 In addition, suburbanization had enticed many of the more affluent residents to outlying railroad commuting towns and newer housing.The resulting reduction in Philadelphia's tax base and the resources of local government caused the city to struggle through a long period of adjustment, with it approaching bankruptcy by the late 1980s.Revitalization and gentrification of neighborhoods began in the late 1970s and continues into the 21st century, with much of the development occurring in the Center City and University City neighborhoods.