The population challenge

By Bjorn Lomborg

BRISBANE ― When people think of the world's "population problem," they often focus on rapid demographic growth in parts of the developing world. But, globally, the population-growth rate is actually falling, and is expected to plateau later this century. Though we cannot afford to ignore the fact that, according to United Nations estimates, there will be 2.4 billion more mouths to feed worldwide by mid-century, another population problem also merits serious attention: large pockets of demographic decline.

In developed countries, not only is the share of elderly people rising; birth rates are too low to maintain the size of the total population. While the life expectancy gains that are driving this shift should be celebrated, their problematic consequences ― forcing a declining number of working-age people to support an increasing number of retired people ― must be addressed.

Meanwhile, in developing countries, the opposite is happening, with too many young people lacking employment ― or, at least, high-quality, full-time employment. To be sure, it will not be very long before these countries begin to confront the problems of aging and shrinking populations, as well. But, for now, they have plenty of working-age citizens ― and they need jobs.

In fact, these contrasting trends present an ideal opportunity for global demographic rebalancing. By easing restrictions on migration, developed countries could bolster their dwindling workforces with young people from developing countries. These migrant workers' taxes would help developed countries fund services for the elderly, and their remittances would help their home countries.

This approach has enormous potential benefits. Indeed, a modest 3 percent increase in the developed-country workforce would provide a larger economic boost than removing all remaining trade barriers. Moreover, every dollar invested in this initiative would produce nearly $50 in returns, making it an exceptionally effective use of limited resources.

These impressive figures emerged from a comprehensive analysis conducted by a team of top economists tasked by my think tank, the Copenhagen Consensus Center, with assessing possible population-related targets, in order to identify the best global investments. (Additional teams considered issues in 18 other areas.)

Such objective, empirically-based analysis should guide ongoing efforts ― involving the U.N., national governments, NGOs, and other actors ― to establish the next global development agenda, which will be launched next year. Indeed, it is the only way to ensure that the poorest people get the best deal, and that governments get the biggest bang for their buck. While the current agenda ― centered on the so-called Millennium Development Goals ― has produced significant successes, its failure to emphasize such cost-benefit analyses has prevented practitioners from fully optimizing limited resources.

Another advantage to this kind of analysis is that it can highlight future risks associated with longer-term trends like global population growth. This is important, as a rising population may be an even bigger problem than was previously thought. A new study argues that there is now a 70 percent chance that the world population will not peak this century, and an 80 percent chance that it will reach 9.6-12.3 billion people by 2100. Sub-Saharan Africa ― persistently the poorest region ― will be the main engine of demographic growth.

Fortunately, there is a cost-effective way to slow down this engine: improve women's access to modern contraception. Providing contraception for the 215 million women worldwide ― a large share of them in Africa ― who would like to avoid pregnancy would cost about $3.6 billion annually.

This is a pittance, when one considers the massive payoff. Each year, there would be an estimated 640,000 fewer newborn deaths, 150,000 fewer maternal deaths, and 600,000 fewer children losing their mothers ― yielding economic benefits of roughly $145 billion.

And there is more good news. Better access to contraception would enable mothers to spend more time raising ― and educating ― the children that they do have. Fewer kids also mean that a larger share of the population would be working, boosting the economy by an estimated $288 billion annually for a generation. Altogether, each dollar spent on family-planning programs yields a whopping $120 in benefits.

Of course, simply distributing contraception would not be enough. People in poor countries ― especially in high-fertility African countries, which have only 18 percent of the world's population but produce 38 percent of its newborns ― would also benefit considerably from educational initiatives centered on health and family planning.

There is no silver bullet for sustainable development. Improving the lot of the world's poorest people as much as possible means navigating powerful forces, entrenched habits, and, most important, severe financial, temporal, and human-capital constraints. For that reason, objective, data-driven analysis is the best guide.

Bjorn Lomborg, an adjunct professor at the Copenhagen Business School, founded and directs the Copenhagen Consensus Center. He is the author of "The Skeptical Environmentalist and Cool It.'' For more stories, visit Project Syndicate (www.project-syndicate.org).