Some Highly Developed Countries See Increased Fertility
Monday, August 10, 2009
For decades, the rate at which women were having babies in many of the world's most highly developed countries slowly declined.
While the trend cheered some environmentalists worried about overpopulation, it stoked increasing concern among policymakers, demographers and social scientists about the long-term impact on societies as their populations aged and sometimes began to shrink.
Now, however, new research has produced the first glimmer of hope that economic prosperity may not be linked to an inexorable decline in fertility. The new analysis has found that in many countries, once a nation achieves an especially high level of development, women appear to start having more babies again.
"This is something like a light at the end of the tunnel for some of these countries whose populations were on the path to decline," said Hans-Peter Kohler, a professor of sociology at the University of Pennsylvania who helped conduct the research. "We project a more optimistic future where fertility will go up, which reduces fears of rapid population decline and rapid aging."
Other researchers praised the new analysis as a milestone with potentially far-reaching political and social implications.
"This is very significant," said Shripad Tuljapurkar, a biology and population studies professor at Stanford University, who wrote a commentary accompanying the new research in the scientific journal Nature. "This debate has been going on for some time about these amazingly low fertility rates in some of these countries. It's been a classic policy quandary that people tend to sit around and shake their heads and worry about."
The concern has focused on a nation's "fertility rate," which is generally considered desirable by demographers and sociologists when it hovers around the "replacement rate" -- when the average number of babies born to each woman is about two. That means a country is producing enough young people to replace and support aging workers without population growth being so high that it taxes national resources.
Throughout the 20th century, the fertility rate has generally fallen as economic prosperity has risen, sometimes far below the replacement rate in some of the world's most highly developed nations, such as Japan, South Korea, Germany, Spain and Italy.
"There was a consensus that as countries develop, become richer and provide more education, that fertility would know only one trend -- and that trend was downward," Kohler said. "This raises a broad range of concerns. Systems such as pension systems would not be sustainable. A rapid decline in the labor force could result in an economic decline and a loss of competitiveness and perhaps a loss of innovation."
Resistant to the notion of replenishing their populations through immigration, some countries, such as Sweden and Italy, have become so concerned about their stubbornly low fertility rates that they have tried offering women financial incentives to have more babies, without significant success.
To explore whether economic development is necessarily linked to falling fertility, Kohler and his colleagues examined fertility trends between 1975 and 2005 in 37 of the most developed countries. They used a measure developed by the United Nations known as the human development index (HDI), which combines income data with other measures of advancement, such as longevity and education levels.
Fertility rates did tend to decline as a nation's HDI rose, the analysis showed. But for 18 of 26 countries that crossed a certain threshold of development -- an HDI of at least .9 -- their fertility rates began to rise again.