I will boil the facts down to some easy to comprehend statements. All of these are supported by evidence in the OP. Links a-plenty.
1. The participation rate for people over 55 has been going UP, not down. That includes the over-65 age group. UP, not down.
2. The participation rate for educated people is HIGHER than for less educated people.
3. The participation rate for people under 55 has been doing DOWN.
4. The participation rate for 16-24 age group has experienced a particularly LARGE DROP.
5. This has been occuring since before anyone even heard of Barack Obama.
1. That is because the total population of people over 55 has been going up!
3. That is because the total population of people under 55 has been going down!
4. That is because the birth rate has declined after the Boom years.
Which means the retiring Boomers is the single most factor for the decline in LPR since 2008.
It's not totally bs. But, yes, given the increase in overall population % being oldsters that is occurring, simply showing an increase in the LFPR by oldsters cannot mean that retirements are not having a increasing effect on LFPR.
However,
http://www.ebri.org/pdf/notespdf/EBRI_Notes_04_Apr-14_LbrPart.pdf
Regardless, two results are clear from the data.
First, the labor-force participation rates of younger workers increased when that of older workers declined or
remained low during the late 1970s to the early 1990s, but as the labor-force participation rates of younger workers
began to decline in the late 1990s, the rates for the older workers continuously increased (Figure 9). Consequently, it
appears either that older workers filled the void left by younger workersÂ’ lower participation, or that higher olderworker
participation limited the opportunities for younger workers or discouraged them from participating in the labor
force.
Second, the percentage of older workers increased steadily from 1997 to 2012, while the percentage of younger
workers declined during this period (Figure 10). In 1997, workers ages 25–54 accounted for 83.9 percent of all
workers ages 25 or older, while those ages 55–64 accounted for 12.0 percent, and those ages 65 or older, 4.1 percent.
By 2012, those ages 55–64 represented 19.2 percent, and those 65 or older 7.0 percent, while the percentage
of workers 25 or older represented by those ages 25–54 had fallen to 73.8 percent. Again, these concurrent trends
raise the question: Are older workers filling the void or displacing opportunities for younger workers?9
Still, an earlier link I put up suggests that while the overall LFPR will continue to decline, at least in part to oldsters retiring, younger workers should leave school to take jobs as the overall employment market eases.
Goldman On The Labor Force Participation Rate - Business Insider
As for disability, if you're an older worker who loses a job, disability is attractive, and the older you get pre 67, the more likely you have something wrong with you. If you keep your job, there's little incentive in disability because it pays less than a job. The numbers are up. Whether we are more disabled or not is questionable.