Why are some societies more successful than others at promoting individual and collective well-being? This book integrates recent research in social epidemiology with broader perspectives in social science to explore why some societies are more successful than others at securing population health. It explores the social roots of health inequalities, arguing that inequalities in health are based not only on economic inequalities, but on the structure of social relations. It develops sophisticated perspectives on social relations, which emphasize the ways in which cultural frameworks as well as institutions condition people's health. It reports on research into health inequalities in the developed and developing worlds, covering a wide range of national case studies, and into the ways in which social relations condition the effectiveness of public policies aimed at improving health.