5
Global Fertility and Population Trends John Bongaarts, PhD1
Semin Reprod Med 2015;33:5–10
Abstract
Keywords
► ► ► ►
population fertility projection policy
Address for correspondence John Bongaarts, PhD, Population Council, One Dag Hammarskjold Plaza (9th floor), New York, NY 10017 (e-mail: [email protected]).
Over the past several decades, the world and most countries have undergone unprecedented demographic change. The most obvious example of this change is the rise in human numbers, and there are also important trends in fertility, family structure, mortality, migration, urbanization, and population aging. This paper summarizes past trends and projections in fertility and population. After reaching 2.5 billion in 1950, the world population grew rapidly to 7.2 billion in 2013 and the projections expect this total to be 10.9 billion by 2100. World regions differ widely in their demographic trends, with rapid population growth and high fertility continuing in the poorest countries, particularly in sub-Saharan Africa, while population decline, population aging, and very low fertility are now a key concern in many developed countries. These trends have important implications for human welfare and are of interest to policy makers. The conclusion comments briefly on policy options to address these adverse trends.
Over the past half century, the world and most countries have undergone more rapid demographic change than in any other comparable period in history. The most obvious example of this change is the rise in human numbers. After reaching 2.5 billion in 1950, the world population grew rapidly to 7.2 billion in 2013.1 Accompanying this rise in population are several other important global demographic trends: average fertility has declined by more than half, people are living longer and healthier lives, migration flows are rising both between and within countries as people search for a better life, populations are aging, and family structures are changing. All these trends have implications for human welfare and are hence of interest to policy makers. This paper will focus on two of these processes: fertility and population change. The first part will describe trends in women’s fertility across world regions and discuss the behaviors and determinants of changing reproductive behavior. The second part examines trends in population size and age structure across world regions and discusses their implications. The conclusion will comment briefly on policy options to address adverse trends.
Issue Theme Global Women’s Health: Challenges and Opportunities; Guest Editor, Eli Y. Adashi, MD, MS, MA (ad eundem), CPE, FACOG
Fertility Fertility Trends and Projections Estimates and future projections of fertility levels for all countries and regions are available from the United Nations Population Division.1 ►Fig. 1 presents estimates from 1950 to 2010 and projections to 2050, as measured by the total fertility rate (i.e., the average number of births over a woman’s lifetime assuming the current conditions). In the 1950s, the total fertility rates in Asia, Latin America, and Africa were high and virtually stable at around six births per woman on average. This high level of fertility reflects a near absence of birth control, a condition that has prevailed for centuries before the middle of the 20th century. In the late 1960s, a rapid decline in fertility started nearly simultaneously in Asia and Latin America. In contrast, Africa has experienced only limited reproductive change. As a result of these divergent past trends, fertility levels in 2005 to 2010 differed widely among regions from a high of 5.0 births per woman (bpw) in Africa to 2.5 bpw in Asia and Latin America. Average fertility in North America and Europe reached relatively low levels in
Copyright © 2015 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662.
DOI http://dx.doi.org/ 10.1055/s-0034-1395272. ISSN 1526-8004.
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1 Population Council, New York, New York
Global Fertility and Population Trends
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Fig. 1 Fertility estimates (1950–2010) and projections (2010–2050) by region. (Data from United Nations. World population prospects: the 2012 revision. New York: United Nations, 2013.).
the early 1950s and has since declined to 2.0 bpw in North America and to 1.4 bpw in Europe. The decline in the average fertility of the developing world from six to three births per woman in recent decades has been very rapid, going by historical standards and was not expected in the 1960s and 1970s. UN projections for the developing world assume that the total fertility rate will eventually reach and then fall slightly below the so-called replacement level of just above 2 bpw in all regions (see ►Fig. 1). For regions that have already achieved below replacement fertility, a small rise is expected. Replacement fertility represents the level at which each generation exactly replaces the previous one, thus leading to zero population growth (in the absence of mortality change and migration). Below-replacement fertility produces, in the long run, population decline. As is evident from ►Fig. 1, the total fertility rates in Asia and Latin America are now very close to the replacement level, but Africa is on a much slower trajectory toward replacement fertility. High fertility therefore remains a key cause of future population growth in Africa. In contrast, the already low fertility of Europe and North America is expected to remain below replacement and is the main cause of population decline in a few countries.
A full discussion of the extensive literature on the determinants of fertility is beyond the scope of this paper. Nevertheless, to demonstrate the plausibility of the conventional theory, ►Fig. 2 plots the association between the level of fertility and GDP per capita in 2010 for 174 countries. These variables have a clear inverse relationship. At one end of the spectrum are the poorest countries with the lowest GDP per capita and fertility rates around six or seven births per women. At the other end of the spectrum are countries with GDP per capita above 10,000 that typically have fertility rates around or below two births per women. Similar correlations between fertility and other development indicators, such as percent urban, level of education, and life expectancy (data not shown), are found at the country level. Despite these broad inverse associations between fertility and development, the correlations are far from perfect and countries can fall above and below the general trend line for a range of reasons including active government policies to increase or decrease fertility (see further discussion).
