This book, adopting a law in context approach, deals with the controversial development of increased differentiation in European Union law.

Differentiation was at first not perceived as a threat to the European project, but rather as a tool to promote further integration. Today, more EU policies than ever are marked by concentric circles of integration and a lack of uniform application. As the EU faces increasingly existential challenges, this timely book considers whether the proliferation of mechanisms of flexibility has contributed to this newly fragile state or whether, to the contrary, differentiation has been fundamental to integration despite the heterogeneity of national interests and priorities.

"The Routledge Handbook of Differentiation in the European Union offers an essential collection of ground-breaking chapters reflecting on the causes and consequences of this complex phenomenon. With contributions from key experts in this sub-field of European Studies, it will become a key volume used for those interested in learning the nuts and bolts of differentiation as a mechanism of (dis)integration in the European Union, especially in the light of Brexit. Organised around five key themes, it offers an authoritative 'encyclopaedia' of differentiation and addresses questions such as:

The Law of the European Union is a complete reference work on all aspects of the law of the European Union, including the institutional framework, the Internal Market, Economic and Monetary Union and external policy and action. Completely revised and updated, with many newly written chapters, this fifth edition of the most thorough resource in its field provides the most comprehensive and systematic account available of the law of the European Union (EU). Written by a new team of experts in their respective areas of European law, its coverage incorporates and embraces many current, controversial, and emerging issues and provides detailed attention to historical development and legislative history of EU law. Topics that are constantly debated in European legal analysis and practice are touched on in ways that are both fundamental and enlightening, including the following: .powers and functions of the EU law institutions and relationship among them; .the principles of equality, loyalty, subsidiarity, and proportionality; .free movement of persons, goods, services, and capital; .mechanisms of constitutional change – treaty revisions, accession treaties, withdrawal agreements; .budgetary principles and procedures; .State aid rules; .effect of Union law in national legal systems; .coexistence of EU, European Convention of Human Rights (ECHR), and national fundamental rights law; .migration and asylum law; .liability of Member States for damage suffered by individuals; .competition law – cartels, abuse of dominant position, merger control; .social policy, equal pay, and equal treatment; .environmental policy, consumer protection, public health, cultural policy, education, and tourism; .nature of EU citizenship, its acquisition, and loss; and .law and policy of the EU’s external relations. The fifth edition embraces many new, ongoing, and emerging European legal issues. As in the previous editions, the presentation is notable for its attention to how the law relates to economic and political realities and how the various policy areas interact with each other and with the institutional framework. The many practitioners and scholars who have relied on the predecessors of this definitive work for years will welcome this extensively revised and updated edition. Those coming to the field for the first time will instantly recognize that they are in the presence of a masterwork that can always be turned to with profit and that helps in understanding the rationale underlying any EU law provision or principle.

Far from displaying a uniform pattern of integration, the European Union varies significantly across policy areas, institutional development and individual countries. Why do some policies such as the Single Market attract non-EU member states, while some member states choose to opt out of other EU policies? In answering these questions, this innovative new text provides a state-of-the-art introduction to the study of European integration. The authors introduce the most important theories of European integration and apply these to the trajectories of key EU policy areas – including the single market, monetary policy, foreign and security policy, and justice and home affairs. Arguing that no single theory offers a completely convincing explanation of integration and differentiation in the EU, the authors put forward a new analytical perspective for describing and explaining the institutions and policies of the EU and their development over time. Written by a team of prominent scholars in the field, this thought-provoking book provides a new synthesis of integration theory and an original way of thinking about what the EU is and how it works.

The introduction by the Amsterdam Treaty of the flexibility clauses, authorising a majority of Member States to cooperate more closely in areas covered by the Treaties, has been received with mixed feelings. Flexibility is by no means a new phenomenon in the EU's development. It has been on the Community's agenda already since the 1970s. The Single European Act introduced several provisions allowing for flexible approaches to the single market, whilst the Maastricht Treaty launched a differentiated approach to the EMU and social policy. In addition to these forms of differentiation in primary Community law, for many years there has also been a number of quite important, though less visible, forms of differentiation in secondary Community law. This book aims to link both levels of differentiation and seeks to unveil the many faces of differentiation in EU law. It analyses whether, and to which extent, there is a shift in European integration from a system of unity and uniformity to one of flexibility and differentiation. A first series of contributions to the book analyse a number of exemplary policy fields (EMU, social policy, environment, free movement of persons, justice and home affairs) in order to identify their degree of differentiation. A second set of contributions examine various 'horizontal' institutional matters of cross-sectoral importance. These two main parts are framed by introductory articles on the development of flexibility and by contributions drawing on the constitutional limits to differentiation. The contributions are made by Dominik Hanf, José M. de Areilza, Jean-Victor Louis, Sean Van Raepenbusch, Ludwig Kramer, Georgia Papagianni, Grainne de Burca, Ellen Vos, Linda Senden, Sacha Prechal, Wouter Devroe, Deirdre Curtin, Bruno De Witte, Eddy De Smijter en Jan Wouters.

Differentiated integration has become a durable feature of the European Union and is a major alternative for its future development and reform. This book provides a comprehensive conceptual, theoretical, and empirical analysis of differentiation in European integration. It explains differentiation in EU treaties and legislation in general and offers specific accounts of differentiation in the recent enlargements of the EU, the Eurozone crisis, the Brexit negotiations, and the integration of non-member states. Ever Looser Union? introduces differentiated integration as a legal instrument that European governments use regularly to overcome integration deadlock in EU treaty negotiations and legislation. Differentiated integration follows two main logics. Instrumental differentiation adjusts integration to the heterogeneity of economic preferences and capacities, particularly in the context of enlargement. By contrast, constitutional differentiation accommodates concerns about national self-determination. Whereas instrumental differentiation mainly affects poorer (new) member states, constitutional differentiation offers wealthier and nationally oriented member states opt-outs from the integration of core state powers. The book shows that differentiated integration has facilitated the integration of new policies, new members, and even non-members. It has been mainly 'multi-speed' and inclusive. Most differentiations end after a few years and do not discriminate against member states permanently. Yet differentiation is less suitable for reforming established policies, managing disintegration and fostering solidarity, and the path-dependency of core state power integration may lead to permanent divides in the Union.