Class ends. Students pack up and head back to their dorms. The professor, meanwhile, goes to her car...to catch a little sleep, and then eat a cheeseburger in her lap before driving across the city to a different university to teach another, wholly different class. All for a paycheck that, once prep and grading are factored in, barely reaches minimum wage.

Welcome to the life of the mind in the gig economy. Over the past few decades, the job of college professor has been utterly transformed - for the worse. America's colleges and universities were designed to serve students and create knowledge through the teaching, research, and stability that come with the longevity of tenured faculty, but higher education today is dominated by adjuncts. In 1975, only 30 percent of faculty held temporary or part-time positions. By 2011, as universities faced both a decrease in public support and ballooning administrative costs, that number topped 50 percent. Now, some surveys suggest that as many as 70 percent of American professors are working course-to-course, with few benefits, little to no security, and extremely low pay.

In The Adjunct Underclass, Herb Childress draws on his own firsthand experience and that of other adjuncts to tell the story of how higher education reached this sorry state.