This study was commissioned by the Policy Department for Citizen's Rights and Constitutional Affairs at the request of the LIBE Committee AUTHOR(S) Prof. Gerard-René DE GROOT (Maastricht University) Katja SWIDER, LLM (University of Amsterdam) Dr Olivier VONK (Maastricht University and University of Liège) The authors wish to thank the Centre for European Policy Studies (CEPS) for coordinating this study and Dr Laura VAN WAAS (Institute for Statelessness and Inclusion) for providing detailed comments on an earlier draft. RESPONSIBLE ADMINISTRATOR Ms Sarah SY Policy Department Citizens' Rights and Constitutional Affairs European Parliament B-1047 Brussels E-mail: poldep-citizens@europarl.europa.eu Editorial assistant Ms Lucia-Cristina ACHIHĂEI LINGUISTIC VERSIONS Original: EN ABOUT THE EDITOR Policy Departments provide in-house and external expertise to support EP committees and other parliamentary bodies in shaping legislation and exercising democratic scrutiny. To contact the Policy Department or to subscribe to its monthly newsletter please write to: poldep-citizens@europarl.europa.eu European Parliament, manuscript completed in November 2015. © European Union, 2015. This document is available on the Internet at: http://www.europarl.europa.eu/supporting-analyses DISCLAIMER The opinions expressed in this document are the sole responsibility of the author and do not necessarily represent the official position of the European Parliament. Reproduction and translation for non-commercial purposes are authorized, provided the source is acknowledged and the publisher is given prior notice and sent a copy.