Phillip Longman is a senior fellow at the New America Foundation, where he studies health care policy and demography. A former editor at U. S. News & World Report, Longman is the winner of UCLA's Gerald Loeb Award, the top prize for investigative journalism from Investigative Reporters and Editors. His 2004 book The Empty Cradle (Basic Books) explores the impact of declining fertility rates on the social, economic, and political health of societies across the globe.

Since the 1960s, many in the West have been deeply concerned about the social and environmental consequences of population growth—witness, for instance, the popularity of Paul Ehrlich's The Population Bomb. In the United States, our population recently passed the 300-million mark. Should we in the West still be concerned about population growth at home and abroad?

World population is still increasing by some 77 million annually. That's equivalent to adding a whole new country the size of Egypt every year. Yet here is a curious fact few people know: the number of children under 5 in the world is actually smaller than in 1990.

How can this be? Mostly it is because of the massive global decline in birthrates. Now, in literally every region outside of sub-Saharan Africa, the average woman no longer bears enough children to replace the population. For now, world population continues to grow, though at a slower and slower rate, primarily because of the enormous increase in the numbers of elderly people. But many countries, such as Russia and Japan, are already shrinking in absolute size, and on current trends, global depopulation will occur within the lifetime of today's young adults.

Why should we be worried about falling birthrates in Europe and the United States? What are the social, economic, and political implications of this demographic phenomenon for the West?

For nations, as for people, there are many benefits to not having children, at least until you grow old. Many economists believe, for example, that falling birth rates helped make possible the economic boom that occurred first in Japan and then in many other Asian nations, beginning in the 1960s. As the relative number of children declined, so did the burden of their dependency, leaving more resources available for adults to invest and enjoy.

But over time, a falling birthrate means not just fewer children but also fewer workers, even as the population of dependent elders increases. That's the bind that grips more and more of the world today. There are fewer and fewer working-aged people to support each elder. This is true within the formal systems we use to provide support in old age, such as Social Security, Medicare, and private pension plans. And it is also true within the family. When you grow up with few or no siblings, as is now becoming the norm throughout much of the world, there is often no one else available to share in the burden of looking after one's ailing parents.

Ultimately, low fertility means population aging and population decline. This is not all bad. A population dominated by middle-aged and elderly people, for example, is probably less inclined to send its few children off to war. But our economy, particularly large sectors like housing and transportation, has always depended on population growth to sustain economic growth. Similarly, the government programs we use to create security in old age, like Social Security as currently structured, depend on an ever increasing supply of youth.

At best, all the major institutions of our society will have to be fundamentally reformed to deal with a world in which each new generation is smaller than the last. Refusing to face up to this means rising poverty, increased taxes, depleted savings, lower investment, and a very real risk that excessive government borrowing and pension debt will tank the world economy. All this could happen much sooner than most people realize. Today, for example, the United States has a fairly healthy birthrate compared to the rest of the industrialized world, but it has grown dependent on massive borrowing from rapidly aging nations. Germany, Japan, and China are growing so old that they will soon be drawing down their savings and repatriating their investments in U.S. debt. This implies a complete restructuring of the world economy—one that could well entail a prolonged global recession or depression.

You are a senior fellow at the New America Foundation, a progressive think tank. Why should progressives be concerned about fertility declines in the West? How do fertility declines specifically threaten progressive values and public policies?

It's fair to say that most self-described "progressives" don't agree with me that low fertility is a problem. Many environmentalists, for example, believe that fewer people means a cleaner environment. Other progressives suppose that a decline in population would increase the amount of food and other resources available to the poor. Many feminists, gays, and "childless by choice" people in general feel threatened by suggestions that society needs more children. And when it's pointed out that the lowest birthrates are generally found among the most "progressive" people, then the conversation gets really heated.

On all these counts, I believe progressives are in denial. Today in the United States, for example, we have far cleaner air and water than we did in the 1940s, when the population was just half its current size. That's no paradox. Population growth is a spur to more efficient and cleaner use of resources, so our cities are no longer choked with smoke from steam engines and our cars get far better mileage and are far less polluting. Similarly, population growth is what drove us as a society to find far more productive ways to grow food. Thanks to increased crop yields, per capita food production is higher than ever, even as world population surpasses 6 billion. At the same time, there is more forested land in the United States than in the 19th century because so much less acreage is needed for farmland.

Progressives also tend to forget that many of their positions on human reproduction, such as a "woman's right to choose," only won widespread support when fears of overpopulation began to pervade the culture in the 1960s and '70s. Until then, bans on abortion, birth control, and homosexuality, for example, were justified in many people's minds by fears of underpopulation, which left questions of human reproduction too important to be settled by individual "choice." They also forget that if progressives themselves "forget to have children" then the future belongs to people who have opposing values. Finally, progressives forget that without a growing population, such "crown jewels" of the welfare state as Social Security lose their financial sustainability.

