Re: The baby boomers retiring has a lot to do with it.
The “Not In Labor Force” percentage includes only Americans between 18-65.
Perhaps more Boomers retire early, but the percentage that get S.S. at age 62 has been steady for many years.
My own guess is that the size of the work force has disproportionately increased because of massive immigration, productivity has increased because of cell phones, expert software, robotics, etc., and government benefits are more plentiful and more generous.
I'm a boomer, retired on Friday. I'm 59. I did not live large, now I can up it a bit.