In yesterday's post about the lack of money in academia, I mentioned in passing that lack of funding is part of the reason for the slow pace of progress on improving faculty diversity. That is, we could make more rapid progress if we suddenly found shitloads of money and could go on a massive hiring binge, but in the absence of flipping great wodges of cash, change comes more slowly.
This, naturally, sparked a sort of morbid curiosity about whether the scale of this problem would be quantifiable, and of course, there's the AIP Statistical Research Center offering numbers on all sorts of features of the physics landscape. So, here are some numbers about what it would take to achieve equal representation for women within physics departments. These are grabbed from reports spread over a few years, so I'm going to aggressively round numbers, usually up, because the goal here is just to give a sense of the scale, not a precise prediction of anything.
So, according to a recent-ish report on the number of faculty jobs (pdf) there were about 9,400 physics faculty in the US, and 80% of those are on the tenure track. From the report on women in physics (pdf), about 14% of those are women.
Aggressively rounding these, that's 7600 tenure-track faculty, 6500 men and 1100 women. Which means we'd either need to replace 3700 men with women to achieve the goal of equal gender representation, or create 5400 new faculty positions to be filled exclusively with women.
Assuming this replacement were to take place via the normal retirement/replacement process, how long would that take? Well, the AIP has a report on faculty turnover (pdf), which suggests we could ballpark the number of jobs on offer in a given year as about 600. Which means it would take a bit more than six years of exclusively hiring women into physics faculty lines to get to equal representation.
Leaving aside the massive legal issues with such a program, is that even feasible? Well, the report on graduate degrees (pdf) says that in recent years there were about 1900 Ph.D.'s in physics awarded per year, and around 20% of those went to women. Which we can aggressively round to about 400 women per year, so the "hire only women" plan would require hiring half again as many women per year as graduate with a Ph.D. in physics. If you just hired every woman who got a Ph.D. directly into a faculty job, it'd take a bit more than nine years to get to equal representation.
(Of course, this isn't a really accurate representation of the job market, as there are a large number of recent-ish graduates in post-doc jobs, so there's a larger reservoir of talent available right off. I don't know how to quantify that, though, and again: I'm just trying to get a sense of scale, here...)
And just for giggles, what would the "shitloads of money" option require? Well, a few years back I recall the administration saying that they needed a donation of about $2 million to endow a faculty line. That's a few years out of date, but then we pay a bit better than the median for faculty, and full professors in endowed chairs make more than new hires. So it's probably not completely ridiculous to use as a number for sense-of-scale purposes.
So, if you wanted to just make the gender-equity problem disappear overnight by creating a huge number of new faculty lines exclusively for women, you're talking about 5400 jobs at $2 million apiece, or just shy of eleven billion dollars. (Leaving aside the logistical question of who would fill all those jobs...)
So there's some back-of-the-envelope math for you. This was undertaken mostly to satisfy my morbid curiosity from yesterday, and has basically confirmed said curiosity as morbid. You could do something similar for astronomy departments, but I don't care enough to repeat it; you could also try to do a similar calculation for getting to proportional representation of racial diversity, but the numbers there are really depressing, so I'm not even going to look.
Again, the point here, as with all back-of-the-envelope calculations, is just to get a sense of scale. I'm not making a specific policy recommendation, or anything like that. Though if you do happen to have $11 billion burning a hole in your offshore bank account, drop me a line, and I'll be happy to make some suggestions...
in recent years there were about 1900 Ph.D.’s in physics awarded per year, and around 20% of those went to women
This statement tells me that the gender diversity problem is an issue long before anybody gets to the stage of looking for tenure track jobs. It's one thing to ask whether the diversity of the faculty is in line with the (suitably lagged) diversity of their students, and another thing to compare it to the general population, most of whom do not aspire to a tenure-track position in physics.
