DESPITE ONGOING EFFORTS to revitalize downtowns and neighborhoods, many of America's cities are fighting losing battles against decline. Problems associated with decreasing economic prosperity—including poverty, crime, unemployment, and housing shortages—have become too severe for most cities to conquer alone. Without aid from the outside few central cities will be able to break apart the vast concentrations of poverty within their borders and return to prosperity.

Increasingly people are realizing that despite their economic and racial differences, central cities and suburbs are not independent from each other, but part of a single region or metropolitan area. Though central cities suffer from many problems, they remain important within their regions, if for sometimes negative reasons. In many areas of the country decline has begun to spread from the central city into the suburbs. Experts have linked the economic health of the central...