Population Growth Current population growth rates vary widely among countries, ranging from over 3% per year in several African countries to less than 0% in a few European and Asian countries (see ►Fig. 3). Not surprisingly, population growth rates of countries are highly correlated with their levels of fertility (see ►Fig. 4). To discuss these diverse demographic conditions and their implications, countries are grouped into four broad categories (corresponding to the circles in ►Fig. 4)5: 1. Rapid growth and high fertility. This group includes most of the poorest countries in the world: much of sub-Saharan Africa, parts of South Asia (Pakistan and Afghanistan), and the Arabian Peninsula (which also includes rich oil-producers with small populations), and a few small countries in Latin America. Population size in this group is expected to continue to expand at a rapid pace, in most cases more than doubling in size by 2050. This rapid population growth is an obstacle to development and makes it difficult
Why Fertility Declines Conventional demographic theory argues that decline in fertility is due to social and economic development.2–4 The chain of causation from development to fertility includes several steps: First, development (i.e., rising industrialization, urbanization, education, incomes, and effective public health interventions) causes a decline in the benefits of children (e.g., for labor and old age security) and a rise in their costs (e.g., for education). This changing cost/benefit ratio leads parents to want fewer children and hence to a demand for birth control. Second, the rise in contraceptive use in response to this demand results in lower fertility. Family planning programs facilitate this transition by reducing the cost of birth control and thus raising the level of implementation of the demand for contraception. Seminars in Reproductive Medicine
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Fig. 2 Fertility by GDP per capita (PPP $2005) by country. (Data from World Development Indicators Databank, World Bank). GDP, gross domestic product; PPP, purchasing power parity.
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Fig. 3 Annual population growth in 2010, rate by country. (Data from World Development Indicators Databank, World Bank).
to be optimistic about the future of this group. There are several reasons for concern: Environmental degradation: Global environmental problems (e.g., climate change and decreasing biodiversity) receive much media and scientific attention in the West, but are not a high priority for policy makers in poor countries, except where substantial populations live in low-lying coastal areas (e.g., Bangladesh). Instead, most developing countries have critical local environmental problems that require urgent attention, including shortage of fresh water and arable land and pollution of water, air, and soil.6 Environmental stresses have been building up over time and are likely to become much more severe as populations and economies expand further. Economic stagnation: In poor societies, population sizes often double in two or three decades. As a result, industries, housing, schools, health clinics, and infrastructure
Fig. 4 Annual population growth rate by total fertility rate, by country. (Data from World Development Indicators Databank, World Bank).
must be built at least at the same rate to prevent deterioration in the standards of living. Many communities are unable to keep up, as is evident from high unemployment rates, explosive growth of slum populations, overcrowded schools and health facilities, and dilapidated public infrastructure (i.e., roads, bridges, sewage systems, piped water, and electric power). Age of population: In addition, rapidly growing populations have young age structures. The resulting low ratio of workers to dependents decreases the standards of living and makes it more difficult to invest in the physical and human capital needed for expanding economies. The size of the formal labor force is also limited by the need for women to remain at home to take care of large families. All these demographic factors hamper economic growth.7 Maternal mortality: High birth rates imply frequent childbearing throughout the potential reproductive years. Each pregnancy is associated with a risk of death, and this risk rises with age of the mother and the order of the pregnancy. In the least developed countries, the lifetime risk of dying from pregnancy-related causes is over 4% and many more women suffer related health problems or disabilities.8 In contrast, the lifetime risk of maternal mortality in the developed world is a small fraction of a percent, because women have fewer pregnancies and the risk of death associated with each pregnancy is very small. Political unrest: Half the population of the least developed world is under age 20. Unemployment is widespread because economies are unable to provide jobs for the rapidly growing number of young people seeking to enter the labor force. Vigorous competition for limited numbers of jobs leads to low wages, which in turn contributes to poverty. The presence of large numbers of unemployed Seminars in Reproductive Medicine
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Global Fertility and Population Trends
Global Fertility and Population Trends
Bongaarts
and frustrated males likely contributes to socioeconomic tensions, high crime rates, and political instability.9 Of course, population growth is not the only cause of poverty in the developing world. Nevertheless, population growth has pervasive adverse effects on societies and hinders development efforts. Therefore, poor countries would be better off with lower population growth rates. 2. Moderate growth and intermediate fertility. This group of countries includes large countries such as India and Indonesia as well as most of North Africa and Latin America. In these populations the adverse consequences of very rapid growth are being reduced. In particular, the decline in fertility has multiple benefits over time: stresses on public services and infrastructure become less acute, maternal and infant mortality benefit from the widespread use of contraception, the economy receives a boost (the so-called demographic dividend) as the labor force grows more rapidly than the dependent young and old, and women can start working for wages outside the household instead of devoting most of their time to childrearing.10 3. Little or no growth and fertility near replacement. This group includes the most advanced countries (e.g., North America and much of Europe) as well as several large middle-income countries (e.g., China and Brazil). While the stresses of rapid population growth have disappeared in these countries, most have high consumption levels and hence are major contributors to global environmental problems such as climate change. In addition, they now face a new demographic challenge: population aging. Aging has been underway for several decades and is expected to continue at a rapid pace for the foreseeable future. For example, between 2010 and 2050, the proportion of elderly (ages 65 þ ) is projected to rise from 16.3 to 26.9% in Europe, from 13.2 to 21.8% in North America, from 23.0 to 36.5% in Japan, and from 8.4 to 23.9% in China.1 These trends have major implications for the welfare of the elderly and the economy. In the rapidly aging developing countries (e.g., China), support has traditionally been provided by families, but this support is under threat because parents have fewer children than in the past and children increasingly move away from home (e.g., in search of employment opportunities). Unfortunately, few
developing countries have created formal institutions to take over this care. In contrast, in the developed world, much of the support for the elderly is now provided by public pensions and health care. These programs are popular and have successfully reduced poverty among the elderly. But the sustainability of public pension and health care systems are being threatened as their costs become increasingly burdensome to tax payers. The aging rich parts of the world are now struggling to address these fiscal stresses on pension and health care systems because failure to do so could have severe economic consequences. 4. Negative growth, below replacement fertility. A small but growing number of countries are now declining in size. Japan, Germany, Russia, and much of Eastern Europe are currently experiencing negative growth. By 2050, Russia is projected to have 16% fewer people and Japan 15%. In addition, this group of countries will experience the highest population aging with proportions aged 65þ reaching over 30% by 2050. The key demographic cause of negative growth is persistent fertility substantially below the replacement level.
Long-Range Projections The positive growth rates observed in most countries today are expected to be maintained for varying periods into the future, thus leading to substantial population increases. ►Table 1 summarizes the most recent UN medium projections for the world and its major regions.1 The population of the world is expected to reach 10.9 billion in 2100, adding 4 billion to the 2010 population of 6.9 billion. Projected population trends vary widely among world regions (see ►Table 1). In 2010, Asia had a population of 4.17 billion, more than half of the world total, and its population is expected to grow by half a billion to 4.71 billion by 2100. Africa, with 1.03 billion inhabitants in 2010, is likely to experience by far the most rapid expansion, quadrupling in size by 2010. Latin America, with 0.6 billion in 2010, is the smallest of the regions of the developing world with a growth pattern broadly similar to Asia’s. Trends for the two principal regions in the developed world will diverge between 2010 and 2100: an increase from 0.35 to 0.51 billion in Northern America, but a decline from 0.74 to 0.64 billion in Europe.
Table 1 Population estimates (1950–2010) and projections to 2100 in billions 1950
2010
2050
2100
Increase 2010–2100 Absolute
Percent
World
2.53
6.92
9.55
10.85
3.94
57
Africa
0.23
1.03
2.39
4.18
3.15
306
Asia
1.40
4.17
5.16
4.71
0.55
13
Latin America
0.17
0.60
0.78
0.74
0.14
23
North America
0.17
0.35
0.45
0.51
0.17
48
Europe
0.55
0.74
0.71
0.64
0.10
14
Source: Data from United Nations. World population prospects: the 2012 revision. New York: United Nations, 2013. Seminars in Reproductive Medicine
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One consequence of these diverse regional growth rates is that the regional distribution of population will shift significantly over time. According to the UN projections from 2010 to 2100, Africa’s share of the world population will rise from 15 to 39%, while the shares all other regions will decline: from 60.2 to 43.4% in Asia, from 8.6 to 6.8% for Latin America, from 5.0 to 4.7% in North America, and from 10.7 to 5.9% for Europe.
Policy Options As noted, projections for the next decades expect a highly divergent world, with stagnation or potential decline in parts of the developed world and continued rapid growth in the least developed regions. A wide range of policies are available for governments concerned about the adverse effects of these trends. In countries with very low fertility (e.g., in Europe and East Asia), efforts to encourage childbearing are being considered to reverse or mitigate the adverse impact of rapid population aging and population decline. The opposite is true in much of the developing world where rapid population growth remains a key concern.
Addressing High Fertility: The Case for Family Planning Programs Since the 1960s, alongside investments to improve education and health, the main policy response to rapid population growth has been the implementation of voluntary family planning programs that provide information about, and access to, contraception. The key rationale for such programs is a well-documented substantial level of unwanted and unplanned childbearing and an unsatisfied demand for contraception. Today, 80 million unintended pregnancies occur annually in the developing world. These pregnancies end in abortions (40 million), unintended births (30 million), or miscarriages (10 million).11 Among the reasons for the unmet need for contraception are a lack of knowledge about the existence and availability of contraception, insufficient contraceptive supplies and services, the cost of contraception, fear of side effects, and opposition from spouses and other family members. To be successful in reducing unintended pregnancies, family planning programs must go beyond simply providing physical access to supplies and services and reduce or eliminate these other obstacles as well.12 The most persuasive evidence that such programs work come from experiments, such as the one undertaken in the Matlab district of Bangladesh starting in 1977.13 In the experimental area of Matlab, high-quality services were provided that aimed at reducing all obstacles to adopting contraception, while the control area received the same very limited family planning services as the rest of the country. The intervention provided free services and supplies, home visits by well-trained female family planning workers, and comprehensive multimedia communication. Outreach to husbands, village leaders, and religious leaders addressed potential social and familial objections from men. The results were clear-cut. Contraceptive use jumped from 5 to 33% in the experimental area, while little changed in the
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control area. As a result, fertility declined rapidly in the experimental area and a difference of approximately 1.5 births per woman between the experimental and control areas was observed in subsequent years. Among the longterm consequences of this difference was higher education of children, greater asset accumulation, and greater use of preventive health services in the experimental area.14 This experiment demonstrated that family planning programs can succeed even in highly traditional societies. Contemporary evidence is fully consistent with the Matlab record.15 For example, countries that have suddenly implemented family planning programs (e.g., Iran in the 1989 and Rwanda in the mid-2000s) have seen very rapid subsequent changes in reproductive behavior. Iran’s fertility declined at an extraordinary pace from 5.6 bpw in the late 1980s to 2.6 bpw a decade later. In Rwanda, the total fertility rate dropped from 6.1 in 2005 to 4.6 in 2010, and the use of modern methods of contraception jumped from 10 to 45%. Both countries implemented information and communications programs that included messages about the benefits of smaller families. Any program-induced acceleration of fertility decline changes the future trajectory of population growth. This impact can be large as is demonstrated by a comparison of alternative UN population projections for sub-Saharan Africa. According to the medium-variant projection, the population will quadruple from 0.83 billion in 2010 to 3.8 billion in 2100.1 With major new investments in family planning, the fertility trajectory could easily be cut by a half birth per woman, leading to the low variant that projects more than a billion fewer people by 2100.
