1. Introduction
Population issues and population policies have evolved considerably between the 20th and the 21st centuries. Rapid global population growth, which appeared to run away in the second half of the 20th century and was framed as the central issue of population policy, has now slowed in terms of annual rates of growth. Undoubtedly, annual population increases in absolute numbers have remained substantial, as 87 million more people on average have been added to the world population every year between 1981 and 2020 [
1]. Nonetheless, zero population growth and “peak” population could possibly occur before the end of this century, although this point is being debated [
2]. Despite rapid population growth still occurring in sub-Saharan Africa and some other regions (mainly a few countries in the Middle East and parts of South Asia, e.g., Yemen, Afghanistan, Pakistan), most of the world’s population is now experiencing low fertility and, consequently, population aging [
1,
3]. The world is also becoming more and more urbanized. In addition, a host of new issues have emerged as well, such as climate change, new pandemics, international migration, and flows of refugees [
3]. Aside from a shift in focus, the overall framing of population policies has also changed, from demographically driven interventions to the affirmation of reproductive rights. Finally, feminist perspectives have also helped shape population policies [
4].
This article will first analyze how population issues in the 20th century differ from those in the 21st century, with a focus on the period from 1950 to 2020. Then, the article will examine two key issues: the discussions about whether to intervene on population trends, which evolved between the 20th and 21st centuries, and the debate about how to intervene on population trends, which also changed during this period. Finally, the article will chart the way forward and outline the key points of a new policy agenda. (Many elements of this article are taken from the recent book of J. F. May and J. A. Goldstone (Eds), International Handbook of Population Policies, Cham, CH: Springer, 2022.)
2. Population Issues in the 20th and the 21st Centuries
After World War II, a round of population censuses carried out in the 1950s highlighted the extremely rapid population growth in several countries, particularly in Asia [
3]. This triggered the fear among UN demographers and international policymakers that in some countries surging populations would outrun the growth in food supply and outrace the investment of capital per person, leading to declining income per head at best, and widespread starvation and social disorder at worst.
Table 1 presents some key demographic indicators for the major regions of the world in 1950 and 2020. The population has increased in all regions, but the annual rate of population growth has decreased everywhere, except in Africa. The total fertility rate has also decreased everywhere, although the decline has been slower in Africa.
According to the Population Division of the United Nations, global population growth reached an historical peak in the early 1960s, with an annual growth rate of 2.27%; in some South and Southeast Asian countries, such as Pakistan, Iran, Indonesia, and the Philippines, annual growth reached 2.5–3% [
1]. If those growth rates were sustained, global population was forecast to double in about 30 years, and to quadruple in about 60. At the time, global population growth was viewed as a major concern. Several influential publications—for instance, Paul Ehrlich’s The Population Bomb (1968) [
5] and the report The Limits to Growth of the Club of Rome (1972) [
6]—highlighted the danger of runaway population growth, anticipating the depletion of the world’s natural resources.
In 1974, the United Nations convened a World Population Conference in Bucharest, Romania, which, despite a lack of consensus on whether to intervene or not on population issues, adopted a World Population Plan of Action underlining the rights of couples to determine the number and spacing of their children [
4]. At around the same time, the Population Movement, which was funded mostly by U.S. foundations, started to launch family planning programs in Asia, Latin America, the Middle East, and sub-Saharan Africa. Over the next decades, voluntary fertility reduction programs helped countries such as India, Brazil, and Bangladesh to reduce their fertility levels to near or below replacement level [
7].
The overall result of these fertility declines was that the growth of the global population did not surge as rapidly as some feared, while increases in the output of foodstuffs and manufactured goods greatly outran population growth, reducing poverty (in percentages but not in absolute numbers), and raising real incomes in most parts of the globe [
3]. Regarding foodstuffs, it is interesting to note that, historically, global food production has more than kept pace with past population increases; indeed, obesity has become a global concern.
Unfortunately, these past advances might not be sustainable. Yields of major staples have recently plateaued, and the aquifers supplying major breadbasket regions are being drained. The severe droughts and floods in recent years that have destroyed crops and cut yields across Asia, Europe, and the Americas may become a “new normal.” The Russian invasion of Ukraine in February 2022 has restricted supplies of cereals and fertilizers, which could lead to serious famine conditions re-emerging in some regions. The trade disruptions in Russia and Ukraine temporarily pushed energy and food prices to levels that are impoverishing many in both rich and poor countries.
