Experiments in supranational institutionbuilding: The European Commission as a laboratory

International governmental organisations are governed by ministers who have their primary institutional affiliation at the national level. The European Commission represents a notable organisational innovation in the way that executive politicians at the top, i.e. the commissioners, have their primary affiliation to the international level. Thus, the Commission constitutes a laboratory for experiments in supranational institutionbuilding: What is the relative importance of nationality and organisational position as regards explaining actual behaviour? Concerning Commission officials, nationality seems to play a minor role. Nationality matters somewhat more regarding commissioners’ behaviour, but makes up only one of several components of their highly compound role.