Earlier this month, a team of researchers at Northwestern University, including its president, Morton Schapiro, released a paper titled, "Are Tenured Professors Better Teachers?" Their answer, based on eight years of the school's student records, was essentially no. On average, tenure-line profs actually underperformed compared to their tenure-ineligible colleagues, at least when it came to the task of teaching first-term freshmen.
I'm not writing about this paper for a second time now because I particularly love my alma mater. Rather, this isolated, interesting study on a very specific university — with results that might not be generalizable beyond a handful of similar institutions — has managed to cause a great deal of controversy in academic circles, where some have interpreted it as a politically motivated attack on the entire concept of tenure.
Frankly, I deserve some of the blame for that. I slapped a broad, somewhat provocative headline on my own post about the study, then saved the careful qualifications for the story itself. But there was a much deeper cause behind the uproar. Tenure is slowly disintegrating, and that issue is very raw within higher education, more so than those outside the professoriate usually appreciate. Over the years, colleges of all stripes have chosen to save on their instruction costs by replacing full-time, tenured faculty with adjunct professors, who work on contract, often for breathtakingly low wages and no benefits. We're talking about Ph.D.'s who have to survive on food-stamps, in some exceptional but illustrative cases. Any study which might appear, even on a surface level, to validate that evolution from a teaching standpoint was sure to provoke some anxiety. As adjunct and writer Rebecca Schuman put it:
I fear that the result of this study will be trumpeted around universities with much less revenue and much lower adjunct pay than Northwestern, to justify the idea that, as Pannapacker has put it, since children make the best chimney sweeps, we should keep sticking children up chimneys.
“Since professors who work around rat infestations and hold office hours out of their cars make the ‘best’ teachers, we should kill that pesky tenure line and replace it, not with a humane multi-year, infinitely-renewable full-time contract position, but with four adjuncts whose combined wages equal that of a high-school teacher ten years their junior. And they can hold office hours from their 1996 Subarus, while what once were faculty offices get commandeered by a new fundraising office, tasked to support a new UltraDorm/strip mall with Jacuzzi tubs on every floor.” Don’t worry, they actually teach BETTER under those conditions! They like them!
So let's be clear today: Nothing about the Northwestern study suggests that colleges should embrace the rat-hole model of labor management. Rather, it's another piece of a growing economics literature that, taken as a whole, suggests exactly the opposite: Poorly paid, part-time faculty are poor substitutes for full-time professors.
What the Northwestern Study Says (and Doesn't Say)
What precisely did the Northwestern study show? In short, it found that the university's non-tenured faculty were better both at inspiring students to study a subject and at preparing them to do it. Freshmen were more likely to take an advanced course in a field, and generally earned higher grades in it, if a professor who was not tenured or on the tenure track taught their introductory class. The differences weren't enormous, but they were noticeable and consistent across different academic departments. On average, students were 7 percentage points more likely to take an advanced course in a discipline after starting off with a non-tenured prof, and earned around 0.06 to .12 grade points better in their second class (on a four point scale).
But here's the key bit, the absolutely essential context. The study did not show that adjuncts in particular make better teachers than tenured faculty. In fact, contrary to some of the headlines it generated, the study wasn't really about adjuncts at all.* Northwestern employs a large number of full-time, non-tenure track lecturers who, while they aren't necessarily compensated like star research profs, aren't subsisting on ramen and Mountain Dew wages either. Take Mark Witte, who has been teaching economics to Northwestern undergrads for about 25 years. Students consider him a campus superstar. And as USA Today noted, he doesn't have tenure. According to the Department of Education, the school's full-time lecturers like Witte make about $62,000 a year, on average (I'm guessing he makes much more, given the time he's been around and since he has the words "senior" and "distinguished" in his title).
Northwestern economist David Figlio, one of the study's co-authors, told me that at least 82 percent of the credit hours taught by non-tenured faculty were handled by lecturers like Witte.** And he noted that 99.4 percent of all non-tenure-track professors the study examined had worked with the school for at least six quarters. In other words, it was looking at experienced teachers who enjoyed longstanding relationships with the university. And if the self-reported data in the Chronicle of Higher Education's "Adjunct Project" are any indicator, Northwestern part-time profs are paid far better than your typical adjunct.
To review, what does the study tell us? If colleges pay their professors a middle-class wage to teach year-in and year-out, they might just do a better job of it than faculty who focus on research and publishing.
What the Other Studies Say
Now time for the big picture. The Northwestern study is just one paper, part of a small-but-growing volume of economics research into which kinds of professors make the best teachers. And collectively, they suggest that schools may be hurting students by over-relying on adjuncts, especially at the community college level, where part-timers are most prevalent.
In a 2005 article published in the Journal of Human Resources, Ronald Ehrenberg and Liang Zhang looked at data from almost 5,000 colleges and universities, and ultimately concluded that schools with fewer tenure-track faculty have lower graduation rates. Unfortunately, cause and effect were a bit murky. The study only looked at schools as a whole, rather than individual students, so it was difficult to tell whether they were dropping out because they were taking classes from adjuncts and lecturers, or if colleges with fewer tenured faculty were dealing with other internal problems that drove down graduation rates. Nonetheless, it suggested that a high ratio of non-tenure track professors wasn't exactly a sign of institutional health.
In 2006, however, Eric Bettinger and Bridget Terry Long published a book chapter that did address the graduation rate question by looking at student data. Analyzing the records of 43,000 undergraduates at public, four-year colleges in Ohio, they reached the "straightforward and unambiguous" result that freshman taught by adjuncts were more likely to drop out. In their words:
In the first semester of students’ academic careers, it matters what types of professors they meet on campus. If they take large proportions of classes from adjuncts and graduate students (after controlling for selection bias), they are more likely to drop out of the institution. This likely validates claims that adjuncts are ill-prepared to help integrate new students into a specific college.
Of note here: The big divide wasn't between tenured and non-tenured professors, but part-time vs. full-time.
Four years later, Bettinger and Long published a second study that added some interesting nuances to their findings. Ohio freshmen, they found, were actually more likely to take additional classes in a career-oriented field (think business, journalism, or computer science) if their first course was taught by an adjunct. In more academic departments (think English or History) students taught by adjuncts were less likely to come back for more. Once they looked beyond freshmen year, the authors found that adjuncts had a positive effect on student interest in every field, though it was still strongest in pre-professional areas of study.