„The sociocultural average of the school population is the single most influential school characteristic in all Organization for Economic Cooperation and Development (OECD) countries, more important than either a shortage of qualified teachers or class size.“
Univ.-Prof. Dr. Jaap Dronkers u.a., „Positive but also Negative Effects of Ethnic Diversity in Schools on Educational Performance?“. In: Windzio (Hrsg.), „Integration and Inequality in Educational Intitutions“ (2013), S. 71