Special report on the political and social contexts of health: Part I. Introduction: objectives and purposes of the study.

This article introduces a series of research projects (carried out by the International Network on Social Inequalities and Health) focused on the impact of politics on policy and the consequences for health and quality of life, an area that has been understudied in the social science literature. The introduction describes the conceptual model that guided the research, centered on the study of how political parties and social agents (such as trade unions) affect social inequalities and mortality indicators through labor market and welfare state policies. The major theme of this research is whether political and social interventions matter in health policy and health outcomes. The introduction also describes the different types of research projects carried out by the International Network at the national levels (among OECD countries) and at the regional and local levels (in the United Kingdom, Italy, Germany, Spain, and Sweden). This Journal issue presents the multinational study and the U.K. case study; the next issue will include the Italian, German, Spanish, and Swedish case studies and the summary and conclusions.