A friendly kerfuffle between Calculated Risk and Craig Kamman has come up and, with what I've read and know, I'll have to side with Craig on this one. Not only does his charts show more old timers participating in this economy, Bill's charts are projections from 2006 and 2002, not actual data.
Now, I am still willing to be corrected if somebody comes up with better data, but my anecdotal experience is confirmed with Craig's data, not Bill's. In my various dealings with people in the 60+ range, nearly ALL of them HAVE TO work past retirement because they did such a poor job saving for retirement (or impoversihed themselves naively paying for their children's worthless Bachelors of Arts in Lesbian Transgendered Turtle Studies). Additionally, this creates a traffic jam at the top and upper levels of management that chain effects down to the rank and file of employees. Without old timers retiring, there's no movement or advancement upward. They're log-jamming the careers of people below them, and ultimately, not allowing for any new hires or entry level positions. Inevitably this becomes more discouraging to the youth than the elderly and the youth are more likely to participate less in the economy, loweirng their participation rate. Plus they can always "live at home" while a 62 year old does not have the option of moving back in with his parents.
Until better data proves me otherwise, the drop in the labor force participation rate is largely due to younger people who can't find jobs in part because there are none and also in part because nobody hires people with Bachelors of Arts in Unicorn Sculpture. It is not due to the baby boomers retiring.