Addressing Very Low Fertility: Supporting Couples to Achieve Their Fertility Preferences The identification and implementation of ways to avert the adverse future consequences of low fertility and rapid population aging represent urgent new public policy challenges. Many countries with low fertility are now considering pronatalist policies. The design of such policies is facilitated by the fact that actual fertility is lower than the desired family size in many developed countries.16 As a result, policies can focus on closing the gap between ideal and actual period fertility. The main cause of this gap is the high cost of raising children and difficulty that women and men experience in combining parenthood and participation in the labor force. The cost of children include the direct economic costs associated with the bearing and rearing of children and the opportunity costs of childbearing for working parents. Opportunity costs have increased over time with rising levels of women’s education and labor force participation. In addition, unemployment among young adults creates economic uncertainty and delays childbearing. Most of the actual proposals that have been implemented or are under discussion focus on measures to reduce economic costs of childbearing and to make it easier for women to work when their children are young. A wide range of options exists. Countries in Northern and Western Europe with generous family support measures such as subsidized Seminars in Reproductive Medicine
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Global Fertility and Population Trends
Global Fertility and Population Trends
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childcare, reduced taxes for families with children, and paid parental leaves, have somewhat higher fertility than elsewhere in Europe. These observations about the potential impact of interventions are consistent with the conclusions of past reviews of the evidence that generally find modest effects for them.17–20 The most recent assessment by Greulich and Thévenon compares the impact of various policies and concludes, “Policy levers do not all have the same weight..: incash benefits covering childhood after the year of childbirth and the provision of childcare services for children under age three have a larger potential influence on fertility than leave entitlements and benefits granted around childbirth.”17
Conclusion
4 Notestein F. Population—the long view. In: Theodore W. Schultz,
5 6
7
8 9
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The massive demographic transformations that are occurring in countries around the world have a range of often adverse impacts on human welfare. In the poorest countries, fertility and population growth are still high, leading to slower economic growth, poorer health, and environmental degradation, which make it more difficult to achieve sustained development. In these countries, unplanned pregnancies and births remain common. The most direct and effective way to address this issue is to implement comprehensive family planning programs, which have a record of success if sufficient resources backed by political commitment are provided. The developed world faces a very different and relatively new demographic challenge: an aging population that is the consequence of very low fertility. Policy solutions are still evolving, but the general approach taken is to either reduce the cost of childbearing or to make it easier for women to combine motherhood and employment.
11
12
13
14
15
16
17
References 1 United Nations. World Population Prospects: The 2012 Revision.
New York: United Nations; 2013 2 Bryant J. Theories of fertility decline and the evidence from development indicators. Popul Dev Rev 2007;33(1):101–127 3 Notestein F. Economic problems of population change. In: Proceedings of the Eighth International Conference of Agricultural Economists. London: Oxford University Press; 1953:13–31
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ed. Food for the World. Chicago, IL: Chicago University Press; 1945: 36–57 Ezeh AC, Bongaarts J, Mberu B. Global population trends and policy options. Lancet 2012;380(9837):142–148 Alexandratos N. Countries with rapid population growth and resource constraints: issues of food, agriculture, and development. Popul Dev Rev 2005;31:237–258 Birdsall N, Kelley AC, Sinding SW, eds. Population Matters: Demographic Change, Economic Growth, and Poverty in the Developing World. Oxford: Oxford University Press; 2001 World Bank. World Development Indicators Data bank Urdal H. A clash of generations? Youth bulges and political violence. Paper presented at: United Nations Expert Group Meeting on Adolescents, Youth and Development; July 21–22, 2011; New York Bloom DE, Canning D, Sevilla J. The Demographic Dividend: A New Perspective on the Economic Consequences of Population Change. Santa Monica, CA: RAND; 2003 Susheela S, Darroch JE. Adding It Up: Costs and Benefits of Contraceptive Services—Estimates for 2012. New York: Guttmacher Institute; 2012 Cleland J, Bernstein S, Ezeh A, Faundes A, Glasier A, Innis J. Family planning: the unfinished agenda. Lancet 2006;368(9549): 1810–1827 Cleland J, Phillips JF, Amin S, Kamal GM. The Determinants of Reproductive Change in Bangladesh: Success in a Challenging Environment. Washington, DC: World Bank; 1994 Joshi S, Schultz TP. Family planning as an investment in development: evaluation of a program’s consequences in Matlab, Bangladesh. Yale University Economic Growth Center Discussion Paper No. 951. New Haven: Yale University; 2007 Bongaarts J, Cleland J, Townsend J, Bertrand J, Das Gupta M. Family Planning Programs for the 21st Century: Rationale and Design. New York: Population Council; 2012 Bongaarts J. What Can Fertility Indicators Tell Us about Pronatalist Policy Options? Vienna Yearbook of Population Research. 2008: 39–56 Luci-Greulich A, Thévenon O. The impact of family policies on fertility trends in developed countries. Eur J Popul 2013;29(4): 387–416 Caldwell J, Caldwell P, McDonald P. Policy responses to low fertility and its consequences: a global survey. J Popul Res 2002;19:1–24 Gauthier A. The impact of family policies on fertility in industrialized countries: a review of the literature. Popul Res Policy Rev 2007;26:323–346 McDonald P. Low fertility and the state: the efficacy of policy. Popul Dev Rev 2006;32:485–510
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Global Fertility and Population Trends John Bongaarts, PhD1
Semin Reprod Med 2015;33:5–10
Abstract
Keywords
► ► ► ►
population fertility projection policy
Address for correspondence John Bongaarts, PhD, Population Council, One Dag Hammarskjold Plaza (9th floor), New York, NY 10017 (e-mail: [email protected]).
