Last summer, as her 45th birthday approached, Melissa Bruninga-Matteau made a promise to “end part of her life.”

She had earned a Ph.D. in medieval history—from the University of California at Irvine, after nearly a decade of study—back in 2011, and she had hoped to glide into a solid faculty position. Instead, the previous two years had been marked by disappointment, depression, and rejection. Though she had applied for more than 100 teaching openings, nothing much had panned out. The best job she’d been able to find was as an adjunct at Yavapai College, a community college in Prescott, Ariz., where she taught a couple of humanities courses for meager pay and no benefits.

Bruninga-Matteau ended up relying on food stamps and Medicaid, barely scratching out a living for herself and her 17-year-old daughter. When she wasn’t grading papers, or worrying about keeping the lights on and the hot water running, she was trawling the Web in search of articles about the brutal academic job market and colleges’ use of adjuncts.

“It was just all so depressing,” she says. “If I was ever going to provide for myself and for my daughter, I needed a job with decent pay and benefits.”

So Bruninga-Matteau told herself that if she didn’t land a tenure-track job—somewhere, anywhere—by her birthday, June 11, she was going to give up on her dream of becoming a history professor and move on from that chapter in her life....