  Recent research on the geographic locations of bank branches in the United
States has identified thresholds below which a given area can be considered to
be a "banking desert." Thus far, most analyses of the country as a whole have
tended to focus on minimum distances from geographic areas to the nearest bank,
while a recent density-based analysis focused only on the city of Chicago. As
such, there is not yet a nationwide study of bank densities for the entire
United States. This study calculates banks per square mile for U.S. Census
tracts over ten different ranges of population density. One main finding is
that bank density is sensitive to the measurement radius used (for example,
density in urban areas can be calculated as the number of banks within two
miles, while some rural areas require a 20-mile radius). This study then
compiles a set of lower 5- and 10-percent thresholds that might be used to
identify "banking deserts" in various urban, suburban, and rural areas; these
largely conform to the findings of previous analyses. Finally, adjusting for
population density using regression residuals, this paper examines whether an
index of economic deprivation is significantly higher in the five percent of
"desert" tracts than in the remaining 95 percent. The differences are largest
-- and highly significant -- in the densest tracts in large urban areas.
