A Cross-National Empirical Analysis of the Contribution of Fertility, Life Expectancy and Net Migration in Driving Contemporary and Future Population Ageing

Population ageing is an unprecedented phenomenon witnessed by nations globally. Given contradictory findings in the literature regarding the major drivers behind this phenomenon, this study presents a robust cross-national empirical analysis of the contributions of fertility, life expectancy, and net migration to driving contemporary and future population ageing. The study addresses endogeneity and serial correlation by employing dynamic cointegrating regressions, specifically Fully Modified Ordinary Least Squares (FMOLS) and Dynamic Ordinary Least Squares (DOLS), based on data extracted from the United Nations Population Division for 72 nations spanning two periods: 1960-2020 and 2020-2050. The results indicate that nations in advanced ageing transitions, primarily developed nations, experienced comparatively lower fertility rates and higher life expectancy rates than those in early stages, with fluctuations observed in net migration. A statistically significant long-run dynamic cointegrating relationship is found among the three major drivers and population ageing. Declining fertility has been the primary driver of global population ageing from 1960 to 2020, followed by increasing life expectancy and, lastly, net migration. These results remain robust across the four sub-panels of nations based on age-transition categories. Projections suggest that population ageing will persist as a reality. However, regression estimates indicate that life expectancy will surpass fertility to become the primary driver of ageing in the future. The study raises doubt about the rejuvenating role of migration as a solution to population ageing and underscores the importance of further research in this area.