A new working paper from the National Bureau of Economic Research shows that higher education in America is changing in more ways than one. Colleges and universities are increasingly hiring adjunct or part-time faculty instead of full-time professors, according to economists Liang Zhang, Ronald Ehrenberg, and Xiangmin Liu. Since 1993, the part-time share of faculty at four-year universities has risen from 30 percent to 38 percent, while full-time professors’ ranks have fallen from 60 percent to 51 percent.
Private institutions now employ part-time faculty and full-time professors in equal proportions. The less-flexible nature of public universities keeps full-time professors in the majority, but the trend is still clear. Adjuncts are rapidly becoming the new normal.
Hiring adjuncts makes financial sense for colleges. While full professors earn upwards of $75,000 per year, and often much more, part-time professors frequently earn less than $20,000. The pay gap, though large, does make sense, because part-time instructors are much less likely to hold an advanced degree. But why now? Why have colleges accelerated towards using adjuncts to meet their teaching needs over the past two decades?
Though the authors of the paper do not delve too deeply into potential reasons, the answer is likely booming student enrollment, driven by federal policy that subsidizes higher education. Over the 18-year study period, full-time equivalent student enrollment rose by 58 percent, compared to just 17 percent over the previous 18 years. All pistons are firing at American colleges.
As depicted on the chart, the increase in college enrollment coincides with the 1993-2011 study period. 1993 was also the year in which Congress created the Federal Direct Loan Program (FDLP), which gave government loans directly to students to help them pay for college. (The FDLP partially replaced a system of federal guarantees for private loans.) While the program was started with the best of intentions, researchers later found that the loans drove a substantial increase in college tuition as demand for degrees soared. But if the architects of the FDLP intended to get more students going to college, they succeeded.
An oversupply of college students, however, means that institutions will need additional teaching capacity. It follows that colleges would hire armies of part-time instructors to fill their classrooms. From an administrator’s perspective, low salaries and no obligation to provide tenure make adjunct professors the perfect solution to a large increase in enrollment.
The paper’s findings are consistent with this theory. A 10 percent increase in full-time equivalent students is associated with a 3.2 percent increase in part-time instructors, but only a 0.9 percent increase in associate and full professors. To meet demand, larger colleges populate their educators’ ranks with adjuncts.
A related reason for the increase in part-time instructors could be an explosion in course offerings, again driven by generous federal subsidies for higher education. According to a recent report published by the American Council of Trustees and Alumni and summarized on Economics21, many American colleges have adopted unnecessarily broad catalogs of classes. Extensive course offerings attract students (and the federal dollars that follow them), but also require additional professors. Colleges have enlisted adjuncts to fill the gap.
Other evidence is consistent with this theory. According to a survey conducted by the Coalition on the Academic Workforce, between 55 and 71 percent of adjuncts teach only one or two courses per semester, which signals the flexibility of their hiring arrangements. The survey also found that adjuncts earn a median of just $2,700 per course taught, making them a far more economical option than hiring new tenure-track professors to cover the course load.
Is this good news for students? While the evidence is mixed, the answer is probably no. Using adjuncts does boost enrollment in a particular field of study, suggesting that students like their part-time professors. But this enrollment boost is a curse in disguise.
Research by Scott Carrell and James West shows that students in classes taught by less-experienced faculty score better than their peers, but then perform much worse once they take additional classes in the field. Their findings suggest that adjuncts are eager to give students high grades and a low workload, since the instructors’ future at the institution is at least partially based on student reviews. This induces the students to take further courses in a field, courses which they may be unprepared for. Students may then choose the wrong path of study, and do worse overall in college.
This theory is consistent with the evidence surrounding the current crisis in higher education. Just 59 percent of students at four-year colleges graduate within six years, and 44 percent of those who do will not find a job that requires a college degree. The boost in part-time professors has not helped matters, and may have made things worse by drawing students into career paths for which they are not suited. It is perfectly possible that this phenomenon is at least partially responsible for the underdevelopment of American college students’ potential.
Finance of higher education in America requires serious reform, including more accountability measures for colleges and a tighter spigot of federal funds. While adjunct instructors might be happy that they have more job opportunities, their newly prominent role in our higher-education system may not be the best for students.
Preston Cooper is a policy analyst at the Manhattan Institute. You can follow him on Twitter here.
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