Statistical noise and labor force math
The state reported yesterday that the unemployment rate in the Pittsburgh MSA dropped by a tenth of a percent from 7.2% in March to 7.1% in April. Note that the Pittsburgh MSA is in its entirety made up of 7 component counties. The unemployment rate changes in each of those counties is as follows:
Allegheny - increased 2/10ths of a percent
Armstrong - stayed same
Beaver - increased 2/10ths of a percent
Butler - increased 3/10ths of a percent
Fayette - increased 1/10ths of a percent
Washington - increased 2/10ths of a percent
Westmoreland - increased 2/10ths of a percent
Hmmm..... I don't think I could devise a weighting scheme that makes all that consistent without violating a fixed point theorem of some kind somewhere. Yes, there is an explanation of sorts for it all, but why try to rationalize?
OK, ok.... not to get into it too much, but it all is saying that the seasonal adjustment factors used by the federal wonks are so different from the seasonal adjustments made by the state wonks that the region's unemployment rate could differ by as much as 3/10ths of a percent between them. Compare that to the punditry and parsing based on on monthly changes of just 1/10th or 2/10ths of a percent.