In the CS department, Gortler said, the annual loss of one or two professors to sabbaticals causes anxiety over offerings.

"Every year there's a minor crisis to cover what we say we're going to cover," he said.

In addition, Pedersen said, Harvard professors have more extracurricular responsibilities than their counterparts at other schools simply because of their standing in the academic community.

"[Harvard faculty] do a lot of outside reviewing and peer reviewing," she said. "Our faculty have to play a leadership role in their fields."

According to English Department Chair Lawrence Buell, these expectations are especially apparent in the humanities.

"My colleagues...feel rather strongly burdened by the combination of needing to stay active and visible in the profession (as the university expects)," he says.

And for junior faculty, these needs are especially pressing since tenure decisions are largely based on being a major figure in the field, Pedersen says.