Chameleon pluralism in the EU: an empirical study of the European Commission interest group density and diversity across policy domains

This paper contributes to the discussion surrounding interest groups in the European Commission. We inspect the Commission's lobbying register and assess the density and diversity of the interest group population per policy domain. The results suggest that while at the system level elite pluralism with its preponderance of business interests is a credible hypothesis, this is not the case at the sub-system level, where chameleon pluralism better conceptualizes variation of the interest group populations as a function of the age of the Directorate General (DG), capacity of the DG, nature of the policy domain, and involvement of member states. Bridging theoretical considerations on input/output legitimacy with informational approaches, we argue that different policy domains demand different types of legitimacy that are supported by the provision of different types of information (technical/political).