1 Supranational Influence in the Reform of the Eurozone * Magnus Lundgren Stockholm University magnus.lundgren@statsvet.su.se Jonas Tallberg Stockholm University jonas.tallberg@statsvet.su.se Fabio Wasserfallen University of Salzburg fabio.wasserfallen@sbg.ac.at Paper for presentation at the PEIO Conference, February 7 – 9, 2019, Salzburg Abstract When, why and how are the European Commission, the European Central Bank, and the European Parliament influential in European Union (EU) policy-making? This paper addresses this classic question of EU studies through a systematic, empirical analysis of supranational influence in the reform of the Eurozone, 2010-2015. We develop theoretical expectations about the determinants of supranational influence, privileging the strategic setting of EU decision- making and the characteristics of member states. Empirically, we draw on unique data on 39 contested policy issues negotiated during the Eurozone crisis to measure and explain supranational influence. Methodologically, we pioneer a novel relational measure of supranational influence vis-à-vis individual member states that we analyze with cross-nested hierarchical models. The central findings of our analysis are three-fold. First, the Commission and, to a lesser extent, the European Central Bank and the European Parliament greatly influenced negotiated outcomes. Second, the institutions were particularly influential when decisions were adopted through procedures granting them a larger role in policy-making. Third, the institutions were more influential in relation to member states with greater voting power, less network capital, higher economic vulnerability, and lower issue salience. These findings suggest that supranational influence remains an important feature of EU politics, even on a highly contested issue such as Eurozone reform. * This research is part of the project ‘EMU Choices’ funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 649532. We thank Meltem Müftüler Bac, Ludvig Norman, Frank Schimmelfennig, Uwe Puetter, and Amy Verdun, for helpful comments on earlier drafts.