An institutional theory of welfare state effects on the distribution of population health

Social inequalities in health endure, but also vary, through space and time. Building on research that documents the durability and variability of health inequality, recent research has turned towards the welfare state as a major explanatory factor in the search for causes of health inequality. With the aims of (i) creating an organizing framework for this new scholarship, (ii) developing the fundamental-cause approach to social epidemiology and (iii) integrating insights from social stratification and health inequalities research, we propose an institutional theory of health inequalities. Our institutional theory conceptualizes the welfare state as an institutional arrangement - a set of 'rules of the game' - that distributes health. Drawing on the institutional turn in stratification scholarship, we identify four mechanisms that connect the welfare state to health inequalities by producing and modifying the effects of the social determinants of health. These mechanisms are: redistribution, compression, mediation and imbrication (or overlap). We describe how our framework organizes comparative research on the social determinants of health, and we identify new hypotheses our framework implies.