How might dramatic population declines in Europe, and the severe economic and political challenges they pose to countries like Germany, which may soon see its pension system collapse under the weight of its own demographic decline, affect élite thinking about the family? Many scholars, public policy analysts, and journalists I'm familiar with tend to assume that the family is simply destined to grow ever weaker. Might dramatic demographic developments change élite thinking about the family? Might such developments also change the kinds of family-related public policies Western élites support?

During the 19th and especially the 20th century, the state gradually took over many of the functions once performed by the family—notably education and support in old age. Élites have generally cheered this process on. But more and more in the future, individuals will find that they cannot rely on the élites who govern them. They will see health and pension benefits cut, even as taxes rise. They will see funding for education squeezed by the ever growing burden of providing even minimal benefits to the dependent elderly. This implies that more and more people will be forced to rely again on the traditional, extended family. People will need to have children and raise them well if they hope to find security in old age. For the same reason, they will also have to sacrifice on behalf of their aging parents so that their own children grow up to see this as a moral duty.

Today, élites who are uncomfortable with this future are calling for the state to take over still more responsibilities from the family—for example, by offering subsidies for child care, greater family allowances, or even bonuses to parents, all of which are being tried in Europe and much of Asia. I'm not opposed to such measures on ideological grounds, but I'm doubtful about their potential to boost the birthrate for more than a short time unless very serious amounts of money are involved, and that creates huge political problems.

If you are going to pay people to have children, you're going to spend a lot on people who would have had them anyway. And meanwhile, people who currently see no reason to become parents are not going to be persuaded by the offer of even tens of thousands of dollars in benefits. In the United States, the direct cost of raising a middle-class child born this year through age 18, according to government estimates, exceeds $200,000—not including college. Meanwhile, in an age in which most women have the opportunity to join the paid workforce, the cost of motherhood—in lost wages and compromised careers—is often measured in the millions.

The huge bundle of benefits World War II veterans received under the G.I. Bill does seem to have contributed to that era's baby boom. But in those days, we didn't have to pay for Medicare, and Social Security was only a tiny percentage of federal spending. The median age of voters was also much lower then than now, and the feminist and environmental movements were still in the future. For all these reasons, I think élites are going to have a hard time selling pronatalism on a scale that's sufficient to the problem. In the end, I see élites simply losing their legitimacy because they cannot maintain, much less expand the welfare state in an aging society.

If the demographic predictions you make in The Empty Cradle come to pass, how might they affect the relative position of orthodox religions in the West? In other words, what role might Islam, evangelical Protestantism, or traditional Catholicism play in Western countries that have experienced subreplacement fertility for 40 to 50 years? How might their distinctive approaches to family life look to ordinary people? To élites?

On current trends, Europe's population just withers away. But I don't expect current trends to continue indefinitely in Europe or the West in general, for a special reason.

In Asian countries such as Japan, nearly everyone eventually marries and eventually has, almost without exception, one child. In Europe, and the West in general, by contrast, there is far more diversity in reproductive behavior. Among American baby boomers, for example, nearly a fifth of us never had children, and another 17 percent had only one.

The high incidence of childless and single-child families in the West has one big implication many overlook. It means a very large proportion of the children that are being born are being produced by a small subset of the current population. And who are the people who are still having large families today?

The stereotypical answer is poor people, or dumb people, or members of minority groups. But birth rates among American racial and ethnic minority groups are plummeting. The more accurate answer is deeply religious people.

To be sure, religious fundamentalists of all varieties are themselves having fewer children than in the past. But whether they be Mormons, Orthodox Jews, or Islamic or Christian fundamentalists, devout member of these Abrahamic religions have on average far larger families than do the secular elements within their society.

In Europe, for example, the fertility differential between believers and nonbelievers has recently been estimated at 15-20 percent. Though children born into religious families often do not become religious themselves, many do, especially if they themselves go on to have children. Meanwhile, of course, the childless stand no chance of passing along their values to their progeny.

The faithful thus begin to inherit society by default. The West's total population may fall or stagnate, perhaps for quite awhile; but those who remain will be disproportionately committed to God and family, whether they be Christians, Muslims, Jews, or members of new pro-natal faiths. Let us just hope that this new age of faith will also be an age of peace.

W. Bradford Wilcox, an assistant professor of sociology at the University of Virginia and a fellow at the Witherspoon Institute, is the author of Soft Patriarchs, New Men: How Christianity Shapes Fathers and Husbands (Univ. of Chicago Press).

Copyright © 2007 by the author or Christianity Today/Books & Culture magazine.
Click here for reprint information on Books & Culture.