in the U.S. Using two event study designs exploiting entry of new supermarkets and households’ moves to healthier neighborhoods, we reject that neighborhood environments have economically meaningful effects on healthy eating. Using a structural demand model, we find that exposing low-income households to the same food availability and prices experienced by high-income households would reduce nutritional inequality by only 9%, while the remaining 91% is driven by differences in demand. In turn, these income-related demand differences are partially explained by education, nutrition knowledge, and regional preferences. These findings contrast with discussions of nutritional inequality that emphasize supply-side issues such as food deserts.

This is a good paper with a credible research design and impressive data from some 35,000 supermarkets covering 40% of the United States. Moreover, because of the widespread attention given to “food deserts” this paper probably had to be written. But color me un-surprised. The results are obvious.

Indeed, I feel that in recent years I am reading a lot of papers that aim massive firepower on weak hypotheses. As an explanation for obesity and poor eating habits, the idea of “food deserts” was absurd. The reasons are manifold. Even in food deserts it’s actually not that difficult to get healthy food and, contrary to popular belief, healthy food is not especially expensive. Try an Asian supermarket for plenty of cheap produce. Indeed, in any part of the United States you can find plenty of poor-people eating healthy foods and plenty of rich people eating unhealthy foods.

The food deserts idea was especially implausible for America because Americans spend less of their income on food consumed at home (6%) than any other nation. The Dutch, for example, spend (12%) of their income on food, the Italians and Japanese (14%), the Vietnamese (35%). There is plenty of room in the American food budget for healthy eating. Finally, Allcott, Diamond, and Dubé show that relative to unhealthy food, healthy food is actually a bit cheaper in low-income areas.

More importantly, just open your eyes. Walk into a fast food joint in a food desert and ask yourself, do the customers really want brussel sprouts but are reluctantly settling for Chips Ahoy? The idea is ridiculous and not a bit insulting in denying agency to the people who live in low-income areas. If what people living in food deserts wanted was brussel sprouts, they would get them.

The Whole Foods class think their kale and kombucha are so obviously superior to what the poor eat that the only possible explanation for poor eating is that poor people are denied choice. Yet put an inexpensive but colorful produce stand next to a McDonald’s and you can be sure that the customers will differ by class. Why the poor choose to eat differently than the rich is an interesting and important question but one more amenable to answers focusing on culture, education and history than price and income. The idea applies widely.