Over the past several decades, the world and most countries have undergone unprecedented demographic change. The most obvious example of this change is the rise in human numbers, and there are also important trends in fertility, family structure, mortality, migration, urbanization, and population aging. This paper summarizes past trends and projections in fertility and population. After reaching 2.5 billion in 1950, the world population grew rapidly to 7.2 billion in 2013 and the projections expect this total to be 10.9 billion by 2100. World regions differ widely in their demographic trends, with rapid population growth and high fertility continuing in the poorest countries, particularly in sub-Saharan Africa, while population decline, population aging, and very low fertility are now a key concern in many developed countries. These trends have important implications for human welfare and are of interest to policy makers. The conclusion comments briefly on policy options to address these adverse trends.
Over the past half century, the world and most countries have undergone more rapid demographic change than in any other comparable period in history. The most obvious example of this change is the rise in human numbers. After reaching 2.5 billion in 1950, the world population grew rapidly to 7.2 billion in 2013.1 Accompanying this rise in population are several other important global demographic trends: average fertility has declined by more than half, people are living longer and healthier lives, migration flows are rising both between and within countries as people search for a better life, populations are aging, and family structures are changing. All these trends have implications for human welfare and are hence of interest to policy makers. This paper will focus on two of these processes: fertility and population change. The first part will describe trends in women’s fertility across world regions and discuss the behaviors and determinants of changing reproductive behavior. The second part examines trends in population size and age structure across world regions and discusses their implications. The conclusion will comment briefly on policy options to address adverse trends.
Issue Theme Global Women’s Health: Challenges and Opportunities; Guest Editor, Eli Y. Adashi, MD, MS, MA (ad eundem), CPE, FACOG
Fertility Fertility Trends and Projections Estimates and future projections of fertility levels for all countries and regions are available from the United Nations Population Division.1 ►Fig. 1 presents estimates from 1950 to 2010 and projections to 2050, as measured by the total fertility rate (i.e., the average number of births over a woman’s lifetime assuming the current conditions). In the 1950s, the total fertility rates in Asia, Latin America, and Africa were high and virtually stable at around six births per woman on average. This high level of fertility reflects a near absence of birth control, a condition that has prevailed for centuries before the middle of the 20th century. In the late 1960s, a rapid decline in fertility started nearly simultaneously in Asia and Latin America. In contrast, Africa has experienced only limited reproductive change. As a result of these divergent past trends, fertility levels in 2005 to 2010 differed widely among regions from a high of 5.0 births per woman (bpw) in Africa to 2.5 bpw in Asia and Latin America. Average fertility in North America and Europe reached relatively low levels in
Copyright © 2015 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662.
DOI http://dx.doi.org/ 10.1055/s-0034-1395272. ISSN 1526-8004.
This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.
1 Population Council, New York, New York
Global Fertility and Population Trends
Bongaarts
Fig. 1 Fertility estimates (1950–2010) and projections (2010–2050) by region. (Data from United Nations. World population prospects: the 2012 revision. New York: United Nations, 2013.).
the early 1950s and has since declined to 2.0 bpw in North America and to 1.4 bpw in Europe. The decline in the average fertility of the developing world from six to three births per woman in recent decades has been very rapid, going by historical standards and was not expected in the 1960s and 1970s. UN projections for the developing world assume that the total fertility rate will eventually reach and then fall slightly below the so-called replacement level of just above 2 bpw in all regions (see ►Fig. 1). For regions that have already achieved below replacement fertility, a small rise is expected. Replacement fertility represents the level at which each generation exactly replaces the previous one, thus leading to zero population growth (in the absence of mortality change and migration). Below-replacement fertility produces, in the long run, population decline. As is evident from ►Fig. 1, the total fertility rates in Asia and Latin America are now very close to the replacement level, but Africa is on a much slower trajectory toward replacement fertility. High fertility therefore remains a key cause of future population growth in Africa. In contrast, the already low fertility of Europe and North America is expected to remain below replacement and is the main cause of population decline in a few countries.
A full discussion of the extensive literature on the determinants of fertility is beyond the scope of this paper. Nevertheless, to demonstrate the plausibility of the conventional theory, ►Fig. 2 plots the association between the level of fertility and GDP per capita in 2010 for 174 countries. These variables have a clear inverse relationship. At one end of the spectrum are the poorest countries with the lowest GDP per capita and fertility rates around six or seven births per women. At the other end of the spectrum are countries with GDP per capita above 10,000 that typically have fertility rates around or below two births per women. Similar correlations between fertility and other development indicators, such as percent urban, level of education, and life expectancy (data not shown), are found at the country level. Despite these broad inverse associations between fertility and development, the correlations are far from perfect and countries can fall above and below the general trend line for a range of reasons including active government policies to increase or decrease fertility (see further discussion).
