The achievement gap between students from different socioeconomic backgrounds is one of the most persistent challenges in education systems worldwide. While significant attention has been given to between-school segregation, less is known about how sorting practices within schools contribute to widening inequalities. In their recent study, Zoltán Hermann and colleagues, Hedvig Horváth and Dorottya Kisfalusi investigate this very issue, focusing on the Hungarian education system. The study explores whether within-school sorting—separating students into different classrooms based on socioeconomic status—exacerbates existing achievement gaps.
The findings are striking: sorting students within the same school can significantly widen the achievement gap between high- and low-status students. The implications are far-reaching, highlighting the need for policy interventions that address not only the allocation of resources between schools but also the distribution of students and educational opportunities within them.
The Problem of Sorting Within Schools
The idea of sorting students within schools is not new. In many education systems, students are grouped based on perceived ability, prior achievement, or even parental influence. This can result in a concentration of higher socioeconomic status (SES) students in certain classrooms, where they receive more attention, better resources, and stronger peer support. Meanwhile, students from lower SES backgrounds are often grouped together, resulting in classrooms with fewer resources, lower expectations, and less academic support.
In Hungary, sorting based on ability is legally restricted until after the 8th grade, making the country an ideal setting to study the effects of non-merit-based sorting on educational inequality. The study by Hermann and colleagues focuses on primary schools, where classrooms are formed in the first grade and typically remain the same until students finish the 8th grade. Despite the absence of formal tracking, informal sorting based on socioeconomic status is common, driven by factors such as parental preferences, teacher selection, and school policies.
Methodology: Measuring the Impact of Sorting
The study uses a rich dataset from the National Assessment of Basic Competencies (NABC) in Hungary, which includes test scores and socioeconomic information for students in the 6th and 8th grades. By examining nine cohorts of students, the researchers were able to measure the extent of sorting in each school and its impact on test score inequalities.
The researchers classified schools into two groups: “sorting schools,” where students are systematically assigned to different classrooms based on socioeconomic status, and “non-sorting schools,” where students are randomly assigned. To identify sorting schools, the authors used a data-driven approach, testing whether classroom assignments were significantly related to students’ SES.
After repeating this excersice for each school year, they compared the test score gaps between high- and low-status students in a sorting and non-sorting setup within the same school, controlling for factors such as overall student composition, and prior achievement.
Key Findings: Sorting Worsens Inequality
The results reveal that within-school sorting has a significant and negative impact on low-status students, while high-status students benefit only marginally from being in sorting schools. The socioeconomic test score gap was 11–38% larger in math and 7–23% larger in reading in sorting schools compared to non-sorting ones. In other words, students from disadvantaged backgrounds fared significantly worse in schools that sorted students into classrooms based on SES.
Interestingly, while high-status students did experience some benefits from sorting, these gains appear smaller than the losses experienced by their low-status peers. This suggests that the primary effect of sorting is not to boost overall academic achievement but to widen the gap between advantaged and disadvantaged students.
Mechanisms Behind the Sorting Effect
Although available data limits the authors ability to fully explore the mechanisms, they do speculate and provide suggestive evidence about what factors may account for the widening achievement gap. First, peer effects play a crucial role: high-status students benefit from being surrounded by other high-achieving peers, while low-status students in sorting schools are more likely to be grouped with lower-performing classmates, which negatively impacts their own academic performance.
Second, resource allocation within schools is another key factor. Relying on a related study, the authors find that in sorting schools, higher-status classrooms tend to receive more qualified teachers.
Finally, differences in educational practices, such as homework assignments and classroom expectations, may also contribute to the sorting effect. The authors provide survey evidence that high-status students in sorting schools are more likely to receive challenging coursework and extra academic support, while low-status students are often left behind with less rigorous assignments and fewer learning opportunities.
Implications for Policy and Practice
The findings of this study have important implications for education policy, particularly in countries like Hungary, where within-school sorting is widespread but not formally acknowledged. To address the widening achievement gap, policymakers need to focus not only on reducing between-school inequalities but also on creating more equitable learning environments within schools.
One potential solution could be to implement stricter regulations that prevent schools from informally sorting students based on socioeconomic status. However, the evidence suggests that legislative tools are ineffective in eliminating sorting as schools find a way to evade the rules by grouping students into different classes through informal processes.
Therefore, in addition to setting legal barriers to sorting, policy makers may also want to shape schools’ economic incentives. Properly designed school accountability measures may alter the incentives to sort and assign less or inferior resources to low-status students. For instance, in the US schools are required to report educational progress metrics not only for all students together but also separately for different socioeconomic subgroups.
Conclusion
Zoltán Hermann and colleagues’ study highlights the significant role that within-school sorting plays in exacerbating the socioeconomic achievement gap. While the practice of sorting students may offer some benefits for high-status students, its primary effect is to deepen existing inequalities, leaving low-status students further behind. As education systems strive to create more inclusive and equitable environments, addressing the issue of within-school sorting must be a priority. By doing so, we can ensure that all students, regardless of their background, have the opportunity to succeed.
This blog post is based on the research paper: “Are separate classrooms inherently unequal? The effect of within-school sorting on the socioeconomic test score gap in Hungary,” published in Economics of Education Review.
