Being a Yale professor is a year-round job, but it only pays for nine months. One biology professor has a proposal to change that.

At next Thursday’s meeting of the Faculty of Arts and Sciences, a body of professors from the College and Graduate School, biology professor Joel Rosenbaum will propose to recalibrate faculty salaries on a 12-month scale, effectively increasing pay by 25 to 30 percent.

“Research is our number one job,” Rosenbaum said. “That’s why we’re here. And that’s a 12-month job.”

Rosenbaum said the change would give Yale an edge in attracting and retaining talented faculty. But while extra cash is always welcome, other professors said they believe the plan might be imprudent and, consequently, they expect the proposal to fail.

The proposed change’s exact cost, which was not immediately clear based on the available details, would certainly run up to at least $100 million annually. But Rosenbaum said cost calculations should come later, and, instead, what matters is whether the proposal is the right thing to do.

Provost Peter Salovey declined to comment, explaining that he would reserve judgment until hearing the details of Rosenbaum’s proposal at Thursday’s meeting. He said he expects a “robust discussion.”

Currently, professors’ salaries at Yale are set based on the nine months of the school year and distributed over all 12 months of the calendar year, a system in place at almost all private universities. But Rosenbaum said that system has not kept pace with the demands of a modern research university. The days when nine months of teaching were the heart of a professor’s work are over, he said. Today, professors seeking tenure dedicate themselves to the kind of research that brings fame to them and their institution.

Growth in the sciences has also changed the salary dynamic for universities, Rosenbaum said. Professors are allowed to earn the remaining three months of their salaries from other sources, such as federal research grants. But equivalent grants in the humanities are much harder to find, and lately, given the current economic climate, the funds available to scientists have tightened.

“To some people it seems anomalous that one part of the faculty is required to raise its own funds,” chemistry professor Michael McBride said, referring to the sciences. “On the other hand, the other part probably wishes they could do that also.”

Paying employees for all 12 months would compensate them for work they are already doing, Rosenbaum said.

Doing so would not deter professors from seeking grants, McBride said, because they would still be motivated to seek grants in order to make tenure and establish their scholarship.

“The reason is not to pay yourself — it’s to do your research,” he said.

Under Rosenbaum’s proposal, professors who earned the equivalent of their summer salaries through outside grants would have their University salaries for the period credited to their department.

But McBride does not expect the proposal to pass.

Neither does physics professor Douglas Stone, a former department chair and former chair of the committee on the economic status of the faculty.

University salaries are market-driven, Stone said, meaning they relate to salaries at similar universities. Yale’s are already among the highest in higher education, and suddenly raising them by a third would be “an odd move economically,” he said.

“For the level of excellence and dedication of our faculty, and the incredibly competitive selection they have gone through, market rate may not seem ‘fair’ compared to other professions,” he said in an e-mail. “But we all made that decision long ago.”

While many professors work very hard in the summer on a mixture of teaching, committees and research, the level of work varies by department and individual, Stone continued. So paying based on the assumption that everyone is working may not be justified, he said.

Employee compensation, including salaries, wages and benefits, comprise about 60 percent of the University’s operating expenses. The average salary of a Yale professor, excluding Medical School faculty, is $124,202.

At the meeting, Rosenbaum will ask the provost to appoint a committee to study how to implement the proposed change to 12-month salaries. The plan would then be put to a vote by the faculty and, if it passes, would be presented to the University president and the Yale Corporation.