The Game Theory of Getting a PhD
The Game Theory of Getting a PhD
How a system that works the opposite as it's supposed to actually kind of sort of achieves its goal.
The road to earning a PhD is arduous. First-year coursework. Preliminary exams. Comprehensive exams. Low pay. Long hours. Even non-academics are familiar with the grand finale: the dissertation. A dissertation, or thesis, is supposed to be a novel contribution to a student's field of study. A small but legitimate contribution to one's discipline. Graduate students spend years reading, researching, and writing to finish this one project. Depending on the field, a dissertation may be several articles suitable for journal publication or a book-length project on one topic. At the end of it all, however, comes the dreaded oral dissertation defense.
It's easy to imagine a pitiless oral defense. One lonely PhD student standing at the bottom of a steep lecture hall. Naked lightbulbs pointed directly at the quivering supplicant. Five shadowy figures in the back, thundering down questions as the student desperately tries to come up with reasonable answers. For hours the student is subjected to grueling interrogations that would make the Spanish Inquisition blush. At the end, the shadowing figures convene before a disembodied voice simply states, "DENIED." And the poor student is relegated to a lifetime of adjunct work.
Fortunately, that is not how dissertation defenses generally go. Instead, a student will discuss their research in front of a committee of 4-8 professors, possibly with other students in attendance. The committee members will provide some feedback, but the outcome of a dissertation defense is generally a formality. A student almost always passes their defense and is awarded their PhD (and unfortunately are often still relegated to a lifetime of adjunct work).
If the defense is a formality, does that mean there are no safeguards in place? No checks and balances to make sure a student is deserving of a PhD and a department isn't just a glorified diploma mill? On the contrary, there are several, mainly situated in the composition of a dissertation committee.
The key member of a dissertation committee is the student's doctoral advisor, a professor who has been working with the student for years guiding the dissertation. Then there are several other members of the committee who are professors in the same department; individuals who probably aren't intimately familiar with the student's work, but publish research similar to that of the student and can judge it accordingly. Then there is usually a professor in a different department in an adjacent discipline that can provide some meaningful feedback.
The key here is that each professor on the committee provides a hurdle that a student has to successfully negotiate. Even one professor who believes the dissertation isn't up to scratch can prevent or delay the conference of a degree. Thus, in theory, only students truly deserving of a diploma get through this rigorous and mutually supported system and are awarded their degrees.
It's all for show.
Classic game theory tells us why. Passing a dissertation defense is a one-shot game; each student only has to pass their dissertation once. But serving on dissertation committees is a repeat game; a professor will serve on the committee for their colleagues' students in the expectation that their colleagues will later serve on the committee for their students. This, of course, is where the checks and balances begin to break down. Sure a committee member could torpedo the dissertation defense of a rival professor's student; as the old saying goes, university politics are so vicious precisely because the stakes are so small.
But what goes around comes around. If a vengeful professor seeks retribution on a rival by failing one of the rival's students, eventually that rival can return the favor. Additionally, if a professor tries to hold up another professor's student, then no one will want the vengeful professor on their own students' dissertation committees.
This is even more true when considering the outside-the-department committee member. If an anthropology professor were to cause a ruckus during a history dissertation defense, there would be hell to pay. First, there would be a question of one anthropology professor knowing more about history than multiple history professors. Second, no department would want anyone from anthropology serving on their students' committees, and anthropology would have difficulty getting other professors to sit on their students' committees.
As brutal as university politics can be, in some areas you don't step on other people's toes. Professors are extremely hesitant to overrule their colleagues and try to prevent someone else's student from graduating. The system appears to have ostensible checks and balances, but does not.
Or are there? Because while the ostensible checks and balances do not function in the way they were intended, there is a shadow system in place that surprisingly works fairly well. Again, game theory and incentives explain why. While no professor wants to prevent a colleague's student from graduating, professors also care a great deal about their reputation. So nobody wants to be known as the professor that will let any student graduate, either.
Why would a professor care about passing lackluster students? It's all about prestige. When a committee tells a student they have passed their defense, they are inviting that student to join their "club", if you will. This club is regarded, at least by professors, as an important one. Being part of the PhD club confers lifetime membership and means your opinion on your subject carries more weight than most others. Ever notice how many book covers will have the letters "PhD" emblazoned on them as if that was the author's last name? Sometimes the "PhD" takes up more space than the title of the book!
Most professors only want membership conferred on those that have earned it, and they want their colleagues to know that they aren't a pushover. By serving on dissertation committees, they learn the bar that their own students need to clear. They only allow a student to defend their dissertation if that student has met the advisor's standards, and the department's standards, for club admission. If a student isn't ready, then an advisor won't allow them to defend.
So the system kind of, sort of, works. The checks and balances are there, but they work beneath the surface. At least in my personal experience, those that were deserving of PhDs got them. Those that were not deserving didn't. This system isn't perfect. There are certainly cruel advisors who hold their students to way too high of standard and prevent them from graduating. There are entire departments that serve as little more than PhD diploma mills. Overall, though, this shadow system of checks and balances has held up better than one would think.
Maybe the ultimate irony is that the key moment in a PhD student's dissertation process isn't at the defense, it isn't even during a class, but in their advisor's office. There comes a time when every PhD student walks their advisor through their progress and asks, "Can I defend my dissertation this spring?" If the answer is yes, then with little fanfare or attention that student has cleared the toughest bar in completing their dissertation. Congrats - now it just needs to be written.