Population and Society

In 2006, the latest year with data available, the world's child mortality rate-the number of children who die before the age of five per 1,000 live births-dropped to 72, a 20-percent decline since 1990, when 93 children died for every 1,000 live births.¹ (See Figure 1.) For the first time since recordkeeping began in 1960, child mortality fell below 10 million, to 9.7 million, which was less than half the number who died before reaching five in 1960.² This welcome achievement, however, still leaves most devel­oping countries well short of the pace needed to meet the United Nations Millennium Development Goal (MDG) of reducing under-five child mortality by two thirds between 1990 and 2015. And despite the steady decline in global under-five deaths, disparities between and within regions continue to grow.

Under-five mortality decreases as per capita income increases.³ In the poorest households in developing countries, 107 children under the age of five die for every 1,000 live births.⁴ This is nearly 40 percent higher than in the richest households in those nations, where the rate is 67 deaths for every 1,000 live births.⁵ The disparity is even greater when compared with the rate in industrial nations-6 deaths per 1,000 live births.⁶

For the average child living in rural areas and isolated from basic health services and adequate sanitation, the under-five mortality rate is 105-far greater than in urban areas, where the rate is 69 deaths per 1,000 live births.⁷

East Asia and the Pacific, Central and Eastern Europe, and Latin America and the Caribbean have reduced child mortality rates by half since 1990.⁸ (See Figure 2.) They are the only regions on track to meet the child mortality MDG.⁹ In 2006, the mortality rate for each of these regions was below 30 per 1,000 live births.¹⁰

A number of countries in Latin America, such as Cuba and Chile, have lowered their child mortality rates by more than 50 percent since 1990 and are more than halfway to cutting them by two thirds.¹¹ Despite these positive trends, the averages mask wide disparities between and within Latin America.¹² The mortality rates of Haiti and Bolivia are more than twice the regional average, and indigenous children living in both urban and rural areas in Latin America face a greater risk of dying before their first birthday than non-indigenous children.¹³

South Asia has shown improvement, reducing its under-five mortality rate from 123 child deaths per 1,000 live births in 1990 to 83 in 2006.¹⁴ Even with the improvements, how­ever, in 2006 this region had the second highest number of deaths among children under the age of five-roughly 3.1 million-accounting for 32 percent of the global total.¹⁵

Afghanistan, Pakistan, and India account for half the world's undernourished children, des­pite having just 29 percent of the developing world's under-five population.¹⁶ Afghanistan's child mortality rate was 252 for the 2002-05 period, three times South Asia's average rate and the third highest in the world.¹⁷ Compared with the regional average of 1 child death for every 12 children, in Afghani­stan 1 child dies for every 5 children.¹⁸

Sub-Saharan Africa has made the least pro­gress in reducing child mortality rates, with 1 in every 6 children dying before the age of five.¹⁹ On average, its under-five mortality rate was 160 deaths for every 1,000 live births in 2006, an improvement from its 1990 rate of 187.²⁰ Some countries in West and Central Africa, however, have made no progress, and some nations actually reported increases in under-five mortality rates, such as Côte d'Ivoire.²¹ Only 22 percent of the world's children are born in sub-Saharan Africa, yet this region accounts for 49 percent of the world's under-five deaths.²²

Lack of safe water and sanitation along with inadequate hygiene are largely responsible for breeding the leading killers of children under five: diarrheal diseases, pneumonia, neonatal disorders, and undernutrition.²³ Some 88 per­cent of diarrheal diseases, the second most ­common direct cause of under-five deaths, are attributed to poor water management.²⁴ These illnesses take nearly 2 million children a year and account for 17 percent of children deaths.²⁵

Access to adequate health care is also a leading contributor. Pneumonia, the single leading cause of child mortality, kills 2 million children and 1 million infants worldwide each year, accounting for 19 percent of children's deaths and nearly a quarter of neonatal deaths.²⁶ Sadly, only 56 percent of the world's children with pneumonia are taken to appropriate health care providers.²⁷

