Demographic experts certainly agree with the basic argument that population aging will have significant economic and social consequences. Human societies have had little experience addressing aging populations, and governments have so far proven largely unsuccessful at spurring higher fertility levels. However, the claim that aging will create social and economic implosion across most of the developed world crosses the line into pure speculation. Population aging is not a shock or a catastrophe; it occurs over a period of decades, allowing governments to plan and develop appropriate policy responses. While some protests over reductions in entitlement benefits such as pensions are likely, the repercussions of aging may not be entirely negative. Older adults in developed countries, whose life expectancies have lengthened, may be economically productive into their sixties and beyond, rather than simply decimating national health care budgets. In addition, governments may adjust to aging by modifying their labor force and outsourcing work to the developing world, where the need for jobs is plentiful.

Although no one can predict the future, we can accurately describe the present. Yet alarmists often present a skewed picture of current population trends and minimize the world’s demographic divide. The world still gains 78 million people per year, and 57 percent of the world’s people live in countries with growing populations. More than 95 percent of population growth through mid-century is projected to occur in the developing world. The huge challenge of addressing developing-country population growth by providing sufficient educational and employment opportunities despite high poverty rates is likely to be much more difficult to resolve than the challenge of population aging faced by wealthy developed countries with a high degree of human capital.

Motivated by such complex factors as access to basic health services, the social status and education levels of women, and migration patterns, demographic trends are far from static. Many countries have witnessed dramatic progress through the demographic transition—the shift from high mortality and fertility rates to longer lives and smaller family size—and these countries are now generally the most peaceful, the most democratic, and the wealthiest on the planet. The sustained declines in fertility that these countries have experienced are largely due to the availability of voluntary, rights-based family planning and reproductive health care. The impact of these programs is visible in the lower fertility rates of countries as diverse as Mexico, Indonesia, Iran, the Philippines, and Tunisia. In contrast, countries with extremely young populations—including many in the Middle East and sub-Saharan Africa—face a significantly higher risk of civil conflict than countries with more balanced age structures. Senior intelligence officials such as CIA Director Michael Hayden have recently highlighted population’s key role in security and development.

Howe and Jackson conclude by citing Abraham Lincoln’s description of the United States as “the world’s last best hope”—in this case, because its relatively constant population may leave it as the only stable democracy while the rest of the world faces demography-induced mayhem. Although this vision may be overstated, U.S. leadership is indeed critical to moving global demographic trends in a positive direction. Even as the policy debate surrounding population aging continues, the United States must remain a staunch supporter of development assistance programs, including family planning and reproductive health, for countries on the other side of the demographic divide.

Elizabeth Leahy is a research associate at Population Action International (PAI). She is the primary author of the 2007 PAI report The Shape of Things to Come: Why Age Structure Matters to a Safer, More Equitable World.

• An energy strategy that transitions to a less oil-dependent energy supply;
• A climate policy that recognizes one of the greatest threats to our well-being;
• A renewed emphasis on agriculture so that food production increases, particularly in poor countries;
• A health policy that deals with major health threats, old and new, and equips the world to deal with the next pandemic;
• An international effort to deal with failing states and internal conflicts; and
• A major emphasis on ending poverty.

In all of these areas, development promotion provides an important set of tools. No matter how good our intentions, we cannot accomplish these goals without competent partners: states with the capacity to manage their own affairs and cooperate on global problems—states in which rights and freedoms are guaranteed, and in which people feel they have a voice in the policies that affect them. International development is critical to helping foster such states.

I have two additional comments on From Poverty to Power. First, I think the section on aid could have been stronger. The aid “business” is in considerable disrepair, with simply too many donors trying to do too many things in too many places with too little coordination. There are many ways to make aid more effective, but they will not be easy to implement, and Green could have delved into the complexities a bit more.

Second, the book’s strength is also its weakness. It is nearly 500 pages long and has 792 endnotes! Fortunately, there are summaries in English, French, Spanish, and Portuguese available online—but there needs to be a version aimed specifically at policymakers. Imagine you had 10 minutes to brief President-Elect Obama on the key findings of the book. What would you tell him? For better or worse, in this town, your insights are only as good as your elevator speech.

John W. Sewell is a senior scholar at the Woodrow Wilson Center and the former president of the Overseas Development Council.