How does a consolidating supermarket industry affect food access for communities across the United States? What social and economic conditions may be driving the decision to close one grocery store, and open another?

The Grocery Gap Atlas, a new project from the UChicago Data Science Institute Open Spatial Lab and Rural Advancement Foundation International (RAFI), helps to explore these questions and more through an interactive data visualization platform that makes clean data accessible to the public. Launched in August with support from the Robert Wood Johnson Foundation, the Grocery Gap Atlas aims to better understand factors that contribute to food insecurity, starting with the grocery store. 

The Grocery Gap Atlas brings together multiple data sources through a free, open source online platform in order to:

• Visualize current and historical data to understand the impacts of consolidating grocery markets on food access; 
• Report and compare these measures in neighborhoods, counties, states, and nationally to uncover trends and intersections in inequities;
• Make clean data accessible for the public to use for further exploration; and
• Advocate for solutions that build a better food system through equity and accountability. 

Using the Grocery Gap Atlas, researchers and advocates can visualize trends in the data, identify places where trends intersect, and compare measures at different places, ranging from states and counties, down to individual Census tracts. The platform has several different features and functionalities through which users can explore the data. The main map visualizes multiple datasets on social, economic and demographic trends across the country, including food access, measured as access to grocery stores; corporate market concentration; and residential segregation. Reports give users a snapshot of the data on a specific place,— whether a state, county, or census tract —and see how measures of food access, corporate concentration, and demographic and  socioeconomic conditions have changed over time, as well as how they compare to other places. 

RAFI, a national nonprofit organization dedicated to challenging the root causes of unjust food systems, is using this new open source data tool to support public awareness and narrative change around the impact of corporate concentration in the food system. Grocery Gap Atlas will also be used as supportive evidence in their advocacy and educational efforts. The Open Spatial Lab partnered with RAFI to develop a mapping tool that would aggregate and visualize multiple datasets to explore these questions and support further analysis using open, low-code, and low-cost approaches. 

Access to this data for further analysis and exploration is important, particularly now. The Grocery Gap Atlas highlights its initial, high-level findings as case studies. Recent case studies explore correlations of corporate concentration and food access in rural Nebraska, break down state-level corporate concentration rates by parent company, and analyze the impact of a proposed corporate merger.

In October of 2022, the second largest grocery chain in the United States, Kroger, announced a planned $24.6 billion deal to acquire the nation’s fourth largest grocer, Albertsons. Under this deal, Kroger would become the second largest grocery chain in the United States with a market share nearly as large as Walmart’s. Regional grocery store chains controlled by Kroger in this scenario would include Albertsons, Harris Teeter, Ralphs, QFC, King Soopers, Vons, Safeway, Jewel Osco, and Acme. In 2024, the FTC filed suit to block the merger, contending that it would lead to higher prices and fewer choices for consumers, while eliminating critical competition for workers, negatively impacting wages, benefits, and working conditions. Project partner RAFI wanted to explore what the merger could mean for communities already facing long distances and limited selections of fresh foods at their nearest grocery stores. 

Using data from the Grocery Gap Atlas, we analyzed the potential impact of Kroger’s acquisition of Albertsons on the northwestern United States — specifically Washington, Oregon, Idaho, Montana, Colorado, and Wyoming — where Kroger and Albertsons as separate chains overlap and compete. Within the six states we analyzed, if a merger should occur, then the regional measure of corporate concentration would increase significantly; Kroger, by itself, would dominate more than half of the overall state grocery markets. The Grocery Gap Atlas data can be used to support more detailed analysis, precise modeling, and research on the impact of different scenarios. 

From a data science perspective, Grocery Gap Atlas uses a low-cost, open source, and maintainable technology stack. The Open Spatial Lab team built on their previous work with low-cost, low-code data tools, and utilized cloud-native data formats to deliver fast in-browser data analytics. The tool’s static file-based content management system (CMS) served through GitHub allows for RAFI to easily update content on the site — no coding required.  

For more information on the Grocery Gap Atlas and its data and methodology, visit https://grocerygapatlas.rafiusa.org. 

Grocery Gap Atlas is a project of the Open Spatial Lab and RAFI. RAFI is a national nonprofit that challenges the root causes of unjust food systems, supporting and advocating for economically, racially, and ecologically just farm communities. The Open Spatial Lab at the University of Chicago Data Science Institute creates open source data tools and analytics to solve problems using geospatial data science. Support was provided by the Robert Wood Johnson Foundation. The views expressed here do not necessarily reflect the views of the Foundation.