Opening up by closing off: how increased transparency triggers informalisation in EU decision-making^*

With transparency for EU trade negotiations becoming a high-profile topic this past decade, its connection with EU inter-institutional politics has become more consequential. In response to the changed role of the European Parliament and the need to better inform the public debate, the European Commission has significantly reformed its transparency policy for trade negotiations. At the same time however, an institutional process of informalisation at the EU level has enfolded. This study uses process-tracing methodology to determine how the increased transparency caused this informalisation in the case of the Transatlantic Trade and Investment Partnership negotiations. It thereby seeks to uncover a widely-occurring yet surprisingly underexplored process of institutional change that follows from increased transparency. Contrary to earlier accounts of correlations between transparency and informalisation, the author finds that both concepts are not necessarily contradictory. Instead, informality can in fact contribute to transparency goals and help legitimise decision-making.