This Project aims to understand time investment decisions of children and adolescents. There is a need for more robust evidence on the combination of time investments that improve early cognitive skills and wellbeing. Using advanced econometric techniques and longitudinal data, this Project expects to generate new knowledge on how children and adolescents spend their time, and how such time investments affect their health and cognitive development. Expected outcomes of this Project include a greater understanding of the early determinants of health and economic inequalities. This is expected to benefit the development of effective policies for improving educational outcomes, preventing harmful behaviours and promoting health and wellbeing.