Still Not Much Of A U.S. Employment Recovery
Some argue that it is misleading to view the drop in the participation rate as an increased in "hidden unemployment", people who want a job but don't think they have any chance of getting one so they have stopped sending in applications. Instead they think it reflects the retirement of "baby boomers". But while the increase in the number of retirees has indeed lowered the participation (and employment) rate, this has to a large extent been offsett by a drop in the number of 15-24 year olds. 15-24 year olds also typically have lower employment rate because so many of them are students.
If you look at the employment rate for "prime age" workers, 25-54 year olds, then you can see that it has developed only slightly less bad than the overall 15+ ratio.