While most 15-year-old students spend part of their after-school time doing homework, the amount of time they spend on it shrank between 2003 and 2012. Socio-economically advantaged students and students who attend socio-economically advantaged schools tend to spend more time doing homework....

Some 65% of socio-economically advantaged students reported that they know well or have often heard of the concept of quadratic function, on average across OECD countries; but only 43% of disadvantaged students so reported. On average across OECD countries, the 20% of students who are most...