What's not in dispute: the sheer size of the aging baby-boomer generation and that an unprecedented demographic shift distorts statistics. It means, for instance, that retirees can play a significant role in the shrinking labor force even as people are staying on the job longer than ever.
The U.S. jobless rate fell below 7 percent at the end of last year for the first time since 2008, helped by an exodus of retirees that has shrunk the labor force, Fujita wrote in his analysis, revised in February. Unemployment dropped even further in April, to 6.3 percent.
Those numbers dovetail with the broader economic recovery, prompting Drew Matus, deputy U.S. chief economist at UBS Securities LLC, to posit that boomers put retirement plans on hold during the depths of the financial crisis and have been revisiting those plans since.
Baby boomers were born between 1946 and 1964, when a jump in birth rates followed World War II. As each year passes, the demographic inches along into older age slots that naturally have lower workforce participation.
Stock market gains haven't helped everyone. Those who want a job but have given up looking reached 783,000 in April, almost triple a low in 2007. That figure has remained stable since the beginning of 2012, ruling it out as a key factor behind the drop in participation rate, Fujita said.
Most economists agree that boomers will drive declines in the labor force for years to come. The Bureau of Labor Statistics projects that the aggregate participation rate will be 62.5 percent in 2020, 1.8 percentage points below the level in 2010.