You know, I spent some time in college learning economics, and lots of time after that listening to podcasts about economics ("Planet Money" has long been great), but like almost every other belief I had when I was younger, I seem to have lost this one as well.

Supposedly we've had decades of productivity growth, so you'd think that it would be possible for a smaller cohort of workers to keep everything going, and yet it is apparently a creeping disaster that there may not be enough of them to maintain modern civilization in the not-so-distant future. Like many aspects of modern life, it just isn't really adding up to me.