Honey, I shrunk the middle class

The definition of middle class jobs is arbitrary and not particularly good. From the NYTimes story, it seems it's basically wages between 35 and 100k per year. At any rate, less jobs in manufacturing and more in services, particularly in health jobs, like nurses. Also, a gender bias, with an increase in female participation in the middle income jobs. And yes, increasingly these jobs require a college education. So more nurses and less machine operators, or something like that. The problem is that with this the size of the middle class is effectively shrinking (see graph below).

This suggests that the majority in the US is not middle class anymore. The divided society between the haves and have nots is becoming the defining characteristic of the US.