The type of development described here is sometimes called a "doughnut" pattern, characterized by an empty center surrounded by a ring of growth. The pattern is now found not only in older manufacturing centers like Chicago and Detroit, but also in rapidly growing metro areas like Columbus, Ohio and Indianapolis. There is no consensus of opinion on the effects of doughnut-style development or suburban sprawl. Some analysts bemoan the high cost of new infrastructure and inefficient allocation of resources, while others cite the free-market benefits of consumers choosing where they want to live. But the movement of population away from large urbanized counties to outlying suburban counties is not subject to debate.

This difference is one of the factors that has contributed to the movement of businesses out of Toronto to suburban communities — the so-called doughnut pattern of development in which city cores are hollowed out.

The numbers are new, but the story remains the same. Growth in income, population and jobs in the Chicago area continues to follow a doughnut pattern, with the central city coming up empty.