Ali and Cochrane Comparative Migration Studies (2024) 12:16 Research based on comparative case study approaches are always limited by the comparability of each case and the extent of detail that is included or excluded for comparison, and this study is no different in that regard. In the following section we have attempted to outline the most relevant similarities and differences of the three country case studies, in relation to the research question. Undoubtedly, additional factors could have been added, however given the scope of a publication of this nature we had to make choices of inclusion and exclusion for consideration. A second limitation of this study is that we have relied upon secondary literature, available data, legal documentation and media reporting and the implications are based upon our own assessment. We have not, but could have, conducted interviews or focus groups with experts and key stakeholders for validation. Future studies could add this form of evidence for validation of these findings. Another option for validation, which we were not able to obtain data to use for validation, would have been specific data on the people pursuing the new pathways to permanence in the three country case studies. If that data becomes available, such an analysis would be able to provide more specific insight into what sorts of applicants are applying for the various residence and immigration pathways. This study could have included other countries, particularly the other member states of the GCC (Bahrain, Kuwait, and Oman). This was not done primarily due to the limitations of space, but also because of more diverse economic, demographic, socio-cultural, and religious factors making for difficulties in the case study comparison method (specifically for the research questions undertaken). The selection of case studies for comparison was done on the basis of policy change (which has occurred in the three selected countries of the GCC), while sharing common traits of the GCC, but not based on a regional study (all GCC member states) or the specific attribute of demographic similarity (one of many potential attributes that could be used for inclusion selection for case studies) per se (despite the similarities noted below). Future research could also compare the directions of those nations and relate that to the results of this study. Country case studies: Saudi Arabia, Qatar, and the UAE In presenting the three country case studies, the first part of each case study outlines the demographics and economy, followed by an analysis (historical and contemporary) of citizenship and residency. The three countries included in this study are members of the GCC, share borders and historically had economic and family ties. The official religion of Saudi Arabia is Islam and Arabic its official language, however due to large and diverse expatriate populations faiths and languages are diverse in the region (each country studies provides more details on these specifics, see below). The hydrocarbon resources of the region have enabled relatively high individual incomes and high economic growth rates, with all three working to diversify their economies beyond sectors related to their hydrocarbon resources. However, in some regards the countries are different. During the era of European colonization, Qatar and the UAE were part of a British protectorate while Saudi Arabia was not. Saudi Arabia has a much larger population than the others, more than three times that of the UAE and more than ten times that of Qatar (see Table 1). Relatedly, Saudi Arabia is geographically much larger in size. While birth rates have declined in the UAE and Qatar, similar to the ‘more developed regions’, that of Saudi Arabia is similar to the higher world average, however that is projected to Page 3 of 17