Local food retail access

Many people feel that low-income neighborhoods have less access to supermarkets than other neighborhoods do.

In research published recently in the International Food and Agribusiness Management Review, my colleagues and I found otherwise:

In contrast with the conventional wisdom, the results show that high poverty block groups had closer proximity to the nearest supermarket than other block groups did, on average: 85.6% of high-poverty block groups had a supermarket within 1 mile, while 76.8% of lower-poverty block groups had a supermarket within this distance. 

This finding makes sense when you consider the average population density of poor neighborhoods. Low-income neighborhoods may be urban or rural, but on average they are more likely than other neighborhoods to be urban and population-dense. Supermarkets tend to locate reasonably close to where people live.

When measuring local food retail access, it is useful to recognize that most Americans drive to grocery stores. Even though low-income Americans are less likely to own an automobile, this basic reliance on driving is true even for most low-income Americans. We found that the population living far from a supermarket and lacking an automobile is fairly small:

Population density is a strong predictor of proximity to the nearest supermarket. Block groups with very high population density generally had very close proximity to a nearest supermarket. In block groups lacking a nearby supermarket, rates of automobile access generally were quite high (more than 95%), although this still leaves almost 5% of the population in these areas lacking both an automobile and a nearby supermarket.

Other recent research on the food retail environment similarly emphasizes the importance of automobile access. For example, see a fascinating report by Mabli and Ohls (.pdf) on the website of USDA's Food and Nutrition Service.

It is worthwhile to compare these findings to other influential literature on lack of access to supermarkets. The online tool from the Reinvestment Fund identifies areas with Limited Supermarket Access (LSAs). The detailed report (.pdf) from the Reinvestment Fund agrees with our findings in several respects. For example, Table 2 in the TRF report confirms that low-population-density neighborhoods tend to have high average rates of automobile access (above 95%). Table 3 in the TRF report shows that neighborhoods with higher population density and lower average rates of automobile access typically have very short median distances (much less than a mile) to the nearest supermarket. The Reinvestment Fund classifies a particular neighborhood as having Limited Supermarket Access if the nearest supermarket is farther than a threshold distance based on non-poor neighborhoods with similar automobile access and population density. In urban areas, the threshold distance may be four fifths of a mile away, and in some cases merely a third of a mile away.

Because supermarkets are an automobile-oriented retail format, I have some misgivings about defining limited access using such short threshold distances, even for low-income populations. But I am eager to hear the views of others on that question.

The implied remedy in any method for identifying areas without supermarkets is to invite or persuade a supermarket to locate in a particular location. The new supermarket outlet will have to compete with other stores that customers at all income levels may prefer. The new store will not have a captive market. Of course, if communities put great effort into attracting a supermarket, we hope it will succeed and thrive once it gets there!

What if Walmart paid employees enough to avoid food stamps?

I enjoyed this video for sharp writing, clarity of data presentation, and measured tone.

While still relying on economic markets for a thriving food economy, we nonetheless can expect our major grocery chains to do better on wages. No matter what one thinks of the proposed federal minimum wage increase, it is clear that the nation's leading employers should face binding social norms that constrain them to pay wages that reach a certain threshold.

What should the threshold be? It is possible that some threshold would be too high, counter-productively putting grocery companies out of business. But, this video focuses on a much more humble and minimal threshold. At the very least, major grocery chains should pay wages sufficiently high to keep workers off the Supplemental Nutrition Assistance Program (SNAP) rolls.

Revitalizing Detroit with food and agriculture

Some amazing good things are happening in Detroit's food system.

Betti Wiggins, Director of Nutrition Services for Detroit Public Schools, is carrying out her vision for converting underutilized land to vegetable gardens.  Hear it in her own voice, from the Detroit Stories project.




The Detroit Eastern Market, operating continuously since the 1890s, offers a major regional event each Saturday and serves as a focal point for food business initiatives throughout the city.

Credit: http://www.detroiteasternmarket.com/.

