The New York Times reports:

The world’s demographics have already been transformed. Europe is shrinking. China is shrinking, with India, a much younger country, overtaking it this year as the world’s most populous nation.

But what we’ve seen so far is just the beginning.

The projections are reliable, and stark: By 2050, people age 65 and older will make up nearly 40 percent of the population in some parts of East Asia and Europe. That’s almost twice the share of older adults in Florida, America’s retirement capital. Extraordinary numbers of retirees will be dependent on a shrinking number of working-age people to support them.

In all of recorded history, no country has ever been as old as these nations are expected to get.

As a result, experts predict, things many wealthier countries take for granted — like pensions, retirement ages and strict immigration policies — will need overhauls to be sustainable. And today’s wealthier countries will almost inevitably make up a smaller share of global G.D.P., economists say.

This is a sea change for Europe, the United States, China and other top economies, which have had some of the most working-age people in the world, adjusted for their populations. Their large work forces have helped to drive their economic growth.

Those countries are already aging off the list. Soon, the best-balanced work forces will mostly be in South and Southeast Asia, Africa and the Middle East, according to U.N. projections. The shift could reshape economic growth and geopolitical power balances, experts say. [Continue reading…]