Shanghai is one of the most equal education systems among the PISA participants …

„Shanghai is one of the most equal education systems among the PISA participants. For example, it has the highest proportion of resilient students (19.2 percent), that is, disadvantaged students who perform among the top 25 percent of students across all participating countries and economies after controlling for socioeconomic status.“
Weltbank (Hrsg.), „How Shanghai Does It“ (2016), S. 102