Classroom Grade Composition and Pupil Achievement
利用挪威初中年级混合规则，研究发现混合年级班级的学生成绩优于单一年级班级，受益于与高年级同学同班，但低年级同学的存在有负面影响。
This article exploits discontinuous grade mixing rules in Norwegian junior high schools to estimate how classroom grade composition affects pupil achievement. Pupils in mixed grade classrooms are found to outperform pupils in single grade classrooms. This finding is driven by pupils benefiting from sharing the classroom with more mature peers from higher grades. The presence of lower grade peers is detrimental for achievement. Pupils can, therefore, benefit from de‐tracking by grade but the effects depend crucially on how the classroom is balanced in terms of lower and higher grades. These results reconcile the contradictory findings in the literature.