This volume presents different scenarios of future population and human capital trends in 201 countries of the world to the end of this century to inform the assessment of possible future migration patterns into the EU as currently carried out by the Centre of Expertise on Population and Migration (CEPAM) Project (collaboration between JRC and IIASA).
The study also goes beyond the conventional population projections which only consider the age and sex structures by taking a multi-dimensional approach through adding educational attainment for all countries and also labor force participation for EU member states. The definition of scenarios in this study follows the narratives of the SSPs (Shared Socioeconomic Pathways) which are widely used in the global change research community. The Medium scenario (SSP2) foresees that fertility and mortality follow a medium pathway that can be seen as most likely from today’s perspective. The scenario of Rapid Development (SSP1) assumes rapid increases in life expectancy, a faster fertility decline in high fertility countries and an education expansion path that follows the education goals as given by the SDGs (Sustainable Development Goals). The Stalled Development scenario (SSP3) presents divided world foreseeing a stall in educational expansion in developing countries as well as continued high fertility and high mortality. Moreover, these scenarios also serve policy considerations in many other fields ranging from the economic consequences of population ageing to development priorities in Africa, global population and environment interactions.
This volume also serves as an update of the scenarios presented in the 2014 Oxford University Press book entitled “World Population and Human Capital in the 21st Century” (Lutz et al 2014), which includes the most comprehensive summary of different possible scientific arguments underlying the assumptions of future fertility, mortality, migration and education trends in different parts of the world with input from over 550 population experts. This new 2018 assessment also has a new 2015 baseline and adjusts the near term (up to 2030) fertility and mortality assumptions accordingly while maintaining the long term assumptions as justified in the 2014 book. In terms of migration, it combines three rough migration assumptions – zero migration, constant rates as observed over the past 60 years and double those rates – with medium fertility and mortality trends to illustrate the sensitivity of longer term population trends to alternative migration intensities.
In terms of global level results, in the Medium scenario, world population would continue to increase until around 2070-80 when it would reach a maximum level of around 9.8 billion before starting a slow decline, reaching about 9.5 billion by the end of the century. This projected increase is lower than the recent United Nations projections based on a different model and higher than in the above mentioned 2014 book which uses the same long term assumptions. An important reason for increase in the outlook lies in the fact that child mortality, particularly in Africa, declined more rapidly than was previously assumed by all international projections. In demographic terms, a decline in child mortality has the same effect on the number of surviving children as an increase in fertility. Hence, already the population baseline of 2015 was markedly higher than had been projected on the basis of the 2010 baseline, which was used in the previous assessment.
However, in the long run demography is not destiny and alternative scenarios show a broad range of possible futures. Assuming rapid social development (SSP1), in particular a rapid expansion of education following the Sustainable Development Goals, world population would after a further increase start to decrease, showing a peak population of around 8.9 billion in 2055-60 and a decline to 7.8 billion by the end of the century. Assuming on the other hand stalled social development (SSP3) and thus lower female education and higher fertility rates for each education group, world population already reaches the 10 billion mark around 2045 and then continues to grow over the rest of the century reaching 13.4 billion in 2100. This scenario is also likely to be associated with wide-spread poverty and weak resilience to already unavoidable environmental change.
As to the European Union, projected population size under the Medium scenario of EU28 in 2060 is very close to the current baseline of 2015, namely around 507 million inhabitants. However, the trajectory of change would have a convex shape reaching a maximum 512 million people around the year 2035. While the initial increase is mostly a consequence of assumed immigration to the EU the following decline results from persistent sub-replacement fertility levels which will have developed a negative growth momentum through an age structure with fewer young people. Under the scenario of Zero Migration the population of the EU-28 would decline to around 460 million by 2060, while under the Double Migration scenario it would increase to 550 million. Under all scenarios the population of the EU28 shows significant ageing, which is more pronounced under low fertility and low immigration assumptions. However, the scenarios that explicitly consider education and labor force participation also show that the total labor force in Europe does not necessarily shrink, if labor force participation around the EU would approach that of Sweden today and that the future labor force could also be more productive.
The population of Sub-Saharan Africa, on the other hand, is likely to more than double by 2060 from currently around 1 billion to 2.2 billion under the Medium scenario and even 2.7 billion under the stalled development SSP3 scenario. Hence, with the demographic transition in Asia well advanced, the future of world population growth will largely be decided in Africa with the future education of women as a main determinant of fertility playing a key role. There has been recent moderate progress in education expansion but continued progress is not guaranteed, despite the fact that today in virtually all countries the young generations are better educated than the older ones. But as shown by the stalled development (SSP3) scenario the combination of high population growth with no further schooling expansion can actually result in an increase of the proportion without any formal education even at the global level from 10 to 22 percent by the end of the century. This possible stall in education will not only accelerate population growth but also likely be associated with widespread poverty and high vulnerability to already unavoidable climate change.
The combined trends of decreasing fertility and increasing life expectancy would lead to continued population ageing in the world in the future. The world will be significantly older. In all scenarios presented in the report, as well as those used by United Nations, the share of older people increases over time. For example, in our Medium scenario the percentage of those aged 65 and more increases from around 8% in 2015 to 20% by 2060. In the European Union, the share of older people will grow from around 20% in 2015 to 32% in 2060 according to medium scenario. In 2060 half of the population in this region will be at an age of at least 50 years. A particularly dynamic process would be observed in Eastern European member states where lower fertility and high life expectancy is accompanied with high volume of emigration accelerating ageing if the current trends continue. These structural changes would lead to significant socio-economic challenges for societies in the future.