Access to Affordable and Nutritious Food: Updated Estimates of Distance to Supermarkets Using 2010 Data
by Michele Ver Ploeg
, Vince Breneman
, Paula Dutko, Ryan Williams
, Samantha Snyder, Chris Dicken
, and Phillip Kaufman
Economic Research Report No. (ERR-143) 54 pp, November 2012
What Is the Issue?
Efforts to encourage Americans to improve their diets and to eat
more nutritious foods presume that a wide variety of these foods
are accessible to everyone. But, for some Americans and in some
communities, access to healthy foods may be limited. In the 2009
report to Congress, Access to Affordable and Nutritious Food:
Measuring and Understanding Food Deserts and Their Consequences,
the U.S. Department of Agriculture estimated several indicators of
access to healthy food sources, based on population data from the
2000 Census and supermarket location data from 2006. This report
uses data from 2010 to provide updated population estimates of
spatial access to affordable and nutritious food. These estimates
refl ect openings and closings of supermarkets, changes in the
distribution of the population in relation to supermarkets, and the
effects of the 2007-09 recession, which include the expansion of
the number of low-income people and areas. Estimates by income,
vehicle availability, and other characteristics of the population
are provided in addition to estimates for those who live in
low-income neighborhoods. These estimates are based on data from
2010 and, therefore, precede Federal policy initiatives to reduce
barriers to food access, which began in 2011.
What Did the Study Find?
Updated estimates from 2010 data present a mixed picture of the
extent of food access challenges in the United States. First, there
was very little change in the distance to the nearest supermarket
between 2006 and 2010 overall, both in terms of the median distance
to the nearest supermarket and throughout the distribution.
Second, vehicle availability for households more than 1 mile
from a supermarket has improved. In 2010, 1.8 percent of all U.S.
households (2.1 million households) did not have a vehicle and were
more than 1 mile from a supermarket. This is a decrease relative to
2006, when an estimated 2.3 percent (2.4 million households) were
more than 1 mile from a supermarket and without a vehicle. The
number and percentage of households without a vehicle between
one-half to 1 mile from a supermarket also decreased in 2010.
In contrast, the number of people in low-income areas who are
more than 1 mile from a supermarket increased. In 2010, 29.7
million people, or 9.7 percent of the population, lived in
low-income areas (½ kilometer-square grids where more than 40
percent of the population has income at or below 200 percent of
Federal poverty thresholds for family size) more than 1 mile from a
supermarket, up from 23.5 million, or 8.4 percent, in 2006.
However, given the stability in the distribution of the population
relative to the nearest supermarket and in the number of
supermarkets overall, growth in the share of population in
low-income areas more than 1 mile from a store is likely due more
to the greater number of low-income areas in 2010 than in 2006, not
to substantial changes in store openings and closings.
Distance to the nearest supermarket by individual income level
and area income level differs from rural areas to urban areas. In
urban areas, low-income people (those with income at or below 200
percent of Federal poverty thresholds for family size) and people
in low-income areas are closer to supermarkets than moderate- and
highincome people and areas. But in rural areas, low-income people
and people in low-income areas are farther from supermarkets than
moderate- and high-income areas.
Examining the distance to only one supermarket does not provide
information on whether that supermarket is competitive as it may be
the one and only store in the area. Distance to the three nearest
supermarkets was estimated for the U.S. population and for
subpopulations as an additional indicator of the level of consumer
choice and competition among supermarkets. Estimates show that half
of the U.S. population lived within 2 miles of three supermarkets
in 2010, while 80 percent lived within 5 miles.
How Was the Study Conducted?
This study estimates several distance-based measures of
supermarket access. These measures proxy access to healthy and
affordable food for the overall U.S. population and for
subpopulations, including households without vehicles, populations
with low incomes, and populations that live in low-income areas.
Data on the total population-along with data on age, race, and
ethnicity-come from the 2010 Decennial Census. Data on income and
vehicle availability come from the 2006-2010 American Community
Survey. These population data were downcast, or allocated aerially,
to ½-kilometer-square grids that cover the entire U.S. land area.
Two 2010 lists of supermarkets, supercenters, and large grocery
stores (food stores selling all major categories of food and having
annual sales of at least $2 million) were combined to produce a
comprehensive list of stores that represent sources of affordable
and nutritious food. Distances from the center of each
½-kilometer-square grid containing population data to the center of
the grid containing the nearest store were estimated for the entire
population and for population subgroups. In addition to updating
the previous analysis, a new analysis of supermarket access in
Alaska Native, American Indian, and Native Hawaiian tribal areas is
presented, as well as estimates of the distance to the three
nearest stores as an indicator of the amount of competition and
consumer choice available.