Population Growth Current population growth rates vary widely among countries, ranging from over 3% per year in several African countries to less than 0% in a few European and Asian countries (see ►Fig. 3). Not surprisingly, population growth rates of countries are highly correlated with their levels of fertility (see ►Fig. 4). To discuss these diverse demographic conditions and their implications, countries are grouped into four broad categories (corresponding to the circles in ►Fig. 4)5: 1. Rapid growth and high fertility. This group includes most of the poorest countries in the world: much of sub-Saharan Africa, parts of South Asia (Pakistan and Afghanistan), and the Arabian Peninsula (which also includes rich oil-producers with small populations), and a few small countries in Latin America. Population size in this group is expected to continue to expand at a rapid pace, in most cases more than doubling in size by 2050. This rapid population growth is an obstacle to development and makes it difficult
Why Fertility Declines Conventional demographic theory argues that decline in fertility is due to social and economic development.2–4 The chain of causation from development to fertility includes several steps: First, development (i.e., rising industrialization, urbanization, education, incomes, and effective public health interventions) causes a decline in the benefits of children (e.g., for labor and old age security) and a rise in their costs (e.g., for education). This changing cost/benefit ratio leads parents to want fewer children and hence to a demand for birth control. Second, the rise in contraceptive use in response to this demand results in lower fertility. Family planning programs facilitate this transition by reducing the cost of birth control and thus raising the level of implementation of the demand for contraception. Seminars in Reproductive Medicine
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No. 1/2015
Fig. 2 Fertility by GDP per capita (PPP $2005) by country. (Data from World Development Indicators Databank, World Bank). GDP, gross domestic product; PPP, purchasing power parity.
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6
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Fig. 3 Annual population growth in 2010, rate by country. (Data from World Development Indicators Databank, World Bank).
to be optimistic about the future of this group. There are several reasons for concern: Environmental degradation: Global environmental problems (e.g., climate change and decreasing biodiversity) receive much media and scientific attention in the West, but are not a high priority for policy makers in poor countries, except where substantial populations live in low-lying coastal areas (e.g., Bangladesh). Instead, most developing countries have critical local environmental problems that require urgent attention, including shortage of fresh water and arable land and pollution of water, air, and soil.6 Environmental stresses have been building up over time and are likely to become much more severe as populations and economies expand further. Economic stagnation: In poor societies, population sizes often double in two or three decades. As a result, industries, housing, schools, health clinics, and infrastructure
Fig. 4 Annual population growth rate by total fertility rate, by country. (Data from World Development Indicators Databank, World Bank).
must be built at least at the same rate to prevent deterioration in the standards of living. Many communities are unable to keep up, as is evident from high unemployment rates, explosive growth of slum populations, overcrowded schools and health facilities, and dilapidated public infrastructure (i.e., roads, bridges, sewage systems, piped water, and electric power). Age of population: In addition, rapidly growing populations have young age structures. The resulting low ratio of workers to dependents decreases the standards of living and makes it more difficult to invest in the physical and human capital needed for expanding economies. The size of the formal labor force is also limited by the need for women to remain at home to take care of large families. All these demographic factors hamper economic growth.7 Maternal mortality: High birth rates imply frequent childbearing throughout the potential reproductive years. Each pregnancy is associated with a risk of death, and this risk rises with age of the mother and the order of the pregnancy. In the least developed countries, the lifetime risk of dying from pregnancy-related causes is over 4% and many more women suffer related health problems or disabilities.8 In contrast, the lifetime risk of maternal mortality in the developed world is a small fraction of a percent, because women have fewer pregnancies and the risk of death associated with each pregnancy is very small. Political unrest: Half the population of the least developed world is under age 20. Unemployment is widespread because economies are unable to provide jobs for the rapidly growing number of young people seeking to enter the labor force. Vigorous competition for limited numbers of jobs leads to low wages, which in turn contributes to poverty. The presence of large numbers of unemployed Seminars in Reproductive Medicine
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Global Fertility and Population Trends
Global Fertility and Population Trends
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and frustrated males likely contributes to socioeconomic tensions, high crime rates, and political instability.9 Of course, population growth is not the only cause of poverty in the developing world. Nevertheless, population growth has pervasive adverse effects on societies and hinders development efforts. Therefore, poor countries would be better off with lower population growth rates. 2. Moderate growth and intermediate fertility. This group of countries includes large countries such as India and Indonesia as well as most of North Africa and Latin America. In these populations the adverse consequences of very rapid growth are being reduced. In particular, the decline in fertility has multiple benefits over time: stresses on public services and infrastructure become less acute, maternal and infant mortality benefit from the widespread use of contraception, the economy receives a boost (the so-called demographic dividend) as the labor force grows more rapidly than the dependent young and old, and women can start working for wages outside the household instead of devoting most of their time to childrearing.10 3. Little or no growth and fertility near replacement. This group includes the most advanced countries (e.g., North America and much of Europe) as well as several large middle-income countries (e.g., China and Brazil). While the stresses of rapid population growth have disappeared in these countries, most have high consumption levels and hence are major contributors to global environmental problems such as climate change. In addition, they now face a new demographic challenge: population aging. Aging has been underway for several decades and is expected to continue at a rapid pace for the foreseeable future. For example, between 2010 and 2050, the proportion of elderly (ages 65 þ ) is projected to rise from 16.3 to 26.9% in Europe, from 13.2 to 21.8% in North America, from 23.0 to 36.5% in Japan, and from 8.4 to 23.9% in China.1 These trends have major implications for the welfare of the elderly and the economy. In the rapidly aging developing countries (e.g., China), support has traditionally been provided by families, but this support is under threat because parents have fewer children than in the past and children increasingly move away from home (e.g., in search of employment opportunities). Unfortunately, few
developing countries have created formal institutions to take over this care. In contrast, in the developed world, much of the support for the elderly is now provided by public pensions and health care. These programs are popular and have successfully reduced poverty among the elderly. But the sustainability of public pension and health care systems are being threatened as their costs become increasingly burdensome to tax payers. The aging rich parts of the world are now struggling to address these fiscal stresses on pension and health care systems because failure to do so could have severe economic consequences. 4. Negative growth, below replacement fertility. A small but growing number of countries are now declining in size. Japan, Germany, Russia, and much of Eastern Europe are currently experiencing negative growth. By 2050, Russia is projected to have 16% fewer people and Japan 15%. In addition, this group of countries will experience the highest population aging with proportions aged 65þ reaching over 30% by 2050. The key demographic cause of negative growth is persistent fertility substantially below the replacement level.
