Acknowledgements

We thank the National Statistical Institutes ISTAT (Italy), INE (Spain), DESTATIS (Germany), INSEE (France), INE (Portugal), CBS (Netherlands) for providing the original data from the 2011 Census. Data for Ireland and UK was downloaded from publicly available platforms at UK data Archive and IE National archives. Participants undertake to suitably acknowledge the above mentioned National Statistical Institutes - as well as the European Commission's Joint Research Centre - in their output works and in any publication linked thereto.