The world is undergoing extensive demographic changes that are slowing economic growth and raising public debt, increasing the risk of medium-term financial instability and conflict over resource distribution in many advanced economies while increasing political and economic instability in many low-income developing economies. Differing demographic developments around the world are giving rise to economic and political challenges. High-income (advanced) economies have been characterized by very slow population growth, stagnating population levels or even outright population decline, with Japan experiencing its first decline in population levels in 2011. This has led to a significant increase in the share of the elderly population and, in some cases, a decline in the working-age population in absolute terms. Meanwhile, upper-middle-income countries are undergoing very similar demographic changes, although they trail advanced economies by a decade or two. However, their demographic transitions frequently have been faster, largely due to rapid declines in fertility rates, which...
