Edward Glaeser does some speculating as to how the economic shock might drive migration. I submitted a reaction to New Geography, which may or may not publish it. So, I'll tap the words of Ryan Avent as a way to enter Glaeser's observations into my blog record:
Unsurprisingly given the sectoral bias of the recession, low unemployment is strongly correlated with the stock of human capital. Glaeser notes that low unemployment in this recession is actually correlated with the stock of human capital in the 1940s, which mainly shows the persistence of concentrations of human capital. As he has noted in previous research, human capital levels have actually diverged over time, with smart cities getting smarter and vice versa.
The story of shrinking cities is one of brain drain, the out-migration of human capital. The Rust Belt is full of dumb cities getting dumber. Glaeser's conclusion:
During the recessions, thousands fled the Dust Bowl. In the 1970s and 1980s, there was a massive exodus from the Rust Belt. Today’s recession will also prompt mobility, probably toward more skilled, more centralized cities with less historical commitment to manufacturing.
I think this bodes well for Pittsburgh. Surprisingly, the Steel City is a smart city getting smarter. Quoting Bill Testa:
In considering educational attainment of the populations, the [table below] displays the ranks of Great Lakes metropolitan areas among 118 metropolitan areas in 1970 and 2006. The two local leaders in 1970 college attainment, Columbus, Ohio, and the Twin Cities also experienced the fastest employment growth. While Pittsburgh ranked low in college attainment in 1970, its gains in this metric since then have been the most rapid. Perhaps not accidentally, Pittsburgh’s growth in per capita income also outpaced other cities in the region.
As good as that might make Pittsburghers feel, it hasn't translated into population gains via migration. However, I don't think something structural is keeping Pittsburgh from growing like Glaeser might expect. Unemployment is relatively low and Pittsburgh may be on the cusp of getting on the mental maps of talented outsiders. It all depends on the region's ability to shake its "historical commitment to manufacturing."