The basic question is whether the fraction of women among recently hired tenure-track faculty agrees within Poisson statistical errors with the fraction of women getting Ph.D.'s. IOW, are the chances of a woman (or minority) being hired as a tenure track professor significantly different from the chances of a male (or white) candidate? If not, then it's a pipeline issue, and focusing on faculty hires is not necessarily the right approach. If the woman (or minority) candidate already has significantly higher chances of being hired, then increasing that fraction is almost certainly the wrong approach. But if it is significantly lower, then yes, this is a separate problem from the pipeline issue.
The fraction of women hired into faculty jobs is consistently a few percentage points higher than the fraction of women getting Ph.D.'s over the previous few years. The report on women linked above says that women are 22% of all assistant professors in 2010, and 29% of newly hired assistant professors in 2010.
Re comment #1: For back of the envelope purposes, we can assume the pool of potential hires is much larger than the number of hires, so we can use the binomial. If 20% of the pool of potential hires are women, we would expect, for 7600 positions drawn randomly from the pool, 1520 women, with a standard deviation of sqrt(.2*.8*7600) = 34.87. If we have 1100 women, then there is a deficit of 420 women, or 420/34.87 = 12.04 standard deviations from the expected mean.
This maybe somewhat misleading, since the demographics of the faculties is a kind of average over the last 40 years or so, and so would reflect both the numbers of women in the pool and any bias against hiring women over that entire time frame, not just currently. In the previous comment it is suggested that the new hires are close to the expected numbers based upon the current pool of potential hires, but it will take 30-40 years of so for the total faculty numbers to catch up.
Based on the previous comment, if gender equality for the entire population (i.e., 50%) is the goal, rather than gender equality of the pool of potential hires (i.e., 20%), then the effort seems to be needed in attracting women into the field, rather than any current bias against them in hiring.
First, the AIP report about number of faculty struck me as rather out of touch. They wrote about the percentage of faculty in temporary positions in 2009-2010 as if the economy had been "uncertain" rather than in a nascent depression complete with 10% or more budget cuts! Worse, they seem to think that full-time instructors at a university are somehow more real than a tenured professor at a 2-year college that teaches exactly the same classes. They don't count that group at all, or look at who teaches physics in high school (if anyone).
Second, the marketplace for R1 faculty includes persons from overseas, so the pool can be enlarged from what you were looking at. Further, a masters is sufficient to teach at a BS-only college, which opens it up even further if your goal was to have a teaching faculty that was more diverse. Only MS and PhD departments need to have faculty with the terminal degree according to our accreditation standards, and you can have faculty at a university who don't have graduate status. Quite common in math at large universities.
Finally, the essential question is whether more role models will increase interest in the field and thus enlarge the hiring pool in the future. It certainly can't hurt, but my observation is that the pipeline problem is actually in high school. I haven't looked at it recently, but the percentage of women in a scientific field seems to track with the science they take first: biology, then chemistry, then physics. There is also a math issue. I see lots of women (and men) interested in engineering or physics who come in with a very weak background in algebra. That can only be fixed by radically repairing the K-8 math curriculum, which seems to be getting worse every year.
Maybe, as a general rule, female brains just aren’t cut out for, or drawn to, physics.
Fortunately, I can’t be fired for making such a blue sky/out-of the box proposition.
(Lawrence Summers wasn’t so lucky.)
A few years back, a few of us (led by a female physics PhD) devised a set of scientific workshop for teenagers. We worked really hard to make the workshops as cool and as interesting as possible. We handed questionnaires.
It was clear-cut: we really impressed the boys, who changes their attitude from a dislike of science to enthusiasm. The surprise was that we got the same change in reaction from the girls - only that was in the other direction. The girls hated it. They clearly went from a favorable attitude towards physics to aversion.
I'm still heart-broken.
Fortunately, I can’t be fired for making such a blue sky/out-of the box proposition.
Fortunately, you are not now, and have never had the capability to be, in a position to make decision about who is and is not qualified to be drawn to physics.
"Quite common in math at large universities."
Masters level faculty in math are not as common now as they were a few years ago, and are becoming more likely to be part-time than anything else, as "cost cutting" becomes more important than long-term quality.