CoolData blog

3 October 2016

Grad class size: predictive of giving, but a reality check, too


The idea came up in a conversation recently: Certain decades, it seems, produced graduates that have reduced levels of alumni engagement and lower participation rates in the Annual Fund. Can we hope they will start giving when they get older, like alumni who have gone before? Or is this depressed engagement a product of their student experience — a more or less permanent condition that will keep them from ever volunteering or giving?


The answer is not perfectly clear, but what I have found with a bit of analysis can only add to the concern we all have about the end of “business as usual.”


For almost all universities, enrolments have risen dramatically over the decades since the end of the second World War. As undergraduate class sizes ballooned, metrics such as the student-professor ratio emerged as important indicators of quality of education. It occurred to me to calculate the size of each grad-year cohort and include it as a variable in predictive models. For a student who graduated in 1930, that figure could be 500. For someone who graduated in 1995, it might be 3,000. (If you do this, remember not to exclude now-deceased alumni in your count.) A rough generalization about the conditions under which a person received their degree, to be sure, but it was easy to query the database for this, and easy to test.


I pulled lifetime giving for 130,000 living alumni and log-transformed it before checking for a correlation with the size of graduating class. (The transformation being log of “lifetime giving plus 1.”) It turned out that lifetime giving has a strong inverse correlation with the size of an alum’s grad class, for that alum’s most recent degree. (r = -0.338)


This is not surprising. The larger the graduating class, the younger the alum. Nothing is as strongly correlated with lifetime giving as age, therefore much of the effect I was seeing was probably due to age. (The Pearson correlation of LTG and age was 0.395.)


Indeed, in a multiple linear regression of age on lifetime giving (log-transformed), adding “grad-class size” as a predictor variable does not improve model fit. The two predictors are not independent of each other: For age and grad-class size, r = -0.828!


I wasn’t ready to give up on the idea, though. I considered my own graduation from university, and all the convocations I had attended in the past as an Advancement employee or a family member of a graduate. The room (or arena, as the case may be) was full of grads from a whole host of degree programs, most of whom had never met each other or attended any class in common. Enrolment growth has been far from even across faculties (or colleges or schools); the student experience in terms of class size and one-on-one access to professors probably differs greatly from program to program. At most universities, Arts or Science faculties have exploded in size, while Medicine or Law have probably not.


With that in mind, I calculated grad-class size differently, counting the size of each alum’s graduating cohort at the faculty (college) level. The correlation of this more granular count of grads with lifetime giving was not as negative (r = -0.283), but at the same time, it was less tied to age.


This time, when I created a regression of age on lifetime giving and then added grad-class size at the faculty level, both predictors were significant. Grad class size gave a good boost to adjusted R squared.


I seemed to be on to something, so I pushed it farther. Knowing that an undergrad’s experience is very different from that of a graduate student, I added “Number of Degrees” as a variable after age, and before grad-class size. All three predictors were significant and all led to improvements in model fit.


Still on the trail of how class size might affect student experience, and alumni affinity and giving thereafter, I got more specific in my query, counting the number of graduates in each alum’s year of graduation and degree program. This variable was even less conflated with age, but despite that, it failed to provide any additional explanation for the variation in lifetime giving. There may be other forms of counts that are more predictive, but the best I found was size of grad class at the faculty/college level.


If I were asked to speculate about the underlying cause, the narrative I’d come up with is that enrolments grew dramatically not only because there were more young people, but because universities in North America were attracting students who increasingly felt that a university degree was a rite of passage required for success in the job market. The relationship of student to university was changing, from that of a close-knit club of scholars, many of whom felt immensely grateful for the opportunity, to a much larger, less cohesive population with a more transactional view of their relationship with alma mater.


That attitude (“I paid x dollars for my piece of paper and so our business here is done”), and not so much the increasing numbers of students they shared the lecture halls with, could account for drops in philanthropic support. What that means for Annual Fund is that we can’t bank on the likelihood that a majority of alumni will become nostalgic when they reach the magic age of 50 or 60 and open their wallets as a consequence. Everything’s different now.


I don’t imagine this is news to anyone who’s been paying attention. But it’s interesting to see how this reality is reflected in the data. And it’s in the data that we will be able to find the alumni for whom university was not just a transaction. Our task today is not just to identify that valuable minority, but to understand them, communicate with them intelligently, connect with their interests and passions, and engage them in meaningful interactions with the institution.



Blog at

%d bloggers like this: