School composition and academic achievement: The case of Russian-medium and Polish-medium schools in Lithuania.

This article examines the academic performance of linguistic minority students in Lithuania, focusing on Russian- and Polish-medium schools compared to Lithuanian-medium schools, using 2018 data from the OECD's Program for International Student Assessment (PISA). It finds that minority-language students generally perform worse than Lithuanian-speaking peers, but those attending schools where the language of instruction matches their home language achieve better academic outcomes. The study highlights that socioeconomic status, school location (urban vs. rural), and gender also significantly affect student achievement. While separate minority-language schools mitigate some disadvantages faced by minority students, they do not fully close the achievement gap with Lithuanian-medium schools. The findings underscore the importance of mother-tongue instruction for minority students' academic success within Lithuania's linguistically separated education system.