Evidence-based policy making requires a holistic approach—from original research to actual implementation at scale—and we view a proper understanding of the science of using science as key to its success. In this chapter, we present an economic model that can help generate that understanding. The model, or framework, represents an intuitive way of categorizing threats to scalability that have been identified by the literature from diverse fields. We elaborate on the four major categories of scaling threats that emerge from the model and we provide a roadmap to help policy makers and practitioners understand and attenuate such threats. In doing so, we provide a scientific recipe for scaling that has implications and sets out expectations for policy makers, implementers, researchers, and funders.