TITLE: Why Do CS Enrollments Surges End?
AUTHOR: Eugene Wallingford
DATE: October 03, 2017 12:23 PM
The opening talk of the CS Education Summit this week considered
the challenges facing CS education
in a time of surging enrollments and continued concerns about
the diversity of the CS student population. In the session that
followed, Eric Roberts and Jodi Tims presented data that puts the
current enrollment surge into perspective, in advance of a report
from the National Academy of Science.
In terms of immediate takeaway, Eric Roberts's comments were gold.
Eric opened with
If something is unsustainable, it will stop. Stein was an economist
whose eponymous law expresses one of those obvious truths we all
seem to forget about in periods of rapid change: If something
cannot go on forever, it won't. You don't have to create a program
to make it stop. A natural corollary is: If it can't go on for long,
you don't need a program to deal with it. It will pass soon.
Why is that relevant to the summit? Even without continued growth,
current enrollments in CS majors is unsustainable for many schools.
If the past is any guide, we know that many schools will deal with
unsustainable growth by limiting the number of students who start
or remain in their major.
Roberts has studied the history of CS boom-and-bust cycles over the
last thirty years, and he's identified a few common patterns:
So the challenge of booming enrollments exacerbates the challenge
to increase diversity. The boom might decrease diversity, but
when it ends -- and it will, if we limit enrollments -- our
diversity rarely recovers. That's the story of the last three
In order to grow capacity, the most immediate solution is to hire
more professors. I hope to write more about that soon, but for
now I'll mention only that the problem of hiring enough faculty
to teach all of our students has at east two facets. The first is
that many schools simply don't have the money to hire more faculty
right now. The second is that there aren't enough CS PhDs to go
around. Roberts reported that, of last year's PhD grads, 83% took
positions at R1 schools. That leaves 17% for the rest of us.
"Non-R1 schools can expect to hire a CS PhD every 27 years."
Everyone laughed, but I could see anxiety on more than a few faces.
The value of knowing this history is that, when we go to our deans
and provosts, we can do more than argue for more resources. We can
show the effect of not providing the resources needed to
teach all the students coming our way. We won't just be putting
the brakes on local growth; we may be helping to create the next
enrollment crash. At a school like mine, if we teach the people of
our state that we can't handle their CS students, then the people
of our state will send their students elsewhere.
The problem for any one university, of course, is that it can act
only based on its own resources and under local constraints. My
dean and provost might care a lot about the global issues of demand
for CS grads and need for greater diversity among CS students. But
their job is to address local issues with their own (small) pool
I'll have to re-read the papers Roberts has written about this topic.
His remarks certainly gave us plenty to think about, and he was as
engaging as ever.
- Limiting enrollments is how departments respond to enrollment
growth. They must: the big schools can't hire faculty fast
enough, and most small schools can't hire new faculty at all.
- The number of students graduating with CS degrees drops because
we limit enrollments. Students do not stop enrolling
because the number of job opportunities goes down or any other
After the dot-com bust, there was a lot of talk about offshoring
and automation, but the effects of that were short-term and
rather small. Roberts's data shows that enrollment crashes do
not follow crashes in job openings; they follow enrollment caps.
Enrollments remain strong wherever they are not strictly
- When we limit enrollments, the effect is bigger on women
and members of underserved communities. These students
are more likely to suffer from impostor syndrome, stereotype
bias, and other fears, and the increased competitiveness among
students for fewer openings combines with discourages them from