A new focus within both social epidemiology and political sociology investigates how political systems and priorities shape health inequities. To advance-and better integrate-research on political determinants of health inequities, the authors conducted a systematic search of the ISI Web of Knowledge and PubMed databases and identified 45 studies, commencing in 1992, that explicitly and empirically tested, in relation to an a priori political hypothesis, for either 1) changes in the magnitude of health inequities or 2) significant cross-national differences in the magnitude of health inequities. Overall, 84% of the studies focused on the global North, and all clustered around 4 political factors: 1) the transition to a capitalist economy; 2) neoliberal restructuring; 3) welfare states; and 4) political incorporation of subordinated racial/ethnic, indigenous, and gender groups. The evidence suggested that the first 2 factors probably increase health inequities, the third is inconsistently related, and the fourth helps reduce them. In this review, the authors critically summarize these studies' findings, consider methodological limitations, and propose a research agenda-with careful attention to spatiotemporal scale, level, time frame (e.g., life course, historical generation), choice of health outcomes, inclusion of polities, and specification of political mechanisms-to address the enormous gaps in knowledge that were identified.http://epirev.oxfordjournals.org/content/31/1/152.abstract