Introduction: Decision-Making in the European Union before and after the Lisbon Treaty

The Lisbon Treaty (2007) entered into force on 1 December 2009. It foresaw a number of changes in institutional relations and decision-making between the European Union (EU) institutions on the one hand and between the EU and its member states on the other. This special issue of West European Politics (WEP) focuses on decisionmaking in the European Union before and after the Lisbon Treaty (DEUBAL). It mainly aims to assess what the changes were on particular subject areas that the Treaty of Lisbon envisaged and whether these ambitions have materialised since the Treaty entered into force. In other words, some of the DEUBAL papers offer both analyses of the past and of what the future may hold in light of these changes (and some of them may in fact only take effect in years to come). Others do not focus on the past but examine the extent to which the current decisionmaking process has been able to address the shortcomings and challenges of the past since the Lisbon rules entered into force and new practices have emerged. Included in this last category are also studies that examine the impact of aspects of the Lisbon Treaty that clarified pre-existing norms and structures, in some cases formalising them, rather than introducing new changes. The authors in this project all look at the interaction between formal rules and informal practices, seeking to point to the interaction between the two. They each adopt a loosely rationalist institutionalist approach, attributing rationality to actors (March and Olsen 1989). It is rationalist not so much in opposition to sociological institutionalism or to constructivism, but because authors attribute utility-maximising efforts to actors. In other words, actors seek to maximise their influence, and use the institutional structure for their own interests. If not, the assumption is that there is a good reason why they do not. The DEUBAL papers focus on different institutional aspects of changes to decision-making since Lisbon (basically comparing before and after). A