International differences in childhood socio-economic inequality are already apparent by the time children begin school …

„International differences in childhood socio-economic inequality are already apparent by the time children begin school and remain largely, although not perfectly, stable over time.“
Dr. Jascha Dräger u. a., Cross-national differences in socioeconomic achievement inequality in early primary school: the role of parental education and income in six countries (2023), S. 8.