Long-Range Projections The positive growth rates observed in most countries today are expected to be maintained for varying periods into the future, thus leading to substantial population increases. ►Table 1 summarizes the most recent UN medium projections for the world and its major regions.1 The population of the world is expected to reach 10.9 billion in 2100, adding 4 billion to the 2010 population of 6.9 billion. Projected population trends vary widely among world regions (see ►Table 1). In 2010, Asia had a population of 4.17 billion, more than half of the world total, and its population is expected to grow by half a billion to 4.71 billion by 2100. Africa, with 1.03 billion inhabitants in 2010, is likely to experience by far the most rapid expansion, quadrupling in size by 2010. Latin America, with 0.6 billion in 2010, is the smallest of the regions of the developing world with a growth pattern broadly similar to Asia’s. Trends for the two principal regions in the developed world will diverge between 2010 and 2100: an increase from 0.35 to 0.51 billion in Northern America, but a decline from 0.74 to 0.64 billion in Europe.
Table 1 Population estimates (1950–2010) and projections to 2100 in billions 1950
2010
2050
2100
Increase 2010–2100 Absolute
Percent
World
2.53
6.92
9.55
10.85
3.94
57
Africa
0.23
1.03
2.39
4.18
3.15
306
Asia
1.40
4.17
5.16
4.71
0.55
13
Latin America
0.17
0.60
0.78
0.74
0.14
23
North America
0.17
0.35
0.45
0.51
0.17
48
Europe
0.55
0.74
0.71
0.64
0.10
14
Source: Data from United Nations. World population prospects: the 2012 revision. New York: United Nations, 2013. Seminars in Reproductive Medicine
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One consequence of these diverse regional growth rates is that the regional distribution of population will shift significantly over time. According to the UN projections from 2010 to 2100, Africa’s share of the world population will rise from 15 to 39%, while the shares all other regions will decline: from 60.2 to 43.4% in Asia, from 8.6 to 6.8% for Latin America, from 5.0 to 4.7% in North America, and from 10.7 to 5.9% for Europe.
Policy Options As noted, projections for the next decades expect a highly divergent world, with stagnation or potential decline in parts of the developed world and continued rapid growth in the least developed regions. A wide range of policies are available for governments concerned about the adverse effects of these trends. In countries with very low fertility (e.g., in Europe and East Asia), efforts to encourage childbearing are being considered to reverse or mitigate the adverse impact of rapid population aging and population decline. The opposite is true in much of the developing world where rapid population growth remains a key concern.
Addressing High Fertility: The Case for Family Planning Programs Since the 1960s, alongside investments to improve education and health, the main policy response to rapid population growth has been the implementation of voluntary family planning programs that provide information about, and access to, contraception. The key rationale for such programs is a well-documented substantial level of unwanted and unplanned childbearing and an unsatisfied demand for contraception. Today, 80 million unintended pregnancies occur annually in the developing world. These pregnancies end in abortions (40 million), unintended births (30 million), or miscarriages (10 million).11 Among the reasons for the unmet need for contraception are a lack of knowledge about the existence and availability of contraception, insufficient contraceptive supplies and services, the cost of contraception, fear of side effects, and opposition from spouses and other family members. To be successful in reducing unintended pregnancies, family planning programs must go beyond simply providing physical access to supplies and services and reduce or eliminate these other obstacles as well.12 The most persuasive evidence that such programs work come from experiments, such as the one undertaken in the Matlab district of Bangladesh starting in 1977.13 In the experimental area of Matlab, high-quality services were provided that aimed at reducing all obstacles to adopting contraception, while the control area received the same very limited family planning services as the rest of the country. The intervention provided free services and supplies, home visits by well-trained female family planning workers, and comprehensive multimedia communication. Outreach to husbands, village leaders, and religious leaders addressed potential social and familial objections from men. The results were clear-cut. Contraceptive use jumped from 5 to 33% in the experimental area, while little changed in the
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control area. As a result, fertility declined rapidly in the experimental area and a difference of approximately 1.5 births per woman between the experimental and control areas was observed in subsequent years. Among the longterm consequences of this difference was higher education of children, greater asset accumulation, and greater use of preventive health services in the experimental area.14 This experiment demonstrated that family planning programs can succeed even in highly traditional societies. Contemporary evidence is fully consistent with the Matlab record.15 For example, countries that have suddenly implemented family planning programs (e.g., Iran in the 1989 and Rwanda in the mid-2000s) have seen very rapid subsequent changes in reproductive behavior. Iran’s fertility declined at an extraordinary pace from 5.6 bpw in the late 1980s to 2.6 bpw a decade later. In Rwanda, the total fertility rate dropped from 6.1 in 2005 to 4.6 in 2010, and the use of modern methods of contraception jumped from 10 to 45%. Both countries implemented information and communications programs that included messages about the benefits of smaller families. Any program-induced acceleration of fertility decline changes the future trajectory of population growth. This impact can be large as is demonstrated by a comparison of alternative UN population projections for sub-Saharan Africa. According to the medium-variant projection, the population will quadruple from 0.83 billion in 2010 to 3.8 billion in 2100.1 With major new investments in family planning, the fertility trajectory could easily be cut by a half birth per woman, leading to the low variant that projects more than a billion fewer people by 2100.
