Excellent analysis of what Americans who are not full-time employees are doing with their time... and the picture is not nearly as dire as some would have you believe.

Thank you for these facts that speak to an oft-quoted talking point.

There are many more disabled people than I realized and fewer people who want a job than I realized. 

OK but the disabled part is a little bit complicated. From everything I've read, there are a lot of people who worked physically-demanding jobs who get injured and cannot for whatever reason retrain for a desk job. Often they also live in areas that are economically depressed -- therefore cheap to live in, but lacking in jobs and education. Do they really WANT to be on disability, or is that large number an indictment of American opportunities in midlife?

Oh, and early "retirement" via disability is like the #1 cause of having low savings in old age.

I believe most people don't want to be on disability. 

I believe most people want to work, as pointed out here too:

http://pandawhale.com/post/68658/after-years-out-of-a-job-older-workers-find-a-way-back-in

 I'll just put this here...

http://www.theonion.com/article/unemployed-detroit-resident-dismayed-to-learn-job--34979

Yeah, nobody wants to work for the Lions.

DETROIT—Uttering an audible sigh of frustration as he noticed the franchise’s name in the classified ad, unemployed Detroit resident Chris Segel, 34, reportedly expressed disappointment Friday upon realizing the job opening he’d been considering was with the Lions. “Aw man, I was actually excited about this, but just when I got my hopes up I saw it’s for the goddamn Lions,” said Segel, who dejectedly confirmed after scanning the listing a second time that the facilities management position was definitely at Ford Field with the Detroit Lions. “I mean, I guess I’m applying anyway because it’s a job and I need one, but Christ, this market really is fucking brutal if this shit is all that’s left right now.” At press time, sources reported Segel was eagerly looking into a possible job opportunity with Detroit’s sanitation department.

This is just propaganda.  If disability explains away all the unemployment, what explains why disability claims rose 50% in the wake of the 2008 recession and have stayed there? 

You're right that both sides have their talking points but even the WSJ is now downplaying the unemployed, underemployed, and those on disability:

http://blogs.wsj.com/economics/2015/11/06/the-october-jobs-report-in-12-charts/

School, taking care of family, and retirement also account for a lot of the unemployment.

There are some demographic reasons apparently: Baby Boomers getting sick, and veterans coming back from the wars with more disabilities (including PTSD) in particular. But yes there are also people with weak job skills or Boomers who lost their jobs during the recession and now are unable to get another one even in a stronger economy.

http://money.cnn.com/2013/04/11/news/economy/disability-payments/index.html

This is pretty fair explainer on U.S. employment:  https://www.washingtonpost.com/news/wonk/wp/2015/11/06/ed-lazear-this-is-the-real-unemployment-rate/

No wonder I've been so confused by this talking point: Both the unemployment rate AND the employment rate are down.

The peak pre-recession employment rate was 63.4 percent. Correcting for hiring and demographics makes September's rate of 59.2 equivalent to a pre-2009 rate of 61.4 percent, meaning we still have a 2 percentage point deficit when compared with the earlier peak. This amounts to about 4.8 million jobs. Put differently, the number employed has grown almost 13 million jobs since the employment trough in February 2010. But it would have to have grown by 17.5 million to make up for the recession and keep pace with growing population.

We have come back considerably from the depths of the recession that began almost eight years ago. Unfortunately, we still have a way to go. Given conditions that are consistent with an unemployment well above 6 percent -- and not a 5 percent unemployment rate -- it is no surprise that many in this economy still feel that we are not firing on all cylinders.