COUNTIES IN NORTHEAST, MIDWEST CONTINUE TO OFFER BEST ACCESS TO U.S. POPULATION, STUDY SHOWS
COLUMBUS, Ohio – While locations in the Northeast and Midwest continue to be most accessible to the largest concentrations of people in the United States, research shows that areas in the South and West are making inroads.
A new study examines, for each county in the continental United States, how much of the nation’s population lives within a certain distance of the county’s center. The result is a population “accessibility” score for every county.
This research is important because cities and counties often tout accessibility to a large proportion of the nation’s population as an advantage as they try to land new business and industry, said Morton O’Kelly, co-author of the study and professor of geography at Ohio State University.
O’Kelly and a colleague examined how accessibility scores changed from 1990 to 2000 and found that the leading edge of top-tier accessibility has inched southward from the Midwest and Northeast to include significant portions of North Carolina and Tennessee.
“The increased prominence of southern locations in the top tier reflects the cumulative effect of migration of people from the Frost Belt to the Sun Belt,” O’Kelly said.
“We know that much of the population growth in the 1990s was concentrated in the South and Western United States and this has improved their accessibility to concentrations of population.”
In fact, results showed the five counties with the largest percentage growth in accessibility scores between 1990 and 2000 were all in one Western state -- Arizona (Maricopa, Pinal, Gila, Pima and Yavapai counties).
But while these Western counties have had large percentage gains in accessibility, they are still far behind the major Northeastern metro areas in terms of overall access to population and sheer number of people added over time.
The top five counties in terms of the most people added within 50 miles between 1990 and 2000 were all in New Jersey and New York (Morris, Somerset, Bergen and Union counties in New Jersey and Richmond County, New York).
O’Kelly conducted the study with Mark Horner, a former graduate student at Ohio State, now an assistant professor at Southwest Texas State University in San Marcos, TX. Their results are published in the current issue of the Journal of Geographical Systems. O’Kelly said the study was designed to give a national perspective on the issue of accessibility.
“We see chambers of commerce in many cities and counties brag that a given percentage of the nation’s population is within a day’s drive of their location, as if nowhere else were accessible,” he said. “We wanted to offset this local measurement with a more panoramic view of accessibility at a national scale.”
O’Kelly and Horner examined accessibility using several different measurements. They examined populations within 50 miles of a county, and also within 100 miles. They also did calculations in which they gave diminishing weight to population as the distance from the county increased. There were some differences in results, but overall trends were similar. For example, no matter how they did the analysis, the top five accessible counties in the United States were, not surprisingly, in the New York City metropolitan area.
In general, the Northeast counties were most accessible and accessibility scores declined as you move west until reaching California. Between 1990 and 2000, accessibility scores were flat or even declined in many of the counties of the Plains states, the Mississippi River basin and the Appalachian region as a result of flat or declining populations.
In addition to looking at changes in accessibility between 1990 and 2000, the researchers also went back to 1940 to see more long-term changes.
While the counties with the largest percentage growth in accessibility scores between 1990 and 2000 were all in Arizona, the results for 1940 to 2000 favored Florida counties. In this 60-year span, the greatest gains in accessibility were in three Florida counties (Broward, Miami-Dade, and Monroe counties) as well as two counties in Arizona (Maricopa and Pima).
In terms of the largest number of people added within 50 miles of a county, the top five between 1990 and 2000 were all in New York and New Jersey. But between 1940 and 2000, four of the top five were in California (Los Angeles, Ventura, Contra Costa and Fairfield counties) and only one in New York (Nassau County).
Overall, trends in accessibility are relatively stable, O’Kelly said. However, as this study showed, growth in areas of the South and West will make some of the counties there more appealing to businesses looking for access to large populations of potential customers.
“If you’re a franchise owner or a media conglomerate, you want to know what kind of population is around you that you can easily reach,” he said. “The Northeast and Midwest still leads, but there is strong growth in parts of the South and West.”