Ethnic Diversity, Immigrant Concentration, and Immigrant–Native Gaps in Academic Performance

Background

Educational inequalities between native students and those with an immigrant background remain a persistent challenge in many European societies. While a large body of research documents achievement gaps between immigrant-origin and native students, less is known about how these gaps vary across school contexts with different levels of immigrant concentration and ethnic diversity.

Objective

This study examines whether immigrant–native gaps in educational attainment vary by school ethnic composition, focusing on both the proportion of immigrant students and the level of ethnic diversity within schools. Specifically, it investigates differences in academic performance among native students, 1.5-generation students, and second-generation students, and assesses how these differences are moderated by school-level immigrant concentration and diversity.

Method

The analysis uses administrative registry data from Catalonia, Spain, covering standardized test scores of students in the sixth grade of lower-secondary education. The dependent variables are achievement scores in reading, mathematics, and science. The key independent variable captures students’ migration background, distinguishing between native students, 1.5-generation students (foreign-born students who arrived during childhood), and second-generation students (native-born children of immigrants). To account for the hierarchical structure of the data, multilevel models are estimated with students nested within schools. At the school level, two moderators are included: the proportion of immigrant students and ethnic diversity, measured using Herfindahl’s diversity index.

Results

The findings reveal that higher proportions of immigrant students are associated with lower average achievement and with widening immigrant–native gaps, particularly in reading and science. In contrast, higher ethnic diversity is associated with higher average performance in reading and science, but not in mathematics. However, interaction effects show that the benefits of diversity are unevenly distributed: second-generation students benefit significantly less from ethnically diverse school environments than native students, resulting in persistent or even widened achievement gaps. Mathematics outcomes appear comparatively insensitive to both immigrant concentration and ethnic diversity.

Conclusions

These findings demonstrate that immigrant concentration and ethnic diversity operate through distinct mechanisms and have different implications for educational inequality. While diversity is associated with higher average performance, it does not uniformly reduce immigrant–native achievement gaps. The results underscore the importance of distinguishing between different dimensions of school composition and between immigrant generations when evaluating school effects.