for example pisa shows that in nearly all countries and economies students who had attended preprimary school tend to perform better at the age of than students who had not attended even after accounting for students socioeconomic status fifteenyearold students in were more likely than yearolds in to have attended at least one year of preprimary education but the rate of increase in preprimary enrolment is higher among advantaged students than disadvantaged students which means that the socioeconomic gap between students who had attended preprimary education and those who had not has widened over time