Schmid Comparative Migration Studies (2020) 8:25 Bosniak, L. (2006). The citizen and the alien. Princeton: Princeton University Press. Boucher, A., & Gest, J. (2015). Migration studies at a crossroads. Migration Studies, 3(2), 182–198. Boucher, A., & Gest, J. (2018). Crossroads. Cambridge: Cambridge University Press. Brubaker, R. (1992). Citizenship and nationhood in France and Germany. Cambridge: Harvard University Press. Carens, J. (2013). The ethics of immigration. New York: Oxford University Press. Cornelius, W., et al. (2014). Controlling immigration. Stanford: Stanford University Press. Dauvergne, C. (2004). Sovereignty, migration and the rule of law in global times. Modern Law Review, 67(4), 588–615. de Haas, H., Natter, K., & Vezzoli, S. (2015). Conceptualizing and measuring migration policy change. Comparative Migration Studies, 3(15), 1-21. de Haas, H., Natter, K., & Vezzoli, S. (2016). Growing restrictiveness or changing selection? International Migration Review, 52(2), 324–367. Džankić, J. (2019). The global market for investor citizenship. Cham: Palgrave Macmillan. Fitzgerald, J., Leblang, D., & Teets, J. (2014). Defying the law of gravity. World Politics, 66(3), 406–445. Freeman, G. (1995). Modes of immigration politics in Liberal democratic states. International Migration Review, 29(4), 881–902. Goodman, S. (2010). Integration requirements for integration's sake? Journal of Ethnic and Migration Studies, 36(5), 753–772. Goodman, S. (2014a). Immigration and integration policies in Europe. In J. Magone (Ed.), Routledge handbook of European politics. Hoboken: Taylor and Francis. Goodman, S. (2014b). Immigration and membership politics in Western Europe. New York: Cambridge University Press. Hammar, T. (1985). European immigration policy. Cambridge: Cambridge University Press. Hammar, T. (1990). Democracy and the nation state. Aldershot: Ashgate. Hampshire, J. (2013). The politics of immigration. Cambridge: Polity Press. Helbling, M., & Kalkum, D. (2018). Migration policy trends in OECD countries. Journal of European Public Policy, 25(12), 1779–1797. Helbling, M., et al. (2017). Measuring immigration policies: The IMPIC database. European Political Science, 16(1), 79–98. Hollifield, J. (1992). Immigrants, markets, and states. Cambridge: Harvard University Press. Hollifield, J. (2004). The emerging migration state. International Migration Review, 38(3), 885–912. Hollifield, J., & Faruk, R. (2017). Governing migration in an age of globalization. In G. Carolus et al. (Eds.), Migration on the move (pp. 118–145). Leiden: Brill. Howard, M. (2009). The politics of citizenship in Europe. New York: Cambridge University Press. Huddleston, T., & Niessen, J. (2011). Migrant integration policy index. Brussels: British Council and Migration Policy Group. Huddleston, T., & Vink, M. (2015). Full membership or equal rights? Comparative Migration Studies, 3(8), 1-19. Jolliffe, I. (2002). Principal component analysis. New York: Springer. Joppke, C. (1998). Why Liberal states accept unwanted immigration. World Politics, 50(2), 266–293. Joppke, C. (2001). The legal-domestic sources of immigrant rights. Comparative Political Studies, 34(4), 339–366. Joppke, C. (2008). Comparative citizenship. Law & Ethics of Human Rights, 2(1), 1–41. Joppke, C. (2010). Citizenship and immigration. Cambridge: Polity Press. Koopmans, R. (2013). Indices of immigrant rights. Comparative European Politics, 11(5), 696–703. Koopmans, R., Michalowski, I., & Waibel, S. (2012). Citizenship rights for immigrants. American Journal of Sociology, 117(4), 1202–1245. Koopmans, R., et al. (2005). Contested citizenship. Minneapolis: University of Minnesota Press. Linting, M., et al. (2007). Nonlinear principal components analysis. Psychological Methods, 12(3), 336–358. Lutz, P. (2019). Reassessing the gap-hypothesis. In Party Politics online first. Meulman, J., & Heiser, W. (2005). Categories 14.0. Chicago: SPSS. Neumayer, E. (2005). Bogus Refugees? International Studies Quarterly, 49(3), 389–410. Peters, M. (2017). Trading Barriers. Princeton: Princeton University Press. Ruhs, M. (2013). The Price of rights. Princeton: Princeton University Press. Sassen, S. (1996). Beyond sovereignty. Social Justice, 23(3), 9–20. Schmid, S.D., & Helbling, M. (2016). Validating the Immigration Policies in Comparison (IMPIC) Dataset. WZB Social Science Center, Berlin: WZB Discussion Paper SP VI 2016–202. Schmid, S.D., Piccoli, L., Arrighi, J.-T. (2019). Non-universal suffrage. European Political Science, 18, 695–713. Shachar, A. (2018). The marketization of citizenship in an age of restrictionism. Ethics & International Affairs, 32(1), 3–13. Spiro, P. (2011). A new international law of citizenship. American Journal of International Law, 105, 694. Stadlmair, J. (2017). Which policies matter? Österreichische Zeitschrift für Politikwissenschaft, 46(1), 60-73. Vink, M. (2017). Comparing citizenship regimes. In A. Shachar, R. Bauböck, I. Bloemraad, & M. Vink (Eds.), The Oxford handbook of citizenship (pp. 221–245). Oxford: Oxford University Press. Vink, M., & Bauböck, R. (2013). Citizenship configurations. Comparative European Politics, 11(5), 621–648. Walzer, M. (1983). Spheres of justice. New York: Basic Books. Weber, M. (1946). From max Weber: Essays in sociology. New York: Oxford University Press. Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Page 20 of 20