U.S. AFFLUENCE IN 1990
The most affluent 5 percent of counties in 1990 are mapped
in Figure 7, and details of their distribution is provided
in Table 4. In 1980 the most affluent 5 percent of counties
were located in 28 states, and by 1990 this number had expanded
to 32. However, these counties were even more concentrated in
particular states with 23 in Virginia, 12 in New Jersey, 11 in
Maryland, and 9 in both Illinois and New York. The most affluent
50 counties are located in 19 states, with the greatest number
in Virginia (9), New Jersey (6), Maryland (5), New York (4), and
Connecticut (4). The most affluent county in 1990 was again Los
Alamos County, New Mexico. Los Alamos County represents an unusual
situation, and has an INDEX that is over 226 percent higher than
the next most affluent county in New Mexico. Los Alamos is very
small compared to other counties in New Mexico with an area of
approximately 109 square miles, and a population of just over
18,000 in 1990 (Figure 8). The county has a unique history, and
was created in 1949 out of portions of adjacent Sandoval and Santa
Fe counties that had been the location for the Manhattan Project
from 1942 to 1946. The area was administered by the federal
government during the project, and the legacy from the specialized
purpose for which the area was delineated is still apparent today.
For example, 65.5 percent of the population 25 or older hold a
bachelor's degree or higher, and median household income is $110,190
(U.S. Census Bureau 2018b).
The most affluent 5 percent of counties in 1990 was even more
concentrated in metropolitan areas in 1990 than they were in 1980.
The cluster of rural affluent counties in Wyoming is no longer
apparent, and of the 157 most affluent counties 151 are located
in 55 metropolitan areas. In 1980 the number of metropolitan areas
with affluent counties was 49 so the number of these counties expanded.
However, it is clear that affluent counties further concentrated in
just a few metropolitan areas that typically cross state boundaries
(Table 4). Washington DC, Chicago, Philadelphia, and New York have
17, 14, 8 and 8 respectively in the most affluent 5 percent of counties,
and 28 of the 50 most affluent counties are in those same metropolitan
areas (Table 4). It is relatively easy to visually identify major
metropolitan areas on Figure 7, and the 'BosWash' megalopolis stands
out as a region of affluence even more so than it did in 1980.
Figure 7. The Most Affluent 5 Percent of Counties, 1990
Figure 8. New Mexico Counties (Los Alamos)
Table 4. Metropolitan Areas with Counties in the Most Affluent [50] and 5 Percent: 1990
