²ÝÁñÉçÇø

Once, being a college professor was a career. Today, it's a gig.

That, broadly speaking, is the transformation captured in the graph below from a new report by the American Association of University Professors. Since 1975, tenure and tenure-track professors have gone from roughly 45 percent of all teaching staff to less than a quarter. Meanwhile, part-time faculty are now more than 40 percent of college instructors, as shown by the line soaring towards the top of the graph.