To sort pupils at the end of primary school, some early-tracking systems apply a mechanism that unwittingly divides classes into two groups: students preparing for exams to enter better schools and everyone else, who decide not to compete for selective schools. Utilizing TIMSS data and a follow-up study in the Czech Republic, we show that this…

A large body of research has demonstrated a big-fish--little-pond effect (BFLPE) by showing that equally able students have lower academic self-concepts in high-ability schools than in low-ability schools. Although the BFLPE generalizes across many countries, it varies significantly between countries. The reasons for this variation are still…