If we created three kinds of tenure rather than one, we might see net gains in both research and teaching.

A research-only tenure track would be for professors who have the passion and talent for discovering knowledge, but lack the motivation or ability to teach well. This would allow them to do more groundbreaking studies and produce more patents, while sparing students the sorrow of shoddy courses.

Creating more full-time research professorships could combat the decline of research productivity post-tenure, as many productive professors see their nonteaching time consumed by administrative responsibilities. If research professors didn’t teach, administrative duties wouldn’t impede their work.

A teaching-only tenure track would be for professors who excel in communicating knowledge. Granting tenure on the basis of exemplary teaching would be a radical step for research universities but it might improve student learning. In a recent landmark study at Northwestern, students learned more from professors who weren’t on the tenure track. When students took their first course in a subject with a professor who didn’t do research, they got significantly better grades in their next class in that subject.