The Graying Planet

The world's populations are aging rapidly, triggering demographic changes that will have a profound impact on economies, government expenditures and international migration patterns. In the past century, life expectancy has doubled, while the average family size has shrunk. By 2050, the number of children under 5 is expected to drop by 49 million, while the number of adults over 60 will skyrocket — by 1.2 billion. An unprecedented number of senior citizens will be depending on diminishing numbers of younger workers to contribute to pension and health care programs for the elderly. And it's not just a problem for wealthy countries: Developing countries' elderly populations are growing faster than in the developed world. For example, in 20 years, China will have 167 million senior citizens — more than half the current U.S. population. On the positive side, some demographers believe aging societies will be more peaceful, since seniors suffer fewer crime and drug-abuse problems. And with fewer children, there could be more money per capita for their education.