Demographic changes – such as in the number, age composition and spatial distribution of the population – are one of the megatrends of our times. They have profound implications for societies and are a major priority for many countries around the world.
These changes affect key development goals, with implications for labour markets, pensions, social protection, health, education, infrastructure, environment, economic growth, government budgets and public debt, among others.
Over the past decades, the world has witnessed new dynamics in mortality, fertility and migration. Not only is there a significant improvement in life expectancy – owing especially to a fall in infant and child mortality – but there is also a decline in fertility rates and accelerated human mobility and migration within and between countries. Together, these factors have had profound effects on population dynamics across the world.
While the global population will continue to grow for decades to come, there are notable differences in demographic realities between countries. For example, the number of countries experiencing high fertility and rapid population growth is declining, and is now largely concentrated in sub-Saharan Africa and South Asia. And the number of countries with low fertility and slow, stagnant or negative population growth is rising. More than two thirds of the world’s population now lives in countries where the total fertility rate falls below the approximate replacement level of 2.1 children per woman. The replacement level is the average number of children a woman needs to have for a population to replace itself from one generation to the next.
Meanwhile, population ageing has become a universal phenomenon and is projected to occur more rapidly in middle-income countries, where the share of people aged 65 and over is expected to double over the next three decades. And population ageing will, in a growing number of countries, lead to population decline.
While population decline is not a new phenomenon – it has happened before mostly in the context of famines and wars – persistent population decline is a new reality. And although countries in Europe and Asia are leading the world into this new, unchartered phase of the demographic transition, over the coming years, others from all regions will follow suit.
Many governments have expressed concern about their demographic futures, and many are embarking on policies that aim to increase birth rates. While such policies can be perfectly compatible with fundamental human rights and choices when they support women and men to achieve their fertility aspirations, some responses threaten to undermine hard-won progress on gender equality and reproductive rights. These include scaling back commitments to universal access to family planning, removing comprehensive sexuality education from school curricula, promoting childbearing as a civic duty and reinforcing harmful gender stereotypes. Evidence shows that such measures are unlikely to reverse demographic trends, and may instead erode individual autonomy and women’s empowerment.
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