Recorded at the CEPR Paris Symposium. Everywhere in the world there is still a stigma around periods. That can lead to bullying or exclusion in schools. Girls are stressed, and that affects their ability to study. In Madagascar, an RCT set out to end the stigma by discussing menstruation openly and seeking out Young Girl Leaders who could help their peers understand what was happening, and why it shouldn’t be a source of embarrassment or shame. Karen Macours of the Paris School of Economics tells Tim Phillips about the extraordinary effect of the programme on mental health and graduation rates.