He not busy being born is busy dying*

* Bob Dylan

Shrinking Societies: The Other Population Crisis

The earth's population is growing at an alarming rate, but in some countries the lack of growth is the biggest problem.

The world population is expected to expand by 37 percent to 9.5 billion in 2050, according to the report, but growth will not be evenly distributed. Developing countries will grow the most, with the population in Africa expected to double.

Japan is expected to see its population contract by one-fourth to 95.2 million by 2050, according to the Population Reference Bureau, a Washington-based research group, making it the fastest-shrinking country in the world. Former Eastern Bloc nations Ukraine and Georgia came in second and third, respectively, in a ranking of more than 200 countries by Businessweek.com based on the Population Reference Bureau's 2010 World Population Data Sheet.

"Europe, Korea, and Japan have gone into panic mode," says Carl Haub, a senior demographer at the Population Reference Bureau. A declining population impacts a country's economic growth, labor market, pensions, taxation, health care, and housing, according to the U.N. Globally by 2050, the number of older persons in the world will exceed the number of young for the first time in history, according to the U.N. The imbalance will create havoc in the pension systems and make it difficult to support retired and elderly persons, Haub says.

As fewer children are born, the fastest-growing age group in the world is people age 80 and older, according to the U.N. In 2000, there were about 4 people over age 85 for every 100 people ages 50 to 64; by 2050, it will rise to 11.

The situation is more dire in places such as Japan, where the Population Reference Bureau predicts there will only be one working-age person for every person over age 65 in 2050.

Click here to see the 25 countries with the fastest-shrinking populations.

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