Life is most vulnerable in the first 28 days of life, when most of the world's child deaths occur, taking 4 million infants each year.²⁸ Collectively, neonatal causes contribute to 37 percent of under-five deaths. The disparity between neonatal deaths in rich and poor nations has been growing.²⁹ Newborns in developing countries are eight times more likely than newborns in industrial countries to die, largely because mothers there receive inadequate or no care during pregnancy, childbirth, and the postpar­tum period.³⁰ The World Health Organization reports that nearly three quarters of all neonatal deaths could be prevented if women were adequately nourished and received appropriate care.³¹ Skilled help at birth can prevent the leading causes of newborn deaths-severe infections and asphyxia, which together account for 49 percent of neonatal deaths.³²

Undernutrition, the result of insufficient food intake and repeated infectious diseases, decreases a child's resistance to infection and is the underlying cause in up to half of all under-five deaths.³³ With 42 percent of South Asia's under-five population underweight, the region has the highest rate of undernutrition world­wide.³⁴ Maternal undernutrition is also a significant contributing factor to child mortality, leading to children who are severely underweight with stunted physical and intellectual growth.³⁵

The low status of women presents serious challenges in reducing child mortality, especi­ally in South Asia and sub-Saharan Africa. In India, for example, girls are up to 50 percent more likely than boys to die between their first and fifth birthdays.³⁶ Exclusion of girls from health care is often most severe in rural areas and in urban slums, where women are largely illiterate and suffer from sociocultural barriers to services, compromising the health of all family members.³⁷ Poverty, race, language, and culture are other factors excluding women and their children from public health services.³⁸

Armed conflicts and AIDS also affect a young child's prospects for survival. More than half of the 11 countries where 20 percent or more of children die before age five suffered a major armed conflict since 1989.³⁹ In the war-torn Democratic Republic of Congo, for example, the child mortality rate was 211 per 1,000 live births in 2000-05.⁴⁰ AIDS has also destabilized sub-Saharan Africa, leaving 12 million children without parents.⁴¹ A motherless child is more likely than an infant with a surviving mother to die before reaching age two.⁴² And the children themselves are dying of AIDS: sub-Saharan Africa accounts for almost 90 percent of pedi­atric HIV infections.⁴³

The MDG campaign has encouraged basic health interventions, such as early and exclusive breastfeeding, measles immunization, and Vitamin A supplementation, which have decreased child mortality rates.⁴⁴ In Latin America, timely measles immunization since 2000 has reached 93 percent of the region's population, nearly eliminating this disease that still kills at least 1 million people a year, 80 percent of whom are children under the age of five.⁴⁵

If the MDG is to be reached, annual child mortality must be reduced to fewer than 5 million by 2015.⁴⁶ Achieving this will rely heavily on accomplishing the other important Millen­nium Development Goals: reducing poverty and hunger, improving maternal health, increasing the use of cleaner water and sanitation, and providing affordable essential drugs on a sus­tainable basis.

Although the average woman worldwide is giving birth to fewer children than ever before (see Figure 1), an estimated 136 million babies were born in 2007.¹ Global data do not allow demographers to be certain that any specific year sets a record for births, but this one cer­tainly came close. The year's cohort of babies propelled global population to an estimated 6.7 billion by the end of 2007. (See Figure 2.)

The seeming contradiction between smaller-than-ever families and near-record births is easily explained. The number of women of childbearing age keeps growing and global life expectancy at birth continues to rise. These two trends explain why population continues growing despite declines in family size. There were 1.7 billion women aged 15 to 49 in late 2007, compared with 856 million in 1970. The average human being born today can expect to live 67 years, a full decade longer than the average newborn could expect in 1970.

Only the future growth of the reproductive-age population is readily predictable, however: all but the youngest of the women who will be in this age group in two decades are already alive today. But sustaining further declines in childbearing and increases in life expectancy will require continued efforts by governments to improve access to good health care, and both trends could be threatened by environmental or social deterioration. The uncertain future of these factors makes population growth harder to predict than most people realize.

Diversity in fertility rates (the average number of children born to each woman) and life expectancy (the years that the average baby born today can be expected to live) marks the world's population in the early twenty-first century. Women typically bear five or six children in parts of sub-Saharan Africa and western Asia, while women have fewer than two in most industrial countries and some developing ones, such as Cuba, Sri Lanka, Thailand, and Tunisia.

