The predictors of party group bargaining success in the European Parliament

This article examines the predictors of European Party Groups’ bargaining success in internal negotiations within the European Parliament. It evaluates theories relating to pivotality in the policy space, agenda-setting power, strategic anticipation of interinstitutional bargaining, and internal group cohesion. Understanding these mechanisms is crucial because parliamentary agreements structure trilogue negotiations, ultimately affecting the European Union's legislative outcomes. Drawing on an original interview-based dataset covering 31 legislative proposals in the 9th Parliament (2019–2024), the study directly measures party group preferences and compares them to the positions adopted in parliamentary opinions. The findings show that mandates tend to follow the grand coalition median rather than the body's median as a whole, rapporteurs systematically benefit their groups, and internal cohesion unexpectedly reduces bargaining success. The negative impact of proximity to the Council suggests strategic positioning for trilogues, whereas alignment with the Commission and non-lead committee rapporteurships shows little effect. Together, the results provide a systematic account of bargaining in the modern European Parliament, offering a platform for future research.