1Since 2015, Population has published regular chronicles reviewing current knowledge on a particular population issue of global importance. These chronicles aim to provide a wide audience (of scientists, students, journalists, policymakers, and others) with a synopsis of both the data and the key elements of theoretical, methodological, and political debate. They contextualize the issue and provide a historical perspective.
2After a critical description of information sources and measurement tools, the authors review the most recent research on the topic and describe overall trends along with any social, spatial, and gender disparities. This is followed by a discussion on the potential political or legal implications of current and future situations, and the challenges for future research.
3Previous chronicles have focused on key demographic topics such as the masculinization of births (No. 3, 2015), female genital mutilation (No. 3, 2016), mortality inequalities in low-income countries (No. 2, 2017), and abortion worldwide (No. 2, 2018). This latest chronicle looks at population ageing.
4Although demographic ageing is occurring in all countries of the world, situational disparities mean that the issues generated in countries that are still very young, such as the countries of the Global South, are very different from those faced by the populations of European countries, North America, or Japan, for example. In these developed countries, the process of population ageing is already well under way, although the timing and magnitude of the phenomenon may vary. With life expectancy continuing to rise and the large baby boom generations reaching older ages, the population is inexorably ageing, posing many challenges for the whole of society: individuals, families, institutions, and governments. Research in demography, economics, and sociology sheds light on these issues.
5Looking at a group of 40 ‘high-longevity’ countries that are relatively homogeneous in terms of health, social, and economic development, the authors describe the current and future situation and provide a wealth of documentation on key questions: How can this ageing be measured? Which indicators are the most relevant for comparing countries and forecasting future trends? What are the demographic dynamics of ageing and its rate of change? Who benefits from increases in life expectancy? What are the health conditions of older people? How are they supported and cared for? What roles should families and institutions play in the provision of this care? How are pension systems adapting to increases in the numbers of older people?