The Faculty of Arts and Sciences has experienced nearly a decade of overall faculty growth, but its subset of junior faculty has dramatically fallen in the last two years—partly due to reduced hiring in the wake of the financial crisis.

The number of junior faculty—professors who are eligible for promotion to tenure—increased in proportion to the overall FAS faculty throughout the early 2000s. But the cohort of junior faculty decreased from a stronghold of 207 in 2006 to 178 members today, according to the FAS Dean’s Annual Report released last week.

In contrast, the University’s largest school has expanded its overall tenure-track and tenure faculty from 701 in 2006 to 721 members today. The FAS faculty has grown about 16 percent over the past decade alone, the report shows.

FAS administrators and faculty members partly attributed the lacuna in the junior faculty to the slowdown in hiring instituted in response to the financial crisis that rocked the school for the past few years. In Dec. 2008, FAS announced a hold on a bulk of current searches for tenure-track and tenured faculty as part of cost-cutting measures.

According to the report, recent hires have not kept pace with the usual attrition to the ranks of junior faculty, including departures and promotion to tenured positions within the school.

But the FAS ratio of junior to senior faculty is considerably smaller than that at peer institutions. Junior faculty at FAS compose about 25 percent of the tenure-track and tenured faculty.

At Yale, for instance, junior professors compose about 36 percent of its tenure track and tenured faculty in the arts and sciences as of last fall. At Princeton, 34 percent of the tenure track and tenured faculty are junior professors.

Over the last decade, FAS and the University as a whole have emphasized  the tenure track process at an institution that has traditionally focused on drawing experienced academics from outside Harvard and hiring them to tenured positions.

History Professor William C. Kirby served as the dean of the Faculty of Arts and Sciences when the school transitioned to a tenure-track system in the early 2000s.

“I don’t think there is a magic ‘formula’ or ratio between tenured and untenured faculty,” he said in an e-mail statement. “But again: a strong and sizeable cadre of assistant and associate professors is in my view essential to the academic excellence and vitality of the Faculty of Arts and Sciences.”

The social sciences division in FAS has experienced the most significant drop in junior faculty numbers, according to Organismic and Evolutionary Biology Professor Elena M. Kramer, who spoke at last week’s Faculty meeting on behalf of the Standing Committee on Women, which conducted a year-long review of the hiring and promotion process.

In the History Department, less than 15 percent of the faculty listed on the department website—or six of the 48 tenure-track and tenured professors—are junior faculty. Two are on leave for the current semester.

“We are weaker in several fields than we would like to be,” James T. Kloppenberg, chair of the history department, wrote.

“Of course Harvard will continue to appoint very distinguished senior faculty, a step that is important to maintaining our standing,” he wrote.

“But we must also continue to appoint junior faculty, who bring energy and new points of view,” he added.

—Staff writer Noah S. Rayman can be reached at nrayman@fas.harvard.edu