EXPLAINING POLARISATION IN THE EU 27’S INTERNATIONAL MIGRATION DISTRIBUTION MARÍA HIERRO, ADOLFO MAZA & JOSÉ VILLAVERDE Department of Economics, Avda. Los Castros, s/n, University of Cantabria, Spain. E-mail: maria.hierro@unican.es; adolfo.maza@unican.es; villavej@unican.es Received: March 2011; accepted October 2011 ABSTRACT This paper is aimed at analysing the European Union’s international migration distribution (EUIMD) for the period 1990–2010. Besides some relevant aspects of the distribution, such as inequality and dynamics, it mainly focuses on trends in polarisation and in exploring some key factors that might be behind these trends. The results of the study reveal that polarisation in EUIMD has followed a decreasing path and that factors like geographic location and government expenditure on health are those which better explain the polarisation phenomenon. Key words: International migration, intra-distribution dynamics, polarisation, explained polari- sation, geographic location, EU 27 INTRODUCTION International migration issues are at the fore- front of the political debate in the European Union (EU) since the mid-1990s or even earlier. The Maastricht Treaty of 1992, followed by the Amsterdam Treaty signed in 1997, set the grounds for the challenging task of improv- ing European co-ordination related to immi- gration policies. This challenge has recently been fuelled by the unprecedented scale of international migration, basically for control- ling effectively large flows of irregular immigra- tion and safeguarding the internal security of the enlarged EU. Thus, studies portraying immigration experiences in a diverse array of European countries have proliferated in recent years in the literature on international migra- tion (for a survey see Zimmermann 2005). However, and although some contributions to this analysis have been made, an examination of the EU-wide international migration distri- bution is still a question in need of further research. Indeed, the issue of how international migra- tion distribution has evolved in Europe in the context of socio-economic globalisation is of major interest. From a theoretical point of view, globalisation is expected to produce growing and more geographically diversified inter- national migration flows. However, there is a general consensus among researchers that noticeable increases on international migra- tion flows have been more the exception than the rule in the world process of socio-economic globalisation (Tapinos & Delaunay 2000; Pécoud & Guchteneire 2006). The reason is quite simple: the population from developing countries face ever-growing hurdles in its attempt to migrate to developed ones, as most of these potential host countries have rein- forced their controls in the last decades in response to (potential or actual) threats of massive migration inflows (Zimmermann 1995). As for the specific case of the EU, however, this strategy for a policy of ‘closed doors’ has not been completely widespread since, as pointed out by Hierro (2012), most Tijdschrift voor Economische en Sociale Geografie – 2012, DOI:10.1111/j.1467-9663.2011.00694.x © 2012 The Authors Tijdschrift voor Economische en Sociale Geografie © 2012 Royal Dutch Geographical Society KNAG Published by Blackwell Publishing Ltd., 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA