Frequently Asked Questions
Where does PlainFoodAccess data come from?
PlainFoodAccess uses three federal data sources: the USDA Economic Research Service Food Access Research Atlas (primary food access indicators), the U.S. Census Bureau American Community Survey (demographics and income data), and the USDA Food and Nutrition Service (SNAP participation statistics). All are publicly available federal datasets.
What is a food desert?
A food desert is a Census tract that meets two criteria set by the USDA: it is low-income (poverty rate of 20% or more, or median family income at or below 80% of the area median), AND it is low-access (residents live more than 1 mile from a supermarket in urban areas, or more than 10 miles in rural areas). PlainFoodAccess uses this official USDA definition without modification.
How does PlainFoodAccess define 'low food access'?
The USDA uses distance thresholds to define low food access: more than 1 mile from a supermarket in urban areas, and more than 10 miles in rural areas. Vehicle access variants also track households without a car that live more than half a mile from a store. PlainFoodAccess presents all USDA-defined variants without adding custom thresholds.
Does PlainFoodAccess show tract-level data?
No. The USDA Food Access Research Atlas data is collected at the Census tract level, but PlainFoodAccess aggregates that data to the county level for its profiles. County-level data provides a reliable, comparable view across all 3,144 U.S. counties. Tract-level detail is available directly from the USDA ERS website.
What is SNAP and where does that data come from?
SNAP (Supplemental Nutrition Assistance Program) is the federal food assistance program commonly known as food stamps. SNAP participation data on PlainFoodAccess comes from the USDA Food and Nutrition Service (FNS), which publishes state and county-level participation counts through federal data portals.
How current is PlainFoodAccess data?
PlainFoodAccess uses the most recent available release of the USDA ERS Food Access Research Atlas, combined with the most recent five-year Census ACS estimates. The USDA updates the Atlas periodically, the current release reflects the latest published version. SNAP data reflects the most recent USDA FNS release. PlainFoodAccess refreshes its database when updated federal datasets are published.
Is PlainFoodAccess affiliated with the USDA or government?
No. PlainFoodAccess is an independent data portal built by PlainFoodAccess. We present publicly available federal data in an accessible, searchable format but are not affiliated with the U.S. Department of Agriculture, the Census Bureau, or any government agency. For official food access resources, visit the USDA ERS website directly.