In order to determine why there has been in an increase in the labor force participation rate in recent months, the Atlanta Fed breaks down data on shifts in age as well as results from changes in behavior. The Atlanta Fed found that the 0.22 percentage point dip in participation due to an aging population was offset by a 0.23 percentage point decline in those who wanted a job but did not count as unemployed.
This latter category, if it grows at its current pace, could reach pre-recession levels in about a year:
Despite the recent uptick, projections over the next decade or so have the labor force participation rate moving lower, chiefly because of an aging population. But how much farther participation actually declines will also depend on the evolution of various behavioral factors.