Last week on Let’s Talk Development, I asked what the term “science of delivery” (SOD) means. I suggested that SOD is about moving from thinking about “what to deliver” to “how to deliver”. We know, for example, the interventions that cut child mortality (bednets, vaccinations, breastfeeding, etc.) but these interventions reach too few children, and the trick is to get them delivered to more. Much of the Bank’s analytic work, policy dialogue and lending work has focused precisely on how to reform policies and programs to ensure the interventions that are needed to improve development outcomes actually reach people. Much of this work merits the term “science” – it makes use of an explicit “theory of change” in the form of a results framework that reflects the latest social science, and builds on rigorous empirical evidence that compares actual outcomes with an explicit and plausible counterfactual.