On the wrong track
College students share a table and study together at the Erb Memorial Union building on the University of Oregon campus.
Joshua Rainey Photography
Many parents, teachers, and schools push to sort students by academic achievement — a policy known as “tracking.” For example, thirty-five of the fifty flagship state universities in the US offer residences restricted to honors students.
But universities that use residential tracking may be doing so at the expense of lower-achieving students for very little benefit to higher-achieving students, according to a paper in the July issue of the American Economic Journal: Applied Economics.
Robert Garlick of Duke University studied the impact of a change in the University of Cape Town’s (UCT) dormitory assignment policy. Before 2006, UCT tracked incoming students into dormitories based on high school test score. From 2006 onward, UCT randomly assigned incoming students to dormitories.
Garlick found no statistically significant impact on the college GPAs of higher-achieving students from tracking. Meanwhile, lower-achieving students performed worse when tracked. Garlick argues that this result can be attributed to “peer effects,” which arise when one’s peers affect one’s education, for example, through study habits or disruptive dormitory behavior.
Figure 3 from Garlick (2018)
Tracking at UCT effectively sorted students by high school performance — demonstrated by the blue line in figure 3 from his paper, shown above. The higher a students’ high school test scores are, the higher their dormmates’ high school test scores are.
Then peer effects adversely impacted students who entered with lower high school test scores — demonstrated by the red line. Students with scores in the bottom quartile would have seen their GPA reduced by roughly 0.2 standard deviations if they had been tracked. Whereas students in the top quartile might have seen a slight gain in their GPA.
How students are grouped offers an important tool for education policymakers. It may be attractive to education policymakers because it’s cheap to implement, but could significantly affect the distribution of educational outcomes.