Yesterday the Yale Daily News ran an article on our CS department’s faculty shortage, which generated some discussion among CS colleagues. Yale’s CS faculty shortage is not really news: for example, another YDN article over a year ago made basically the same point, and that probably wasn’t the first.

Setting aside Yale in particular, however, it is interesting to notice some broader trends in CS department growth. So here are a couple charts I recently put together.

The first estimates the number of tenure-track faculty in each of the top 20 CS departments, ordered accoring to US News’s current rankings. Major caveat: this faculty size data is completely unofficial and approximate, based purely on the number of apparent ladder faculty members listed on the respective CS department web sites. Obvious potential sources of error include, for example, faculty positions that are split across departments but not clearly labeled as “adjunct” or “courtesy” appointments, and combined CS-and-EE departments in which it is not always obvious which faculty are more “CS” and which are more “EE”. But these represent best guesses based on publicly available information and are reasonably accurate to the best of my knowledge. The CRA folks who put together the Taulbee Survey probably have better and more “official” data, but I don’t have that data.

As the orange line indicates across the left half of the chart indicates, CS departments in the top 10 appear to average about 67 ladder faculty, with Carnegie Mellon, MIT, and Georgia Tech being by far the largest, and Princeton being the smallest of the top-10 at around 35 faculty. As the yellow line on the right side indicates, departments in the “next 10” category appear to average around 39 ladder faculty each.

None of this is likely to be much of a surprise to anyone familiar with CS academia. What is more interesting is to look at the relative faculty growth over the past decade, broken down the same way below. The baseline numbers are derived from the corresponding CS department home pages as captured by the Internet Archive around September 2004.

The average growth of the CS departments currently in the top 10 is a relatively modest 8% since 2004. My sense is that most if not all of these top-10 departments have been hiring aggressively and more-or-less continuously over the past decade, but mainly just filling the vacancies regularly created as faculty get sucked away to industry positions or startups. But these departments haven’t needed to grow “much” because, hey, they’re already on top of the heap.

But the picture for the “next 10” category looks interestingly different, in which faculty size growth over the past decade appears to have been around 21% on average. Unless I’m mistaken, USC in particular has nearly doubled in size over this period, and a majority of departments in this category grew at least 20%. Might we say these are the departments “bucking for the top 10”?

This is all just for what it’s worth; no warranties yadda yadda. Comments or corrections of any inaccuracies are welcome.