Chris Briem can supply details (and better hypotheses), but I was struck by this piece from the current Economist. Out in California, relative economic calm is associated with communities that are, on the whole, older than the norm:
Nowhere in California is immune to recession, but the oldest areas are proving most resistant. Of the ten counties with the lowest unemployment rates, nine, including Santa Barbara, contain an above-average proportion of people aged 65 or older. Youthful Los Angeles has shed almost a quarter-of-a-million jobs in the past year. Slightly older San Diego has lost a few thousand, while considerably older San Francisco has lost none. A map of the state’s retirees (see above) could almost double as a map of economic resilience.
Allegheny County's population is notorious for skewing older. In the conventional (dare I say Floridian?) wisdom of the last decade, that fact is often cited as an obstacle to growth. There is much more to be said on the topic, but is it possible that Pittsburgh's stodginess is now its greatest asset?