Comparative analyses of citizenship laws has so far been mostly qualitative. Recently, however, several authors have attempted to calculate quantitative indicators to measure how open or inclusive citizenship laws are (MIPEX, Howard 2009, Janoski 2010). We argue that, although valuable, these attempts fail to capture some important characteristics of citizenship. As an alternative, we propose a more disaggregated approach to comparison that considers acquisition by naturalisation as well as birthright, and loss through withdrawal, renunciation and lapse. Based on the EUDO CITIZENSHIP dataset, we can analyse typical configurations of specific provisions for acquisition and loss across countries and across time. A second proposal for future research is to combine macro level data on citizenship and foreigners’ laws with micro level data on migration in order to analyse how citizenship regimes of source and destination countries interact in creating particular combinations of legal statuses and rights attributed to migrants and how these change over time as a result of migrants’ mobility patterns.
