Pittsburgh Peak Labor
Anyways... here is a far more interesting trend with the latest data appended.
The shift is that when you go back and look at October 2008 it was right in the middle of the AP-dubbed 'Great Recession'. So lots of anomalous things going on in a lot of regional labor markets that were probably inhibiting normal migration flows across the nation. Economic worries in a lot of places that were hit harder than Pittsburgh probably were not 'pulling' people from Pittsburgh at normal rates. People staying in place here, while others coming here from regions that were already seeing rapid job losses probably played into the labor force surge here at the time. 'Surge' relative to what Pittsburgh has normally experienced in recent years.
Now however, there has been a significant drop in the national unemployment rate and national job growth over the last year. In a lot of regions Pittsburgh normally 'competes' with for people and jobs the rebound has been significant. So the 'pull' of people and jobs elsewhere has probably started to return to normal levels. Yet there is no sign of a turnarourd in the upward labor force trend here. That really marks a different dynamic if these trends sustain themselves.
If recent labor force trends showing Pittsburgh comparing well to the nation were really mostly an artifact of the recession, then when the recession ended. you might expect things to revert for Pittsburgh. I was not expecting it because Pittsburgh's divergence from national trends began well before the recession even appeared, but it was something to watch for. For the moment the evidence is that Pittsburgh's trends were not a corollary of the recession. If the relative differences in unemployment rates (Pgh vs. US) continue, it bodes well for migration trends as reinforced by the labor force numbers. Little secret, but labor force participation rates do not jump around anywhere near as much as people think they do. Near term trends in labor force at a regional level is more impacted by workforce migration.