Fertility rates that were consistently below two children per woman would eventually lead to a shrinkage of national populations in the absence of counterbalancing immigration. It can take decades for low fertility to halt growth, however, in populations with large proportions of young people due to high fertility in the past.

Life expectancy worldwide varies from a high of 83 years in Japan to a low of 40 years in Swaziland, the country with the highest prevalence of HIV infection. Worldwide, deaths from AIDS totaled approximately 2.1 million in 2007, and even more people—some 2.5 million—are estimated to have been newly infected with HIV that year.² One bright sign is that in 2007 the Joint United Nations Programme on HIV/AIDS and the World Health Organization lowered their estimates of HIV infections worldwide, from approximately 39 million to 33 million.³ But this represented a statistical adjustment, not a downward trend in infections.

Due to both the unprecedented number of people alive and the ease of travel, the global movement of people has continued on the largest scale in history. Data are insufficient, however, to be confident about trends from one year to the next. The United Nations estimated that in 2005 nearly 200 million people lived outside their country of birth, a "nation" of international migrants as large as Brazil—and twice as many people as were in that category in 1980.⁴

U.N. demographers believe that the numbers of people moving to other countries to work and live is rising, propelled by increases in undocumented international migration and in refugees returning to their home countries.⁵ Many more people move within countries. By the end of 2008, half of the world is expected for the first time in human history to live in such urban areas—though since the definition of "urban" varies by country, there is no way to be certain when this moment of global rural-urban equilibrium actually occurs.⁶

The United States adds to global demo­graphic diversity by having by far the largest population in the industrial world (about 303 million) and average fertility above two child­ren per woman, the highest among industrial countries.7 In 2006, U.S. fertility rose to its highest rate since 1971—2.1 children per woman.⁸ Among the reasons for the jump may be decreasing access to abortion and greater proportions of young people lacking easy and affordable access to sexuality education and contraception. Although this level of fertility could eventually stabilize an industrial country's population if there were no net immigration, in the United States the proportions not only of immigrants but of young women of childbear­ing age are both so high that no such outcome is imminent.

Among the most direct influences on fertility is access to and use of contraception. More than 700 million women, half of those aged 15 to 49 in developing countries, are at risk of unin­tended pregnancy, due to either improper use of contraception or—for an estimated 137 million women—no use of contraception at all.⁹ At the same time, spending on family planning by governments worldwide has been stagnant in recent years—and has remained at a fraction of what governments agreed is needed to assure all women and couples access to services and contraceptives.¹⁰

A trend that may be more hopeful for the future of world population is the gradual improvement worldwide of women's health and their economic, educational, and political status relative to men. For the past two years the World Economic Forum (WEF) has assembled a global index of the closing of this gender gap. The 2007 index showed slight improvements over 2006 in every category except health.¹¹ A comparison of the percent of the overall gender gap that had closed and the fertility rates of 128 countries indicated a clear correlation between high female status and low fertility.¹² (See Figure 3.) The new WEF index could provide a dataset worth watching in the years ahead, and—if the gender gap continues narrowing—could point the way toward a more environ­mentally sustainable and socially equal human pop­ulation in the years ahead.

In 2000–04, the portion of adults in the world with reading and writing skills reached 82 percent, up from 75 percent in 1990.1 (See Table 1.) The net enrollment ratio of children of eligible age entering primary school was 87 percent, up from 81 percent in 1991.2 Although data are unavailable for several countries in conflict or post-conflict situations, these trends indicate progress toward international goals set in 2000 of meeting the basic learning needs of people of all ages within a generation.3

Although the illiterate population has dropped from its 1990 level of 874 million, there are still 781 million people over the age of 14—or one in five adults—who lack basic literacy skills.4 Some 98 percent of illiterate people live in the developing world.5 The region with the lowest literacy rate is Africa, at 62.5 percent, but Asia has the largest illiterate population—some 546 million people.6 In the poorest countries, only about half of all adults can pass basic literacy tests.7

Some developing countries have been making significant increases in adult literacy, however. Egypt’s literacy rate jumped from just 47.1 percent in 1990 to 71.4 percent in 2000–04, while Ethiopia saw a 16.6-percent increase in the literacy rate and China registered a 52-percent drop in the absolute number of illiterates in the same period.8

The three regions furthest from universal primary education saw improvements in enrollment: the Arab States, for example, saw a 6-percent increase from 1999 to 2004.9 In South and West Asia, enrollment during those five years grew by 19 percent, and in sub-Saharan Africa there was a 27-percent increase.10

Education is a powerful tool against poverty: it is linked to higher income levels.11 And the better educated a person is the more likely he or she is to report being in good health, regardless of income.12 Recent studies even show a positive correlation between life expectancy and the number of years of education a person has.13 For these and other reasons, education is essential to sustainable development.14 Almost two thirds of the people in the world who lack literacy skills are female, and in any region of the world an illiterate adult is most likely to be a woman.15 (See Table 2.) Central and Eastern Europe have the largest share of the illiterate population being female.16 Globally, women appear to be stopping their education at lower and lower levels, a trend that could erode education gains.17

Great strides have been made toward gender parity in primary education, however. Of the 181 countries with 2004 data available, some two thirds have achieved gender parity in primary education.18 And for every 100 boys in primary school, there are 94 girls.19

Efforts focused on women’s education tend to increase female participation and earnings in the labor force and to allow for more effective transfer of the benefits of education—health, educational opportunities, and more—from one generation to the next.20 On average, a child whose mother has no education is twice as likely to not be in school as a child with an educated mother.21

Investment in girls’ education results in some of the greatest returns of all development investments.22 It is linked to higher crop yields and per capita income increases, for instance, and with lower rates of HIV infection and infant mortality.23 In addition, education for girls reduces fertility rates, as educated women are more likely to delay marriage and childbearing, use reliable family planning methods, and have fewer and healthier babies.24

Developing countries have unique challenges to achieving universal education. In sub-Saharan Africa, for example, nearly 10 percent of children under 17 years of age have lost at least one parent to HIV/AIDS, and an orphan is 13 percent less likely to be in school than a nonorphan. 25 Some 80 percent of people with disabilities live in developing countries, and it is estimated that more than one third of out-ofschool children have a disability.26 Poor children are less likely to attend school: the number of children not attending school in the poorest 20 percent of households is more than triple that in the wealthiest 20 percent.27 Child soldiers and other youngsters affected by conflict represent another sector facing acute obstacles to education, as do sexually exploited children and those who are pressured into the labor force.28

While funding for education is on the rise, it is estimated that $11 billion a year in development assistance is required to achieve the goal of Education For All (EFA) agreed to in 2000, which is more than twice the current level of aid for basic education.29 Some countries, including Italy, Nicaragua, Saudi Arabia, and Tunisia, significantly increased the share of their gross domestic product spent on education between 1990 and 1998–2000.30 Others, like Bulgaria, Canada, and Uruguay, reduced the percent allocated to this sector.31

Many developing countries have abolished school fees, leading to a surge in primary school students. After Kenya removed school fees in 2003, 1.2 million additional students entered the school system; in 2005 Burundi enacted the same policy and increased enrollment by 500,000.32

At least 160 countries committed to achieving six EFA goals, which include a special focus on Early Childhood Care and Education (ECCE).33 ECCE, like education for girls, is a particularly cost-efficient means of approaching the goals of EFA.34 Studies suggest ECCE is also exceptionally effective at offsetting disadvantage and inequality for poor and culturally excluded children.35

Enrollment in pre-primary education has nearly tripled since the middle of the 1970s, though coverage remains very low in most of the developing world.36 Most regions now have nearly as many girls as boys enrolled in preprimary education.37

Countries that have made significant progress toward universal education promote policies that allocate public funds to education adequately and equitably and that promote high enrollment, especially for girls.38 Successful countries also have policies that give women the right to own property and the ability to earn an independent income.39 ECCE programs are most effective in promoting Education For All goals when they are taught in the child’s native language, challenge gender stereotypes, mainstream children with disabilities, and are combined with other services such as health care, nutrition, and social services.40

As the mid-point approaches in efforts to meet the U.N. Millennium Development Goals (MDGs) by 2015, progress toward achieving them is uneven. Although many countries have made important strides, greater efforts by both industrial and developing nations are needed to accelerate action.1

