Ali and Cochrane Comparative Migration Studies (2024) 12:16 Page 4 of 17 Table 1 Population projections (medium variant), millions (UNSD, 2022) Country 2020 2050 2100 Qatar 2.8 3.9 4.1 Saudi Arabia 35 45 42 UAE 9.9 10.5 9.0 Table 2 Fertility rates/live births per woman (medium variant), millions (UNSD, 2022) Country 2020 2050 2100 Qatar 1.781 1.658 1.655 Saudi Arabia 2.393 1.884 1.725 UAE 1.443 1.495 1.585 ‘More Developed Regions’ 1.528 1.637 1.674 World 2.314 2.149 1.835 change in the coming decades (see Table 2 and contextualization of this data below). Each of the three are discussed in detail in the follow sub-sections. There are few nations in the world that have as high a percentage of the population of expatriates as the Gulf nations (the specifics are noted in the country sections that follow). This context can create challenges when analyzing demographic data (as in Tables 1 and 2; see Shah, 2017). Take Qatar as an example, where citizens make up an approximate 12% of the population and where expatriates are the majority: the fertility rate listed by the United Nations is an aggregate figure of the citizen and resident population, which alters the fertility rate due to a large number of adults (both male and female) who are working in the country without their families and/or are unmarried. The official fertility rate of Qatari women in 2020 was 2.5 (PSA, 2020), while the United Nations data (as shown in Table 2) lists 1.781. That is not to suggest the data is incorrect per se, rather it is to clarify who the data includes, and the limitations and/or meaning of these datasets. In the case of Qatar, both the total population fertility rate and the citizen fertility rate are declining, and thus the general point about a declining trend remains. Saudi Arabia Demographics and economy Within the GCC, Saudi Arabia is geographically the largest and has the largest population. It has a population of approximately 35 million people (World Bank, 2023). More than a third of Saudi’s population is made up of expatriates. In 2021, the expatriate population was 13.49 million. The majority of the population is under the age of 30, with a median age of 30.8 years (World Population Review, 2023). Saudi Arabia is home to the largest economy in the GCC, with the oil and gas sector being the primary driver of economic growth (46% of GDP and nearly all export revenues; Trading Economics, 2023). However, the government is working to diversify the economy, and it is doing so by investing in sectors such as tourism, technology, and renewable energy (EpoD, 2019). These diversifications are outlined in the 2030 Vision, for which foreign investment (and enablers thereof ) is expected to play an important role. However, the country faces