Between 1990 and 2013, the share of students nationally who enrolled in algebra or a similar advanced math course in eighth grade more than doubled to 46 percent. Since 2013, however, the trend has reversed, with just 36 percent of eighth graders enrolled in algebra as of 2022. Successful completion of algebra or related math courses in grade eight can put students on track for calculus and more in high school. Some research finds that, without that early boost, subsequent mathematics achievement shrinks. Yet other studies find that broad policies to increase enrollment in early algebra lead to test score declines. Which is it? A recent working paper aims to resolve these conflicting findings.

The research team uses test-score, demographic, course enrollment, and other data from the Oregon Department of Education that include eighth grade students enrolled in any math course during 2014–15 to 2016–17. They had to have seventh grade test scores and attend schools with fifty or more eighth graders. Statewide, around 31 percent of eighth graders took algebra or advanced algebra. Since there isn’t a formal cutoff score on the test that determines whether eighth graders are enrolled in algebra, the researchers take a number of analytical steps to identify one. In a nutshell, they find various discontinuities in enrollment patterns by each school and run multiple simulations to identify those that represent true cutoff points in terms of algebra enrollment (which sets up the analysis for a regression discontinuity design). They end up with forty-nine schools that enroll roughly 5,500 kids, and control for the fact that schools have varied cutoffs. As intended, they show that placement rates into eighth grade algebra increase by more than 40 percentage points at the respective threshold.

Key results reveal significant increases in eighth grade math test scores of 0.12 standard deviations (SD), and smaller increases in eighth grade English language arts test scores of 0.06 SD for students who score above the cutoff. They also find a decrease in absences that equates to nearly one day. All positive.

Then they look into the extent to which teacher and peer exposure account for the impacts. They find that being placed into eighth grade algebra has a significant impact on the education level, experience, and value added of a student’s eighth-grade math teacher. For example, scoring above the threshold results in the value added of a students’ eighth-grade math teacher increasing by 0.09 standard deviations; moreover, such students are significantly more likely to be exposed to a math teacher in the top quartile of value added. However, the same pattern is not seen in ELA, so they conclude that, while teacher characteristics might account for the math test score effects, they are unlikely to account for ELA test score effects.

Moving on to peers, the results show effects on *peer* test scores in *both* ELA and math classrooms, such that eighth-grade algebra course enrollment reduces the number of math class peers who have experienced school suspensions and leads students to be exposed to higher-achieving peers in math classrooms. For example, among students scoring above the cutoff, analysts see large increases (0.55 SD) in the mean seventh-grade math score of a student’s eighth-grade math class. The differences in eighth-grade ELA classes are substantially less.

Because the math courses that students take can shape their course schedules more broadly, they also examine the mean achievement of classmates with which focal students share three or more classes. They find that students in eighth-grade algebra courses move through their school day with significantly higher-achieving peers—and that the magnitude of those peer effects is so large that it could account for the majority of eighth-grade algebra’s observed effects on student achievement.

The bottom line is that students who are prepared for eighth grade algebra or related advanced math courses gain immediate benefits from taking those courses, beyond math learning itself. But whether students are ready to take a higher math course is obviously a pivotal decision, and one for which schools have set varying thresholds. In addition, the mechanisms behind the success of the policy—high-quality teachers and high-achieving peers—are fixed commodities in any given school, at least until we approach staffing and acceleration differently. So simply expanding advanced algebra policies won’t do the trick. If only we had a magic wand.

SOURCE: Quentin Brummet et al., “Early Algebra Affects Peer Composition,” Annenberg Institute at Brown University (November 2023).