World leaders first adopted the MDGs in preliminary form at the U.N. Millennium Assembly in September 2000.2 In addition to eight overarching goals, the MDGs have 18 specific targets, most of which are to be achieved by 2015. These include cutting poverty and hunger rates in half from their 1990 levels, reducing child mortality by two thirds, and halving the proportion of people lacking access to clean drinking water and adequate sanitation. 3 (See Box 1.) The United Nations also developed a set of 48 indicators to monitor progress toward the MDGs.4

Current estimates suggest that the world is on track to meet the overarching income poverty target—to halve by 2015 the proportion of people living on less than $1 per day.5 The share of the developing world’s population living in extreme poverty declined from 27.9 percent in 1990 to 19.4 percent in 2002 (the most recent year for which data are available). 6 This drop was driven in no small measure by particularly rapid progress in poverty reduction in much of Asia. Trends have unfortunately been less encouraging in other regions, particularly in sub-Saharan Africa, where the absolute number of people living in extreme poverty increased by 140 million between 1990 and 2002 due to population growth despite a modest decline in the overall poverty rate.7 If present trends continue, few African countries are expected to meet the 2015 target for income poverty.8

The situation is even bleaker when it comes to hunger. Although the proportion of people suffering from hunger worldwide declined modestly over the last decade, the absolute numbers are rising, with an estimated 834 million chronically undernourished people in developing countries at last count.9

Child mortality trends are somewhat more positive, with 2.1 million fewer deaths among children under five in 2004 than in 1990.10 Still, the U.N. Development Programme estimates that at current rates of progress, the target of reducing by two thirds the child mortality rate by 2015 will be missed by some 4.4 million deaths that year.11

Major challenges also remain in efforts to meet other human development goals, such as those related to gender equity, maternal health, and deadly diseases such as HIV/AIDS, malaria, and tuberculosis. The World Bank reports that all regions are off track on at least some of these goals and that South Asia and sub-Saharan Africa are off target on all of them.12

Nonetheless, there are also some encouraging signs. For example, the number of countries set to meet the goal of providing universal primary education by 2015 has increased signifi- cantly since 2000, and gender gaps in access to primary and secondary education are narrowing. 13 The number of AIDS patients in developing countries with access to treatment has increased rapidly, rising from less than 100,000 in 2000 to nearly 1 million in 2005.14 Efforts to combat malaria by providing bednets and better treatment options are also expanding quickly: the distribution of insecticide-treated bednets increased 10-fold in sub-Saharan Africa between 1999 and 2003.15

Progress toward ensuring environmental sustainability is mixed at best. The MDGs call on countries to cut in half by 2015 the proportion of people without access to safe drinking water and adequate sanitation. Recent analyses suggest that the world is on track to meet the drinking water target: the share of people using drinking water from improved sources rose from 78 percent in 1990 to 83 percent in 2004.16 But more than 1 billion people worldwide still lack access to an improved water supply, including two out of every five individuals in sub-Saharan Africa.17 And as for sanitation, the picture is substantially worse. Although the share of people in the developing world with access to improved sanitation facilities increased from 49 percent in 1990 to 59 percent in 2004, 2.6 billion people still lack connections to public sewers or even access to simple pit latrines or other improved sanitation facilities.18 Current estimates suggest that the overall 2015 target for sanitation is unlikely to be met.19

The MDGs also call on countries to integrate the principles of sustainable development into country policies and programs and to reverse the loss of environmental resources. At the 2002 World Summit on Sustainable Development in Johannesburg, governments adopted a number of related additional targets, including restoring fisheries to their maximum sustainable yields by 2015 and significantly reducing the rate of biological diversity loss by 2010.20 But progress toward these goals has been inadequate. Jeffrey Sachs, who for several years was Special Advisor for the MDGs to U.N. Secretary-General Kofi Annan, recently noted that there was little awareness of the 2010 biological diversity target and that the goal was not being achieved.21 He called the environment the biggest challenge facing humanity and noted that gains against poverty could be “washed away” by forces such as tropical storms, massive flooding, droughts, loss of snow melt, and desertification.22

