Direct and indirect effects of public policies and interventions

This dissertation evaluates the direct and certain indirect effects of the Active Living Program (a field experiment that stimulates children to become more physically active in their everyday lives), and opt-out consent for organ donation (a system in which you automatically become organ donor upon death unless you indicated otherwise). Both policies achieve most of their direct effects: the Active Living Program increases the amount of time children spend on physical activity during school-time, and opt-out consent for organ donation is related to significantly more transplants from deceased donors. However, both policies also appear to have undesirable indirect effects. The Active Living Program unintentionally worsens school performance, especially among the lowest-performing students and among boys, and it increases ADHD-like symptoms in boys. The thesis also shows that for kidneys and livers—by far the most commonly transplanted organs—the higher deceased-donor transplantation rates in opt-out systems give a false impression that presumed consent is related to lower organ-patient mortality rates.