This article argues that central cities and their surrounding regions are highly interdependent, and that neither suburbs nor central cities are self-sufficient. For example, suburban per capita income is linked to central city per capital income, and the price of peripheral "edge city" office space is linked to the price of office space in the central business district. Not only do many suburbanites earn their incomes in central cities, but the authors also find that the amounts of income generated in core cities continue to grow. Overall, strong statistical evidence shows that suburbs benefit when their core cities are viable (densely populated and prosperous) and that when cities include a greater proportion of their metropolitan populations, they tend to be more prosperous.