This article investigates a widespread yet understudied trend in EU politics: the shift of legislative decision making from public inclusive to informal secluded arenas and the subsequent adoption of legislation as “early agreements.” Since its introduction in 1999, “fast-track legislation” has increased dramatically, accounting for 72% of codecision files in the Sixth European Parliament. Drawing from functionalist institutionalism, distributive bargaining theory, and sociological institutionalism, this article explains under what conditions informal decision making is likely to occur. The authors test their hypotheses on an original data set of all 797 codecision files negotiated between mid-1999 and mid-2009. Their analysis suggests that fast-track legislation is systematically related to the number of participants, legislative workload, and complexity. These findings back a functionalist argument, emphasizing the transaction costs of intraorganizational coordination and information gathering. However, redistributive and salient acts are regularly decided informally, and the Council presidency’s priorities have no significant effect on fast-track legislation. Hence, the authors cannot confirm explanations based on issue properties or actors’ privileged institutional positions. Finally, they find a strong effect for the time fast-track legislation has been used, suggesting socialization into interorganizational norms of cooperation.

How can evolutionary ideas be applied to the study of social and political institutions? Charles Darwin identified the mechanisms of variation, selection and retention. He emphasized that evolutionary change depends on the uniqueness of every individual and its interactions within a population and with its environment. While introducing the contributions to this special issue, we examine some of the ontological positions underlying evolutionary theory, showing why they are appropriate for studying issues in economics, political science and sociology. We consider how these ideas might help us understand both institutional change and the formation of individual preferences.