From Leaving the Academic Stage by Robert Zaretsky.

According to a 2014 report and survey from TIAA-CREF, scarcely a fifth of workers in most professions are 55 or older. The one exception is higher education, where a full third of faculty members fall into that age cohort. That disparity, warns another study, will deepen with time: 60 percent of my colleagues intend to remain in the classroom when they pass 70, and 15 percent say they will hang on until they are 80.