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

We test two of the main explanations of the formation of political ties. The first 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. Our data consist of a unique combination of actors' policy positions and their network relations over time in the Council of the European Union. We find evidence that both types of explanations matter, although there seems to be variation in the extent to which preference similarity affects network evolution. We consider the implications of these findings for understanding the decision-making in the Council.