Benchmarking the Protection against Statelessness 295 Keywords comparative nationality law – statelessness – international law – EUDO citizenship – UNHCR 1 Introduction to the EUDO Citizenship-UNHCR Collaboration on Statelessness in Europe Considerable progress has been made in recent years in mapping the problem of statelessness in Europe.1 But where many studies take a broad approach that looks at this phenomenon from different perspectives, including migration law, non-removability, and detention, it often remains unclear if and how the nationality laws of different European countries offer protection against statelessness.2 A timely contribution to this field of research, therefore, is an online database – developed by the European Union Democracy Observatory on Citizenship (EUDO Citizenship) in collaboration with the United Nations High Commissioner for Refugees (UNHCR) – that contains information on the extent to which citizenship laws in 36 European states provide sufficient protection against statelessness, in light of the most important international standards.3 While the purpose of the database is to offer concise and easily accessible analyses of national legislation so as to make possible cross-country comparisons, a complementary EUDO Citizenship comparative report elaborates in greater detail on the issues raised by the database.4 The aim of this short contribution is to present the key findings of this EUDO-UNHCR collaboration on statelessness in Europe. Before doing so, however, we first pay attention to the comparative methodology used in creating the database. 1 UNHCR mapping studies were published in recent years in the UK and the Netherlands (2011) as well as in Belgium (2013). 2 The terms nationality and citizenship are used interchangeably in this article. 3 O Vonk, M Vink and GR de Groot (2013). EUDO CITIZENSHIP/UNHCR Database on Protection against Statelessness in Europe. San Domenico di Fiesole: Robert Schuman Centre for Advanced Studies, European University Institute, available at http://eudo-citizenship.eu/ databases/protection-against-statelessness (last accessed on 3 November 2013). 4 O Vonk, M Vink and GR de Groot (2013). Protection against Statelessness: Trends and Regulations in Europe. EUDO Citizenship comparative report, available at http://eudo citizenship.eu/images/docs/eudocit_vink_degroot_statelessness_final.pdf (last accessed on 3 November 2013). tilburg law review 19 (2014) 294-302