Does Human Capital Tend to Cluster in Center Cities or the Suburbs?

It's now conventional wisdom that human capital (what economists call educated people) is a key factor in the growth of cities and metro regions. Cities are engines of economic development, and the skilled people are the high-powered fuel that drives them.

Most studies of the role of human capital in regional economic growth track its effects on and across metro regions. But metros vary widely in size, shape, and spatial and demographic compositions; human capital doesn't always cluster in the same places at the same densities. The revitalization of the urban center in cities like New York, San Francisco, Boston, and others has fueled in-migrations of more skilled and affluent people. Other cities, like Los Angeles and Detroit, still suffer from the proverbial "hole in the donut" effect, with their more educated, higher income populations spread out across their suburbs while their urban centers lag.