The evolution of political networks : evidence from the Council of the European Union

This study tests two of the main explanations of the formation of political ties. The first explanation is based on the homophily principle and states that political actors are more likely to form a relationship if they have similar policy preferences. The second explanation, from network theory, predicts that the likelihood of a tie between two actors depends on the presence of certain relationships with other actors. For instance, two actors are more likely to form a tie if they share many transitive linkages with other actors. We examine the evolution of cooperation networks in the Council of the European Union as a testing ground for propositions from these approaches. Our data consist of a unique combination of actors’ policy positions and their network relations over time. We find evidence that both preference similarity and indirect ties affect the development of network relations throughout the Council's committees, although there appears to be significant variation in the extent to which preference similarity affects network evolution. We consider the implications of these findings for the stock of social capital held in the Council and for understanding the consensual mode decision-making highlighted by previous studies of the Council. These issues are highly pertinent given the challenges posed by the prospect of Brexit