Efforts to develop a global partnership for development have also been uneven. On the encouraging side, donor aid to developing countries has risen steadily since 1997, reaching $106 billion in 2005.23 But aid expenditures continue to be unequally distributed, in part due to political calculations. More than 60 percent of the increase in official development assistance (ODA) between 2001 and 2004 went to just three countries—Afghanistan, the Democratic Republic of Congo, and Iraq—which between them are home to fewer than 3 percent of the developing world’s impoverished people.24 Furthermore, stepped-up debt relief has accounted for over half of the increase in ODA since 1997 and three quarters of it in 2005.25 Although this has contributed to a steady reduction in debt service payments for 29 heavily indebted poor countries since 1998, there is no guarantee that it will continue or that governments will channel the savings into efforts to meet the MDGs.26

The United Nations projects that sometime in 2008 more people will live in cities than in rural areas.1 Over the past half-century, the world’s urban population has increased nearly fourfold, from 732 million in 1950 to 3.15 billion in 2005.2 (See Figure 1.) People living in cities accounted for 49 percent of the total population of 6.46 billion in 2005.3

The bulk of future population increase— 88 percent of the growth from 2000 to 2030— is projected to occur in cities of the developing world.4 Asia and Africa, the most rural continents today, are set to double their urban populations to some 3.4 billion by 2030.5

Urbanization has slowed considerably in North America and Europe, where by 1950 more than half the population already lived in cities.6 Latin America, at 77 percent urban, has also gone through this demographic transition.7 Growth in that region’s “megacities”—urban agglomerations with more than 10 million inhabitants—has slowed, although large slum populations continue to grow, thanks to the world’s highest levels of economic and social inequality.8

Africa, currently only 38 percent urban, already has nearly 350 million city dwellers— more than the populations of Canada and the United States combined.9 (See Figure 2.) Urbanization there is more recent and more rapid because of higher population growth, rural poverty, and wars that drive people into cities.10 Lack of infrastructure for the poor, followed by rapid urban growth, has produced large slum populations at high risk of disease and environmental hazards like flooding.11 Worldwide, roughly 1 billion urban dwellers live in slums, defined as areas where people live without one or more of life’s basic necessities: clean water, sanitation, sufficient living space, durable housing, or secure tenure.12

Asia, the world’s most populous region, is roughly 40 percent urban.13 Pacific Asia—the coastal region from Japan to Southeast Asia—has undergone a remarkable economic transformation over the past generation, and China is now the site of 16 of the world’s 20 most polluted cities.14 In western China, South Asia, and interior Asia, urbanization is also rapid, but economic growth has been slower, and poverty burdens nearly a third of India’s urban population.15

Since 1975, more than 200 urban agglomerations in the developing world have grown past 1 million inhabitants, so local governments are facing greater sanitation, housing, transportation, water, energy, and health care needs.16 By 2005, 15 of these were megacities (see Figure 3), although these areas account for only about 9 percent of the total urban population.17 Just over half of the world’s city dwellers live in settlements with fewer than 500,000 inhabitants.18

More than half of the rise in urban population is caused by natural increase.19 But migration is also a leading factor, as economic opportunities and improvements in sanitation and clean water have made city life more desirable. Yet the benefits of urban prosperity are shared unequally, and the poor public health conditions of slums still sicken and kill on a large scale.20

The environmental challenges that cities face vary with the level of economic activity.21 The poorest cities and their slums typically have the worst local hazards, such as diseases spread by dirty water and lack of toilets.22 As a city industrializes, problems at the metropolitan scale, such as air pollution from industry and traffic, tend to worsen first and then improve as economic growth allows for cleaner technologies.23 But a city’s burden on the global environment often increases with economic growth as residents buy more cars, bigger houses, and other consumer goods.24

Yet the economies of scale possible with high-density settlement provide a crucial opportunity to create living patterns in harmony with nature’s rhythms. Urban planners are beginning to embrace the concept of “circular metabolism,” in which much of the waste from the water, food, fuels, and materials that course through cities is reused or recycled.25 Architects are beginning to apply this idea to buildings: the 15-story IBM headquarters in Kuala Lumpur, Malaysia, for example, uses plantings on its exterior to capture water that would otherwise be wasted.26