It is well established that boys perceive themselves to be better in mathematics than girls, even when their ability is the same. We examine the drivers of this male overconfidence in self-assessed mathematics ability using a longitudinal study of twins. This allows us to control for family...

International large-scale assessments such as PISA are increasingly being used to benchmark the academic performance of young people across the world. Yet many of the technicalities underpinning these datasets are misunderstood by applied researchers, who sometimes fail to take their complex...