„Comparisons of the PISA reading scores of 15-year-old students with immigrant parents and similar socio-economic backgrounds show that those who attended ECEC consistently achieve higher scores. Overall, across the EU, the benefit of having attended preschool is 55 points at the age of 15 among the native-born children of immigrants – roughly equivalent to 1.5 school years. The corresponding benefit among native-born children of native-born is 23 points, about half a year of schooling.“
OECD (Hrsg.), Young People with Migrant Parents (2021), S. 14.