John Erik Fossum is Professor in Political Science at the ARENA Centre for European Studies at the University of Oslo, Norway.

Markus Jachtenfuchs is Professor of European and Global Governance and the Hertie School of Governance in Berlin, Germany.

1. Federal challenges and challenges to federalism. Insights from the EU and federal states 2. Democratic Federalization and the Interconnectedness - Consent Conundrum 3. Patterns of Multilevel Parliamentary Relations. Varieties and Dynamics in the EU and other Federations 4. Executive-Legislative Relations and Inter-Parliamentary Relations in Federal Systems - Lessons for the European Union 5. Representation in the EU: multi-level challenges and new perspectives from comparative federalism 6. Horizontal coordination in federal political systems - non-centralization in the European Union and Canada compared 7. Intergovernmentalism in the European Union: A Comparative Federalism Perspective 8. Balancing sub-unit autonomy and collective problem-solving by varying exit and voice. An analytical framework 9. Europe as a multilevel federation

Discussing what we may learn from thinking about the EU in federal terms represents a two-fold challenge. It is on the one hand a matter of establishing 'how federal' the EU is (the EU's federal challenge). On the other, the EU has federal features but is not a state, thus raising the question of whether federal theory and practice may have to be adapted to take proper account of the EU (the EU's challenge to federalism). The contributions to this collection supplement and extend existing scholarship through focusing on two important lines of inquiry. The first focuses on the relationship between federalism and democracy, with particular emphasis on how federal systems respond to and deal with citizens' interests and concerns, within and outside the political system. Representation is explored both in the process of federalization, and as a feature of established systems. The second line of inquiry places the emphasis on the relationship among the governments of federal systems. The focus is on intergovernmental relations, and the particular merits that emanate from studying these from a federal perspective. This book was originally published as a special issue of Journal of European Public Policy.