Memoirs of Dickey-Fuller

This past reading period, I was slightly surprised to find that the material that was the most challenging was the easiest to study. My econometrics exam came and went with the rest of finals, but the memories of studying will keep me smiling long into this second semester.

Because data could be either stochastically trending, serially correlated or both, and because the terms sounded just similar enough to be potentially confusing, I took solace in my study group. My two compatriots helped improve my understanding of the material and made me laugh. Some of the most valuable resources that Harvard offers its students are one another. Economists like Gordon C. Winston at Williams College have written about peer effects in higher education. These economists like to compare colleges to firms, with students as consumers of an education. But unlike most firms, students are also the inputs that create the education we all consume. While your New Balance running shoes are not more comfortable, durable or attractive because your roommate also bought a pair, your education is inherently more valuable because the same roommate aces his math quizzes, Italian compositions or response papers—whatever the case may be.

This peer effect theory is often used to explain the existence of large merit scholarships and why Harvard is willing to spend so much more per student than we pay in tuition. Every undergraduate is worth something to the students around him. The free rides that some highly-qualified students get at state schools is a signifier of their value to their peers. National merit scholars’ tuition is waived at some schools because they raise the value of the education that paying students receive. If the difference between per-student spending and tuition is a measure of peer effects, at Harvard—where this measure is over $40,000, according to U.S. News and World Report—our peers are worth a bundle.

If we haven’t fully taken advantage of our fellow students by winter break, the end of the semester is the time to get our money’s worth—and many of us do. We form “study groups” by assigning members of the class different portions of the semester’s reading to summarize. But these are “study groups” by name only.

While there’s nothing wrong with trading a short summary for a mini version of the sourcebook, it does little to further our understanding of the material or to question the positions we have taken. When we’re looking for “just the facts, ma’am,” we’re often disappointed when students in our core class have decided to document their own interpretations of Going After Cacciato, instead of just telling us what happens in the story so we can potentially use it as an example on the final. In these cases, we’re hardly using the resources of our peers. If the entire syllabus were on Sparknotes.com, we’d be even happier.

Study groups have the potential to be more than just sieves for the reading we didn’t do. When students get together to discuss the subject matter and ask one another questions, they can more effectively prepare for an exam.

Receiving substantial help from fellow students is part of getting the most out of college. And providing help to one’s peers is an educational tool that is often ignored. Conventional knowledge teaches that you only really understand material when you can explain it to someone else. Students who do the majority of the explaining can benefit just as much from a study group as those who mostly listen.

Size is also a concern in organizing an effective study group. More participants can potentially bring new insights into a discussion, but a larger group is also more likely to turn into a purely social event. For example, if each individual in a study group is expected to pay attention 90 percent of the time—or nine minutes out of every ten—a group of five will simultaneously focus just 60 percent of the time. The ideal size, then, is a small study group of three or four people, which allows for varying perspectives but is less likely to stumble into constant distraction.

But study groups are about more than helping everyone boost their grades. They’re about helping everyone boost their grades in “style.” For me, a more complete understanding of econometrics came from a discussion with my compatriots about the Dickey-Fuller test, which is ideal when checking for the aforementioned stochastically trending data—unless you’re also afraid of serially correlated data, in which case the augmented Dickey-Fuller test is preferred.

We knew Dickey and Fuller were two very famous econometricians, but that didn’t stop us from giggling at the name of the test or daring one another to write “in loving memory of Richard E. Fuller” on our exams.

In the long hours of study, laughter sends endorphins to your brain, allowing you to fight through the stress of study and plug on a little longer. Rarely will you fall into laughing spurts alone at your desk. But with a study group, in the few relaxed minutes you get to spend each hour, you have someone to ask whether or not your Dickey-Fuller should be augmented.

And with a study group, someone is likely to know.

Judd B. Kessler ’04 is an economics concentrator in Adams House. His column appears on alternate Tuesdays.