Book excerpt: POPULATION HEALTH SCIENCE formalizes an emerging discipline at the crossroads of social and medical sciences, demography, and economics--an emerging approach to population studies that represents a seismic shift in how traditional health sciences measure and observe health events. Bringing together theories and methods from diverse fields, this text provides grounding in the factors that shape population health. The overall approach is one of consequentialist science: designing creative studies that identify causal factors in health with multidisciplinary rigor. Distilled into nine foundational principles, this book guides readers through population science studies that strategically incorporate: · macrosocial factors · multilevel, lifecourse, and systems theories · prevention science fundamentals · return on investment · equity and efficiency Harnessing the power of scientific inquiry and codifying the knowledge base for a burgeoning field, POPULATION HEALTH SCIENCE arms readers with tools to shift the curve of population health.