See also the Detroit Food Policy Council, whose annual report (.pdf) provides greater detail about food system initiatives; the Colors Restaurant, an experiment in good food and worker justice; the Kitchen Connect project from Detroiters Working for Environmental Justice; the food system work of Detroit's youth movement; and the role of food initiatives in the broader Detroit Future City community planning initiative.

Any visitor to Detroit is struck by the depth of economic distress, visible in the physical environment and people one meets throughout the city.  The city population has declined by 25% in recent years.  Detroit is on the brink of bankruptcy (npr) and an emergency manager has been appointed (nytimes).

The remarkable entrepreneurs and innovators who are driving forward with new investments in food businesses and public initiatives are some of the most faithful, dauntless personalities I have ever met.

Food value chains beyond the farm gate

USDA's Economic Research Service has long published a well-known graphic illustrating the food value chain as a dollar bill, with each segment showing a particular industry's contribution to the average consumer dollar spent on food.

A key insight from this graphic is that farmers on average receive only about 10 cents for every dollar of consumer food spending.

It may be more surprising to hear how rapidly value chains around the world are changing, even for staples such as rice and potatoes.  A December report from the International Food Policy Research Institute (IFPRI), by Thomas Reardon, Kevin Chen, Bart Minten, and Lourdes Adriano, describes this change as a Quiet Revolution. Although the supermarket-ization of the food system in developing countries introduces risks and challenges, the report seems to me fairly upbeat.  It emphasizes several ways that economic development of the value chain can offer benefits for poor farmers and consumers, leading to improved food security.  To supply the megacities of countries like China, India, and Bangladesh with sufficient food, we cannot think just about traditional farmers selling raw commodities to a local merchant trader.  Instead, it is necessary to come to grips with modernization even in the food system that serves the world's poor consumers.

The carbon footprint of food

Recently, I was in the market for a good layperson's summary of the environmental impact of food choices.  The one I liked best so far was the brief chapter on food late in the book How Bad Are Bananas?: The Carbon Footprint of Everything, by Mike Berners-Lee.

Berners-Lee takes measurement seriously.  At the same time, he is completely frank about how rough some measurements are.  He doesn't waste time figuring out every last significant digit.  Instead, he stays focused on the information that really matters for making sensible lifestyle choices.

Berners-Lee has a talent for explaining technical material.  As just one simple example, he has a delightfully clear explanation of a financial discount rate, an important concept for evaluating payback periods for investments (p. 188).  Other authors might be tempted to skip the topic, but Berners-Lee recognizes that the layreader can understand this issue, without needing any equations.

From the food chapter, here is a summary food tips:

• Eat what you buy. 
• Reduce meat and dairy.
• Go seasonal, avoiding hothouses and air freight.
• Avoid low-yield varieties.
• Avoid excessive packaging.
• Help the store reduce waste.
• Buy misshapen fruit and vegetables.
• Lower-carbon cooking. 

On related issues, I enjoyed seeing a presentation at the Friedman School's Wednesday seminar series last week by Susanne Freidberg from Dartmouth College, who spoke about Life Cycle Analysis (LCA).  Her most recent book is Fresh: A Perishable History.

Among other topics, Freidberg described the use of LCA in corporate sustainability initiatives, of which a leading example is Walmart's.  Although a major retailer won't say "reduce meat and dairy" or "avoid excessive packaging," I nonetheless find the Walmart initiative interesting.  Just for example, this video is blunt: "The raw truth is that the design of this system is unsustainable."  And it provides a nice visual explanation of a food product's life cycle.

Choices Magazine: An evaluation of food deserts in America

A Choices Magazine theme issue released today explores the economics of food deserts.

Guest editors Dave D. Weatherspoon, Shelly Ver Ploeg, and Paula Dutko provide the theme overview and links to four more articles.  Weatherspoon and colleagues use data from a natural experiment, when a new retailer set up shop in a low-income neighborhood of Detroit.  Tatiana Andreyeva suggests that WIC's new fruit and vegetable vouchers may have improved the healthfulness of local food retail in Connecticut.  Dutko reviews the economic disadvantages observed in food deserts.  And Alessandro Bonanno's article stands out for its attention to the economics of food retail supply as well as consumer needs.  Attention to both need and supply is essential for people who want to think sharply about the food retail improvements that are truly feasible, not merely wishful thinking.

