„On average across the OECD countries, the performance difference associated with a one-unit increase in the PISA ESCS index is equivalent to more than one year of schooling. The biggest impact of all is found in France, where a one-unit increase in the ESCS index is associated with an average improvement across the three subjects of 56 score points, the equivalent of almost two years’ schooling.“
UNICEF (Hrsg.), „Building the Future. Children and the Sustainable Development Goals in Rich Countries“ (2017), S. 41
Anmerkung: In Österreich sind es 44 Punkte, in Finnland und Deutschland 39 Punkte.