The Policy Impact of the Court of Justice of the European Union

This chapter focuses on the policy impact of the judgments of the Court of Justice of the European Union. It defines policy impact as the ability of the Court to produce change in the political domain. The chapter analyses this impact across two different dimensions: horizontal and vertical. The horizontal dimension looks at the impact of the Court’s rulings on European Union policies, that is, to what extent the judgments of the Court impact the policy output of the European Union legislator. The vertical dimension focuses on the impact of the Court’s judgments on Member States’ legal orders. This is understood broadly as encompassing change as showing through in legislation, case law, policies, and administrative decisions. The chapter begins by developing a conceptual framework to delimitate what we understand as policy impact. It then systematically reviews the existing literature in this area to systematise existing knowledge and identify lacunas, shortcomings and challenges. Finally, it proposes, based on the strengths and weaknesses of this literature, a new way for thinking about how to empirically study the policy impact of the Court.