Over at Where Blog, Brendan writes:
Without Pittsburgh, in the literal sense, Chicago would not crumble and blow away; to think so would be naive. But Pittsburgh is a part of a group of cities that, together, have allowed Chicago to experience its recent -- and rather stunning -- revival over the past two decades. As post-industrial Western mega-cities like Chicago, New York, or London began to try to pick themselves up after losing manufacturing jobs in the 1970s and 80s, they began to rely on what you could call innovation-intensive fields like biomedicine, design, information technology, and (of course) the arts. These are highly specialized fields, and ones that many traditional middle class workers were not trained or educated to participate in. Megacities, then, needed to draw in new talent from surrounding smaller cities.
The entire post is on point; Jim Russell responds here. Brendan is onto something. What globalization has done is to globalize and integrate the the city-system. Once upon a time, city-systems were national. They had core cities like New York, London, Paris or Tokyo and then a set of second, third, fourth and so tier cities all organized around industries and geographies. As production and innovation has spread around the globe, the city-system has been stretched out, and national systems have given way to an increasingly global one. Technically speaking, these national systems have always followed a rank-order or Zipf distribution; that distribution, our research suggests, is now taking shape globally, forming a global rank-order distribution of cities.
Functionally, what is happening is that certain key functions of the old national city-systems have been shifted up the chain. Chicago has indeed taken over financial, service, and professional functions from a whole host of second and third tier cities - Pittsburgh, Cleveland, Detroit, Milwaukee, Toledo, and so on. Washington DC has benefited from the same sort of trend, and is some ways has become a "suburb" of New York in providing these functions. Atlanta plays a similar role in the southeast.
But, as Brendan adds, the real question is that competition is growing throughout the global city-system. In other words, the same kind of dynamics that have confronted Pittsburgh and Detroit in the past several decades may some day come home to roost for Chicago. My team's analysis suggests that Chicago may have some real vulnerabilities. In contrast to New York, LA and San Francisco, which have real locational advantages in key economic sectors, our analysis of occupational clusters suggests that Chicago has few if any, other than those associated with O'Hare and air transport. For the time being, it has found a reasonably comfortable niche, providing regional services to its mega-region and serving as a regional talent magnet. But the laws of motion of global capitalism leave little doubt that sooner or later the ante on both of these fronts will be upped.