The numbers have been telegraphing this for months:
The wealthiest Americans, of course, are showing even more hustle than last year, giving it 118% in 2015; and the poorest Americans, of course, can't slack any more than they were already slacking. But we see a significant drop-off in hustle among the middle three groups, with an astonishing 18% plummet among the second quintile.
I haven't bothered to look into this but can only assume we'd see a similar story during most dips and recessions. The laws of capitalism are immutable, and when the economy has problems it's usually pretty obvious who's to blame.