"There are 1.2 billion people between the ages of 15 and 24 in the world today — and that means that many countries have populations younger than ever before. Some believe that this 'youth bulge' helps fuel social unrest — particularly when combined with high levels of youth unemployment. Youth unemployment is a 'global time bomb,' as long as today’s millennials remain 'hampered by weak economies, discrimination, and inequality of opportunity.' The world’s 15 youngest countries are all in Africa. Of the continent’s 200 million young people, about 75 million are unemployed.
On the flip side, an aging population presents a different set of problems: Japan and Germany are tied for the world’s oldest countries, with median ages of 46.1. Germany’s declining birth rate might mean that its population will decrease by 19 percent, shrinking to 66 million by 2060. An aging population has a huge economic impact: in Germany, it has meant a labor shortage, leaving jobs unfilled."
Via Seth Dixon, Bonnie Bracey Sutton, Jim Lerman