The year 2018 marked an epochal demographic turning point: Earth became home to more people aged 65 years and over than children under five, for the first time ever.
In this newly grey world, rich countries are generally richest in senior citizenry — but this won’t last. In recent decades the fertility rate has typically also fallen in developing countries, and at increasingly lower per capita incomes. Life expectancy has been increasing similarly.
Middle-income developing countries — including G20 members Argentina, Brazil, China, Russia and Turkey — are closing in on the rich world’s senior citizen population share. Thailand, Tunisia and Sri Lanka are among dozens more that will join them in future decades as the silver tsunami spreads.