Who cares about nationality? The path-dependent case law of the ECJ from goods to citizens

The role that the ECJ plays in European integration has been much discussed by political scientists. Less is known about how case law develops. In this contribution, I give a historical-institutionalist account and argue that path dependence explains the course that case law takes. Litigants provide positive feedback in this process, aiming to strengthen their rights by transferring legal arguments from one area to the next, leading to a convergent interpretation of the fundamental freedoms. The paper traces this development, analyzing how legal arguments were transferred from goods markets to the free movement of workers and citizenship as a result of positive feedback to a distinct legal interpretation. I discard alternative explanations that explain case law by drawing on the preferences of member states or judges.