The politics of justification? Applying the 'Discourse Quality Index' to the study of the European Parliament

In this paper, we apply a revised version of the Discourse Quality Index (DQI) developed by Steenbergen et al. to European Parliament (EP) debates. This updated measurement instrument, after the inclusion of new indicators, helps us identify not just the principles of European Union (EU) deliberation but most importantly the favourable contextual conditions of supranational deliberation. We illustrate the new DQI coding for selected debates over the last EU parliamentary term and discuss how the data can be employed to assess the overall quality of deliberation in the EP. At the same time we demonstrate that institutional issues matter for the quality of EP discourse, as do Members of the European Parliaments' personal characteristics. Issue attributes on the other hand, influence supranational deliberation but not in the expected direction.