Joel Kotkin's critique of “creative class” urban development exposed a problem with the idea that governments can revive cities by subsidizing districts aimed at skilled, educated, fashionable residents. The theory encouraged officials to spend heavily on amenities and redevelopment designed to attract the “hip and cool,” even though the economic benefits to everyone else were far from clear.

Modern communications and transportation have weakened the old connection between downtown residence and employment. Many creative-industry workers can choose where to live, while manufacturing and logistics—the kinds of industries that historically built cities around jobs—often receive less attention from planners.

Even Richard Florida, closely associated with creative-class theory, acknowledged that clustering talent produced little trickle-down benefit. Demographic evidence was also sobering: from 2000 to 2010, America's largest metropolitan cores gained relatively few residents compared with enormous suburban growth, and the supposedly hip cores of places such as Cleveland and St. Louis remained a tiny share of their metropolitan populations.

That makes it difficult to justify large subsidies as a strategy for reviving entire cities.