Addressing Very Low Fertility: Supporting Couples to Achieve Their Fertility Preferences The identification and implementation of ways to avert the adverse future consequences of low fertility and rapid population aging represent urgent new public policy challenges. Many countries with low fertility are now considering pronatalist policies. The design of such policies is facilitated by the fact that actual fertility is lower than the desired family size in many developed countries.16 As a result, policies can focus on closing the gap between ideal and actual period fertility. The main cause of this gap is the high cost of raising children and difficulty that women and men experience in combining parenthood and participation in the labor force. The cost of children include the direct economic costs associated with the bearing and rearing of children and the opportunity costs of childbearing for working parents. Opportunity costs have increased over time with rising levels of women’s education and labor force participation. In addition, unemployment among young adults creates economic uncertainty and delays childbearing. Most of the actual proposals that have been implemented or are under discussion focus on measures to reduce economic costs of childbearing and to make it easier for women to work when their children are young. A wide range of options exists. Countries in Northern and Western Europe with generous family support measures such as subsidized Seminars in Reproductive Medicine
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Global Fertility and Population Trends
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childcare, reduced taxes for families with children, and paid parental leaves, have somewhat higher fertility than elsewhere in Europe. These observations about the potential impact of interventions are consistent with the conclusions of past reviews of the evidence that generally find modest effects for them.17–20 The most recent assessment by Greulich and Thévenon compares the impact of various policies and concludes, “Policy levers do not all have the same weight..: incash benefits covering childhood after the year of childbirth and the provision of childcare services for children under age three have a larger potential influence on fertility than leave entitlements and benefits granted around childbirth.”17
Conclusion
4 Notestein F. Population—the long view. In: Theodore W. Schultz,
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7
8 9
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The massive demographic transformations that are occurring in countries around the world have a range of often adverse impacts on human welfare. In the poorest countries, fertility and population growth are still high, leading to slower economic growth, poorer health, and environmental degradation, which make it more difficult to achieve sustained development. In these countries, unplanned pregnancies and births remain common. The most direct and effective way to address this issue is to implement comprehensive family planning programs, which have a record of success if sufficient resources backed by political commitment are provided. The developed world faces a very different and relatively new demographic challenge: an aging population that is the consequence of very low fertility. Policy solutions are still evolving, but the general approach taken is to either reduce the cost of childbearing or to make it easier for women to combine motherhood and employment.
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12
13
14
15
16
17
References 1 United Nations. World Population Prospects: The 2012 Revision.
New York: United Nations; 2013 2 Bryant J. Theories of fertility decline and the evidence from development indicators. Popul Dev Rev 2007;33(1):101–127 3 Notestein F. Economic problems of population change. In: Proceedings of the Eighth International Conference of Agricultural Economists. London: Oxford University Press; 1953:13–31
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ed. Food for the World. Chicago, IL: Chicago University Press; 1945: 36–57 Ezeh AC, Bongaarts J, Mberu B. Global population trends and policy options. Lancet 2012;380(9837):142–148 Alexandratos N. Countries with rapid population growth and resource constraints: issues of food, agriculture, and development. Popul Dev Rev 2005;31:237–258 Birdsall N, Kelley AC, Sinding SW, eds. Population Matters: Demographic Change, Economic Growth, and Poverty in the Developing World. Oxford: Oxford University Press; 2001 World Bank. World Development Indicators Data bank Urdal H. A clash of generations? Youth bulges and political violence. Paper presented at: United Nations Expert Group Meeting on Adolescents, Youth and Development; July 21–22, 2011; New York Bloom DE, Canning D, Sevilla J. The Demographic Dividend: A New Perspective on the Economic Consequences of Population Change. Santa Monica, CA: RAND; 2003 Susheela S, Darroch JE. Adding It Up: Costs and Benefits of Contraceptive Services—Estimates for 2012. New York: Guttmacher Institute; 2012 Cleland J, Bernstein S, Ezeh A, Faundes A, Glasier A, Innis J. Family planning: the unfinished agenda. Lancet 2006;368(9549): 1810–1827 Cleland J, Phillips JF, Amin S, Kamal GM. The Determinants of Reproductive Change in Bangladesh: Success in a Challenging Environment. Washington, DC: World Bank; 1994 Joshi S, Schultz TP. Family planning as an investment in development: evaluation of a program’s consequences in Matlab, Bangladesh. Yale University Economic Growth Center Discussion Paper No. 951. New Haven: Yale University; 2007 Bongaarts J, Cleland J, Townsend J, Bertrand J, Das Gupta M. Family Planning Programs for the 21st Century: Rationale and Design. New York: Population Council; 2012 Bongaarts J. What Can Fertility Indicators Tell Us about Pronatalist Policy Options? Vienna Yearbook of Population Research. 2008: 39–56 Luci-Greulich A, Thévenon O. The impact of family policies on fertility trends in developed countries. Eur J Popul 2013;29(4): 387–416 Caldwell J, Caldwell P, McDonald P. Policy responses to low fertility and its consequences: a global survey. J Popul Res 2002;19:1–24 Gauthier A. The impact of family policies on fertility in industrialized countries: a review of the literature. Popul Res Policy Rev 2007;26:323–346 McDonald P. Low fertility and the state: the efficacy of policy. Popul Dev Rev 2006;32:485–510
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