Between now and 2030, every country will experience population ageing—a trend that is both pronounced and historically unprecedented. Over the past six decades, countries of the world had experienced only a slight increase in the share of people aged 60 years and older, from 8% to 10%. But in the next four decades, this group is expected to rise to 22% of the total population—a jump from 800 million to 2 billion people. Evidence suggests that cohorts entering older age now are healthier than previous ones.