The core or the winset? Explaining decision-making duration and policy change in the European Union

This article examines to what extent different formal conceptualizations of ideological conflict can help to explain the capacity for and speed of policy change in the European Union (EU). We compare the core and the winset, two competing concepts based on the spatial theory of voting. The empirical analysis shows that the latter concept bears a strong and systematic influence on decision making in the EU. The smaller the winset containing the outcomes that a majority of actors in the Council of the EU prefers over the status quo, the longer a decision-making process lasts and the smaller the potential for policy change.