Geography
Demographic Transition Theory and Population Aging in Post-Industrial Nations
Quick fact
Japan's fertility rate fell to about 1.3 births per woman, far below the replacement level of 2.1, and its median age now exceeds 48 years—one of the highest in the world.
Why this is interesting
You might have heard that Japan and Italy have 'too many old people'—but how did they get there? The answer lies in a powerful pattern called demographic transition.