Mega-Regions
Richard Florida says the future of the economy is in "mega-regions" -- linked up networks of cities. Paul Krugman is a skeptic, but Florida responds to some of his criticisms here. When titans clash, I think of a more trivial point to raise (non-trivial point -- environmental sustainability should be considered here), namely that I don't understand why Florida calls these things mega-regions.
The so-called "mega-region" in which I live -- Florida calls it BosNyWash, I think, while Krugman uses the more felicitous term Acelaland -- is geographically smaller than a traditional "region" like New England or the Pacific Northwest. The true mega-regions of the United States are longstanding geographic and cultural concepts like "the South" that are composed of distinct sub-regions and are much, much larger than Florida's multi-focal urban clusters.