1 Agenda-setting, concession-trading or problem-solving? The institutional origins of EU legislation Thomas Laloux University of Louvain – Louvain-la-Neuve Institut de sciences politiques Louvain-Europe (ISPOLE) thomas.g.laloux@uclouvain.be Tom Delreux University of Louvain – Louvain-la-Neuve Institut de sciences politiques Louvain-Europe (ISPOLE) tom.delreux@uclouvain.be —— this is a draft paper, please do not quote —— 1. INTRODUCTION In legislative policy-making several institutions need to agree upon the same text in order to adopt legislation. This means that these institutions must find a way to reconcile their initial disagreements. In the EU, the Council and the European Parliament (EP) are the co-legislators, which must find a compromise based on a proposal by the Commission. That compromise is thus composed of text initially proposed by the Commission, amendments that are put forward by the Council and/or the EP, and potentially language that is drafted during the actual interinstitutional negotiations in trilogues. There are, however, different ways by which these elements are integrated into a common text. The co-legislators can follow the proposed text by the agenda-setter, they can trade positions that were established