Why doesn't U.S. economic expansion 'feel' like an economy is at full employment? Because of the low participation rate that has effectively reduced unemployment to superficially low levels without creating sufficient amount of quality jobs to offset the rise in working age population since the end of the Great Recession.
Here is a chart, via @ernietyedeschi, showing that the U.S. economic expansion has only recently started reducing the sticky non-participation drivers that remain in play since 2001:
The above is a fundamental problem for a range of advanced economies, not just the U.S. as I have noted in a number of previous posts, as well as a factor related to the secular stagnation thesis on both, demographic side (demand side secular stagnation) and technology / wages side (supply side secular stagnation).
