Lesley University professor Matt White. (WGBH/Kirk Carapezza)

Part-time professors at Lesley University in Cambridge have overwhelmingly voted to form a union. Lesley is the latest in a growing number of schools to unionize its part-time instructors.

Adjuncts make up more than half of all college professors in America, many of them earning just a few thousand dollars per course. Lesley depends on nearly 700 adjunct professors. Monday’s vote allows these part-time faculty to collectively negotiate their pay and benefits.

Adjuncts at Lesley want higher salaries and a contract that guarantees they are going to teach regardless of enrollment.

Joseph Moore, Lesley’s president, said that while he knows the new collective bargaining contract will change the way his institution operates, the school is prepared to negotiate with labor leaders.

“I think nationally there are some indicators here that institutions have been relying more and more on adjuncts,” Moore said. “There’s pretty clear data on that. So I think historically, if you look at the evolution of American higher education, it's a time to address the issues.”

That increasing dependence on part-time faculty has emerged as a major flashpoint, with colleges being criticized for devoting too much capital to research and development rather than teaching. On average, about one third of college budgets is spent on actual instruction.

Lesley University president Joseph Moore. (WGBH/Mallory Noe-Payne)

Matthew White teaches at Lesley’s school of art and design. He says the vote is a big victory for adjuncts.

“We’re really excited that we have such a strong voice to move forward and to think about how we can better ourselves and better our students and make the university stronger,” White said in a phone interview.

Lesley joins only Tufts University, which back in October became the first Boston-area school to organize its adjunct faculty under the Service Employees International Union.

In December, WGBH's On Campus reported on the movement to unionize adjunct faculty. Listen to that story here: