Does Science Promote Women?
A few months back I tracked down some statistics on gender ratios in science and engineering departments . I knew things were skewed, but even so, I found the data surprising: men outnumber women in tenured and tenure-track S&E positions by more than 3 to 1. There has been a good deal of recent effort in figuring out why, and we'll be writing more about the subject over the next few months.
Take a look at the stats disaggregated by academic rank:
| Rank | Male | Female |
|---|---|---|
| All ranks | 77% | 23% |
| Full professor | 86% | 14% |
| Associate professor | 74% | 26% |
| Assistant professor | 64% | 36% |
Is the skew in the top ranks simply the result of gender skew in the PhD pool decades ago? Or are women less likely to be hired into tenure track positions and promoted to tenure as a result of discrimination?
A new paper, "Does Science Promote Women? Evidence from Academia 1973-2001" by Donna Ginther and Shulamit Kahn provides some interesting answers.
Ginther and Kahn use data from the NSF's Survey of Doctorate Recipients (the SDR) to estimate the chances of obtaining a tenure track position and of subsequent promotions as a function of sex and other explanatory variables. The SDR is a huge, longitudinal survey that covers about 10% of all US PhD holders, and it provides a great resource for addressing these kinds of questions.
Their findings, in a nutshell:
- Overall, women are less likely to obtain tenure track positions in the sciences
- However, the gap is entirely explained (in a statistical sense) by marriage and children.
- Furthermore, there is little sex-related difference in the likelihood promotion to tenure or full professor.
Some key findings:
For women, having a child under age 5 lowers the probability of a tenure track appointment by 8%. Children in grade school have no effect.
In contrast, for men, children under age 5 have no effect, while each child in grade school increases the probability of a tenure-track job by 3%.
These results are consistent with Mason and Goulden's work. A few possible (non-mutually-exclusive) interpretations:
The probability of a tenure-track position increases (up to a point) with time past PhD. Time off for maternity leave shifts the clock back for women. Perhaps the gap would be smaller if one compared the probability of tenure at 5 years for men with young children to, say, the probability at 5.5 years for women with young children.
Several studies have documented that women scientists with young children spend fewer hours in the lab than their male counterparts, presumably because they bear the brunt of childcare responsibilities. Perhaps this results in fewer publications and consequently reduced competitiveness for tenure track positions. Interestingly, Anne Preston has found that "those male scientists who do childcare have similar impacts on their academic careers".
There is often an implicit assumption that an academic position is the only desirable outcome for a PhD scientist. Perhaps women with children see that academia (particularly postdoc-docm) is not a particularly hospitable place and seek greener pastures in industry. Anne Preston has found that "a major reason that women leave science is because of childcare responsibilities."
A couple of other less central but still interesting results:
On average, a single childless woman is substantially more likely to get a tenure track jobs than a single childless man. The gap is 21% in the physical sciences, 11% in the life sciences, and negligible in engineering.
Marriage increases the probability of a tenure track job for both men and women, but it helps men much more than it helps women (22% increased probability for men vs. 5% for women). On the balance, men and women who are married and childless have about the same chance of obtaining a tenure track position.
The authors posit that these differences are the result of "selection effects", i.e. the populations of unmarried men and married men are differ in ways other than just marriage. They suggest that "'good catches' in the marriage market are correlated with 'good catches' in the labor market." They don't speculate on possible reasons for the gender asymmetry; I'd guess that it's partly due to the fact that that men are more likely to have stay-at-home spouses than women.
Marginal Revolution categorizes the paper as the "politically incorrect paper of the month". My take, however, is more in line with that of Matthew Yglesias: at least part of the reason for gender differences in the sciences is that academic careers are structured in a way that makes things particularly difficult for women who have young children early in their careers. On the plus side, once women achieve tenure-track positions, they appear to be just as likely as men to be promoted to tenure and to full professor (though, as Ginther has documented in prior papers, their pay lags that of their male counterparts).
The good news is that a few institutions are starting to rethink the way they handle faculty family issues and are making improvements. I'll talk about some innovations in a future post.
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on Tue, Nov 21, 03:11PM
Geoff,
The Wall St Journal had an article in yesterday's paper (In the Lead: Women Tell Women - Life in the Top Jobs is Worth the Effort - by Carol Hymowitz, Nov 20, 2006 p. B1) about a panel discussion with 5 top female CEOs and business leaders. I bring this up because the challenges facing women on the tenure track are probably not too dissimilar to those of women on the executive track. Probably a lot of the same factors (childbearling/rearing, famly support) apply in both worlds.
Several interesting comments came out of the panel discussion. First - these women suggested that the word "balance" should be banned from women's vocabularies. According to the panelists, balance = perfection which nobody can achieve, so rather than live with the stress and guilt, accept that sacrifices will be needed on both sides. The women on the panel expressed the concern that the fears some young women have about having an imbalanced work/life situation may cause them to "waive the white flag" before they've even gotten into the game. One of the panelists commented that people can be lonely, get divorced or have troubled kids without having a great career - "so why torpedo your chances of success before you've even tried?"
The reason I bring this panel discussion up because I think that the entire debate about women in academia tends to be somewhat myopic. Most PhDs (men AND women) don't end up in academia. There are lots of good reasons for this: the job is hard and, despite what most graduate students are brainwashed into believing, is probably genuinely rewarding for only a subset of the folks who enter graduate school. During my grad school experience the most common career concern among my fellow grad students was the fear that they'd have to live a life like their advisors!
Everyone on the panel noted that they were sustained in what they did by passion and love of the industry or the subject that was at the heart of their job. If we explored these deeper "satisfaction" issues while in graduate school, we PhDs would probably feel more satisfied with our careers , no matter what pathway we took.
My $0.02
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on Wed, Nov 22, 12:11PM
You make a good point about the discussion of women in science being overly focused on academia. I like Philip Greenspun's perspective: there are fewer women in academic science jobs because they choose to get better jobs elsewhere. The biggest loser in all of this is academia itself.
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on Tue, Nov 28, 09:11PM
Re Greenspun’s Perspective
I agree that academe is not particularly attractive these days. However, if Greenspun gave any statistics indicating that a higher percentage of women than of men go into industry, I missed them. From Scarcity to Visibility suggests it's not the case (see p. 104), at least up to 1995. It certainly might be that things have changed since.
Several years ago, I looked at From Scarcity to Visibility and picked out pieces of interest to me. For Ph.Ds. surveyed in mathematical sciences, in 1995:
• Approximately the same proportion of men and of women had full time academic jobs (p. 127).
From Scarcity to Visibility concludes (about science in general):
• The transition from the Ph.D. to the full-time labor force is a critical point at which relatively, more women than men are lost (p. 221).
• Throughout the career, proportionally more women than men leave science and engineering entirely (p. 221).
Long, J. Scott. (Ed.). (2001). From Scarcity to Visibility: Gender Differences in the Careers of Doctoral Scientists and Engineers. Can be read on the Web Washington, DC: National Academy Press.
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on Wed, Nov 29, 01:11PM
Interesting observations, Cathy.
In my (quick) read of the tables in chapter 5 (e.g. page 105) one other thing stood out: a larger fraction of women than men are in academic positions, at least through 1995. The data aggregate everyone who received a PhD from 1970 or so through 1995, and a lot has changed over that time period (though not necessarily the ratios in question). I'd be interested to see some individual cohort data for more recent graduates.
I tried to find further information on the two summary points you cite from page 221. It looks like the main supporting data for the first point (more women than men being "lost") has to do with the 1970 and 1973 PhD cohorts (e.g. pages 78 and 86). I'd be surprised if the differences were still that big for recent cohorts. Interestingly (at least to me) is that the differences in the percentages out of science are not actually all that big in some fields (e.g. math, life sciences, p. 78). The real story is differences in those working part-time or not at all. Judging from p. 90 and onwards, those differences have mostly to do with young children and cultural expectations for who cares for them.
