ABSTRACT
Political opportunity structure (POS) describes the political and institutional opportunities and constraints that either inhibit or facilitate collective action. For example, an important criterion of difference is seen to be that between federal and centralised political constitutional forms. In this analysis countries with federal constitutions (USA, Germany) that grant local decision-making rights to regional assemblies are seen as more open to certain forms of social movement intervention than countries like the United Kingdom (until 2001) and France where the central state dominates. POS approaches are closely aligned with rational choice theories and complementary to resource mobilisation theory.
