Researchers examine patterns of minority suburbanization circling the nation's major cities

The research by Jeffrey Timberlake, a University of Cincinnati associate professor of sociology, and Aaron J. Howell, a UC sociology doctoral candidate, was presented Aug. 15 at the 105th annual meeting of the American Sociological Association in Atlanta.

The sociologists used census data and multi-level modeling techniques to investigate patterns of white and minority suburbanization from 1970 to 2000.

Over that period, developments in technology and the highway system brought opportunities for industries to build outside the core of major cities, drawing the population to the suburbs as well. Timberlake adds that the diversity of the nation's population was also growing, with a small increase in the African-American population and large increases in the Latino and Asian population via immigration.

Research has shown that over time, the white population was leaving the central city and spreading farther and farther out into the suburbs. The UC researchers wanted to examine, as scholarly articles have suggested, whether racial and ethnic minorities moving out of the central city were primarily moving into older, declining, formerly industrial suburbs that are often viewed as extensions of the inner city.

Coding the rings of suburbs surrounding the central cities, the researchers measured the difference between the average percentage of minorities in the central city and the first ring of suburbs, what they called the first-ring gap. Secondly, they measured what they called the ecological distance gradient -- the extent to which each successive ring had a lower or higher representation of a particular racial group -- and how it affected minority representation farther out in the suburban rings.

"We're showing that over time, whites have shifted from being more dominant in the central city and the inner ring suburbs to being more dominant in the outer ring suburbs," explains Timberlake. "Nevertheless, our data has not found that there is a dramatically higher concentration of minorities in the inner ring suburbs than the outer ring suburbs. It's relatively flat as we examine farther and farther out from the inner city.

"The reason for this, we believe, is that the way a minority population diffuses throughout a city or metropolitan area is not by filling in the first-ring suburbs and then moving to the second-ring suburbs and so on. Instead, the movement is more in a radial pattern as the minorities tend to move out from the central city," Timberlake says.

The researchers conclude that more study is needed to examine why certain sections of outer-ring circles appear more available to minorities than others, but they believe part of that is due to minority domination of central city tracts on the first-ring border, as well as the pre-existing socioeconomic status of suburbs where minorities have increasingly settled.

The research was supported by funding from the UC Charles Phelps Taft Research Center.