Looks like I need to dig into this report at some point.
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on Wed, Dec 13, 04:12PM
Ginther and Kuhn Very interesting article by Ginther and Kuhn. However, I wish they had categorized the institutions at which tenure occurred. Not all tenured positions are created equal, at least in my opinion.
In mathematics departments, tenure-eligible college faculty members are 31% female, other full-time faculty members are 47% female, and tenured faculty members are 17% female (Lutzer, Maxwell, & Rodi, 2002). It’s certainly possible that some of the “other full-time faculty members” don’t have PhDs.)
In the “top 10” mathematics departments, there are approximately 300 tenured faculty members; 16 of them are female (Jackson, 2004).
Women do earn PhDs from “top ten” departments though. For example,
"In mathematics, UC hired 5.4% female faculty, the national Ph.D. pool is 22.1%, UC graduates 18.4% female Ph.D.s, our comparable institutions graduate 19.6% women Ph.D.s and even the postdoctoral pool (which in mathematics is highly competitive and is an indication of potential for future funding) has 13.2% females in it." Testimony of University of California Chancellor M. R. C. Greenwood on 1/31/01)
In particular, between 1993 to 2003 the mathematics department at Berkeley hired 28 faculty members. None was female. I haven’t checked recently, but after 2003, a woman got a joint appointment in physics and mathematics.
As of May 2006, there has never been a tenured or tenure-track female mathematician in the Harvard mathematics department (Silverberg, 2006)--and it may still be the case.
However, the situation at elite universities may be quite different in physics. The percentage of women getting PhDs in physics is much lower than in math, for example, 18% of physics PhDs went to women in 2003. (It's been around 30% for mathematics, I'm not sure where Greenwood's statistic came from in the quote above.) The American Institute of Physics survey seems to have gotten results similar to that of Ginther and Kuhn with respect to rate of tenure. The following comes from an (FAQ for this survey)[http://www.aip.org/statistics/trends/reports/womenfaq.htm]:
Q: What about women at the top physics departments? Perhaps women can get faculty jobs, but not at the elite departments.
A: Women can, and do, get jobs at elite departments. Among the top 20 departments (using NRC rankings), 6% of the full professors are women, 11% of the associate professors are women, and 12% of the assistant professors are women. These percentages are also consistent with degree production in the past, meaning that women are represented on the top 20 faculties at about the levels we would expect.
References
Jackson, A. (2004). Has the women-in-mathematics problem been solved? Notices of the American Mathematical Society, 51(7), 776–783.
Lutzer, D. J., Maxwell, J. W., & Rodi, S. B. (2002). *Statistical abstract of undergraduate programs in the mathematical sciences in the United States. Fall 2000 CBMS Survey.* Providence, RI: American Mathematical Society.
Silverberg, A. (2006). Women at Harvard. Association for Women in Mathematics Newsletter, 36(3), 17–19.
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on Wed, Dec 13, 05:12PM
A very interesting point, Cathy! I seem to remember that somewhere in the Ginther & Kahn paper there is a brief aside to the effect that things might be tougher for women at top-tier institutions, but I'm not sure they looked at the issue in detail. You might ask them (I don't know Ginther, but have met Shulamit Kahn briefly, and she seems like she'd be amenable to such questions). I would speculate that the impact of children would be the greatest at institutions that are the most demanding of people's time and energy. However, family issues don't really provide a very good explanation for your observations about Berkeley and Harvard.
Ginther and Kahn are looking at data across all institutions and disciplines; I could certainly see that there might be some interesting non-uniformity once you get to the level of individual departments. I think that people tend to hire / associate with people similar to themselves, so perhaps all-male or almost-all-male places need a bit of leadership (or a kick in the pants) to get with the program.
If it is in fact the case that there is a bit of an old-boys network still at some places, one upside is that as the ranks of women increase, these problems will presumably decline and the resulting virtuous cycle will further accelerate the pace of hiring of women faculty members.
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