Supermarket deserts by the numbers

Gina Kolata in the New York Times this week cast doubt on claims that supermarket deserts contribute to the obesity epidemic.  The start of her article cites recent research that finds no association between supermarket deserts and risk of obesity.  It notes that residents of low-income urban neighborhoods have as much access to supermarkets as residents of higher-income neighborhoods have. 

This fact at first seems counter-intuitive to most people concerned about supermarket deserts, but it is easy to understand with some further reflection.  Low-income urban neighborhoods commonly have high population density, and they contain many medium-income residents along with the impoverished residents, so they sometimes offer too big a market for retail chains to overlook. 

The NYT article generated some controversy.  Conservative pundits, as you might imagine, falsely claimed that food deserts are a "make-believe issue" and an "Obama lie."  The liberal website Media Matters debunked the conservative coverage with typical thoroughness.  Media Matters also found "food experts" to characterize the NYT article as "misleading," which I think was too harsh a description for reporting that seemed basically sound. 

My favorite authoritative statistics about the extent of supermarket deserts put the problem into quantitative perspective, without exaggeration.  The key thing to understand is that most Americans, rich and poor, shop in supermarkets and supercenters.  Likewise, most Americans, rich or poor, shop by automobile.  Supermarkets and supercenters are fundamentally an automobile oriented retail format, and if we pretend that most people walk to the grocery store we will misdiagnose the problem.

USDA's 2009 Report to Congress about supermarket deserts emphasizes statistics showing how many households are far from a supermarket and lack access to a vehicle:

• 2.3% of U.S. households live more than 1 mile from a supermarket
  and lack vehicle access.
• 5.7% of U.S. households live more than 0.5 miles from a supermarket
  and lack vehicle access. 

One gets much higher percentages by ignoring vehicle access, but that approach is misleading.  One cannot ignore vehicle access, because, even in low-income areas, most grocery trips are by automobile.  The USDA report finds (in Table 2.9):

• In low-income areas with high access to food retail, about 65.3% of
  grocery trips are by automobile.
• In low-income areas with poor access to food retail, about 93.3% of
  grocery trips are by automobile.

Naturally, neighborhoods with adequate retail have a higher concentration of people without cars.  And in rural areas without adequate retail, even most low-income Americans shop by car.

My best summary of the evidence is that perhaps 2 to 6% of U.S. households lack good supermarket access.  Food retail access is a serious concern for people without vehicle access.  Possible remedies to improve local food retail have some merit, but should be carefully targeted based on need, and one should not expect these remedies to carry much of the burden of solving the obesity epidemic for the population as a whole.

Some low-income neighborhoods are supermarket deserts and some are not.

South Side Chicago

While in Chicago this month for an AAEA-sponsored session of the main annual meeting of economists, I took a long walk through the South Side neighborhoods from 35th Street/Bronzeville to 51st Street, learning especially about food retail access, housing, and other topics. Here are some photographs.


For advance preparation, I read Mari Gallagher's reports on food deserts in Chicago.

My past walks on the same theme include Skid Row, Anacostia, Harlem, Roxbury, and the Hill District.

May 2012 workshop on the "food environment"

Colleagues in the Agricultural and Applied Economics Association (AAEA) and its European sister organization are organizing an upcoming workshop on food retail, food access, and the food environment.  I am assisting with the local organizing for the workshop, here at Tufts.

Here is the open request for abstracts.

Abstracts submissions are due November 1, 2011 for the Food Environment: The Effects of Context on Food Choice conference jointly organized by AAEA and EAAE. The conference will take place May 30-31, 2012 at Tufts University in Boston.

The conference is aimed at providing insights into the influence of the food environment on the quality, price, and availability of food, associated health or environmental impacts, and to uncover the impact of policies aimed at influencing the food production and choice. For more information, including abstract submission instructions, please visit the conference website.