While the proportion of women receiving tenure-track offers to join Harvard University’s Faculty of Arts and Sciences rose for the third straight year in 2005-6, the share of women who accepted positions declined dramatically, according to an internal report.

In what the report's author calls a "troubling reversal," slightly more than 20 percent of those who accepted tenure-track offers in Harvard's main undergraduate college last year were women, down from 40 percent in 2004-5. Thirty-nine percent of tenure-track offers were to women last year.

Women have tended to accept Harvard’s offers at a higher rate than men over the past few years, according to the report, but not so last year.

“It's surprising that at the tenure-track level, we had a hard time recruiting women last year," said Lisa L. Martin, the report's author and a professor of international affairs.

A year ago, Martin was named senior adviser to the arts and sciences dean on diversity issues. The findings on women's offers and acceptances come from her first annual report, delivered to the college's faculty last week.

The report does not specify exactly how many women accepted Harvard's offers last year but sheds light on a university that has publicly dealt with the issue of female faculty. Early last year, then-president Lawrence H. Summers suggested in a speech that one reason there are relatively few women in top positions in science may be “issues of intrinsic aptitude." The comments created considerable controversy that many say contributed to Summers's downfall.

Martin said it is hard to say what kind of effect the Summers controversy had on the recruitment of women at Harvard.  

The report shows that Harvard continues to have trouble recruiting female faculty members in the humanities. Roughly 35 percent of humanities tenure-track faculty are women, even though the proportion of Ph.D. earners in those fields who are women is well over 50 percent.

Since female faculty recruitment at Harvard generally improved in the 1990s, Martin said complacency has probably been a factor. "A lot of people thought there wasn't a problem anymore," she said. “What this report drives home is that the hiring of women is an issue that requires constant attention."

Regular factors such as cost of living and family obligations might have deterred some women from accepting tenure-track offers last year, Martin said. The report shows that a growing number of faculty members live outside of Cambridge, and that women said having to leave early from faculty meetings to commute home was an issue. Martin said it is unlikely that faculty members decided to accept jobs at other Ivy League universities en masse, because the competitors see similar numbers.

She added that the data are from early summer, meaning that some female faculty members were still making up their minds. "It's just one year, and it's too early to call it a trend, but this is something I want to flag," Martin said.

Added Jane Mansbridge, a professor at the Kennedy School of Government: "It's too early to tell if the failure of more women than usual to agree to come to Harvard last year was the result of specific historical circumstances, continuing problems (e.g., finding jobs for spouses), or a statistical random blip in the data. If the trend continues, we will have fairly good evidence that the cause is some combination of continuing structural problems. But at the same time the faculty and deans of the schools will be taking steps to try to resolve those continuing problems. So we may never have a precise analysis of the cause."

Harvard has already announced efforts designed to turn around the female acceptance numbers. Among them is a new policy that allows mothers in the arts and sciences college an eight-week maternity leave coincident with giving birth -- which exceeds the guidelines for maternity-parental leave announced by the senior vice provost this year. Academic departments are also taking part in a mentorship program that pairs tenured female faculty with women in tenure-track positions.