Moreover, if a growing global population continues to burn fossil fuels and consume meat at an ever-increasing rate, our ability to provide a sound standard of living to all people will be imperiled. Nonetheless, poverty and food crises are becoming more concentrated, due to population growth and urbanization continuing mainly in low-income countries, especially in Africa, the Middle East, South Asia, and parts of Latin America, while East Asia, Europe, and North America are facing population stabilization or decline. Future levels of poverty, food shortages, and even global population growth will be determined to such an extent by fertility patterns in Africa and South Asia that these regions should be the focus of our attention [
3].
The decline of fertility and the slowing down of global population growth, though a clear trend, may have led some observers to become overly sanguine about world population growth ending in the 21st century [
2]. Although fertility levels have decreased in many countries, the persistent high fertility in Africa (including in sub-Saharan African countries, where the decline in fertility started about 30 years later than in other less developed countries [
8]), a portion of the Middle East, and parts of South Asia has perhaps been underestimated. Furthermore, history suggests that the current UN projections of rapid fertility decline might be too optimistic. If high fertility persists in regions that will soon have roughly one-half of the world’s population—namely Africa and South and Southeast Asia—global population growth may continue longer than expected.
Notwithstanding persistent high fertility in parts of the world, the overall size and growth of the global population arouses less concern than in the 1970s, because population growth is cresting or may soon be declining in many countries, unless bolstered by immigration [
3]. Population growth might perhaps cease before the end of the 21st century, although, as mentioned above, the timing of the zero-population growth and subsequent depopulation is being debated [
2]. However, the distribution and composition of the world’s population is now changing in ways that pose new challenges. Specifically, in rich countries and emerging economies, declining fertility has fallen to, and stabilized at, well below replacement levels—levels so low that they were not foreseen by demographers and policymakers. This has put dozens of countries, especially in Europe and East Asia, on course for depopulation, despite immigration inflows [
3]. Another consequence has been declines in the labor force and surges in the elderly population, accelerating a host of labor market and fiscal pressures. At the same time, in many of the world’s poorest countries, especially in sub-Saharan Africa, fertility has remained at a high level, above four children per woman. This has raised the puzzle of why fertility remains high in these countries, and of explaining the pervasive preferences of couples for large family sizes [
8]. Sustained high fertility in these countries has resulted in extremely young and fast-growing populations, which hamper advances in education and income per person and may jeopardize social and political stability [
3]. In the middle, many middle-income countries that have successfully reduced fertility, such as India and Indonesia, are favorably positioned to enjoy a first demographic dividend to promote their development [
8,
9]. This dividend is an economic surplus that may occur when, due to declining fertility, the population age structure changes, with relatively more people in the labor force and relatively fewer dependents, especially young dependents (a second demographic dividend may also be available when the benefits of the first dividend have been saved and invested, which is the current situation in some East Asian countries) [
8]. However, to take advantage of the first demographic dividend, these countries will need to implement education, investment, and health programs to take advantage of this favorable demographic conjunction while it lasts [
9].
Another novelty is that rapid urbanization and very large cities, which throughout most of human history were found mainly in the world’s richest societies, are now instead arising in some of the world’s poorest countries in sub-Saharan Africa and South Asia [
10]. How these megacities will be supported and governed in countries with low resource levels, even whether rapid urbanization itself should be discouraged, is a pressing issue.
The combination of population aging, shrinking populations in upper-middle- and high-income countries, and youthful and fast-growing populations in several lower-income countries has added impetus to global migration, which is also being stimulated by climate change and violent conflicts. While global migration seems to be a logical response to the trends in the distribution of global population, in fact the unpredictable nature of migration surges and the shift in migration patterns from nearby and familiar to more distant and culturally dissimilar sources have led to a striking anti-immigrant backlash in many countries of Europe, Asia, the Americas, and even within Africa [
11]. In most developed countries, the failure to engage with migration as a quantitative issue, rather than one of race and xenophobia, has added to the acrimony of the debate on migration.
As many demographers have pointed out, sufficient immigration to prevent population aging is unsustainable and would carry far greater challenges than population aging itself. In addition, should the surplus population of high-fertility countries emigrate, this would increase annual migration flows by an order of magnitude and vastly overwhelm the absorptive capacity of receiving nations [
12]. Currently, sending and receiving countries are scrambling to devise policies to attain their migration goals. The problems that would be generated by massive immigration flows mean that countries will need to solve their problems of high fertility, low fertility, and/or population aging without depending on migration as the sole solution.
The emergence of climate change concerns and the new pandemics (e.g., COVID-19) have also changed population issues since the end of the 20th century. Climate change may trigger flows of environmental refugees. The COVID-19 pandemic will also have an impact on mortality, fertility, and migration trends, although it is too early to measure the consequences of this major health crisis [
13].
To conclude, all these changes in population issues between the 20th and the 21st centuries—from high to below replacement fertility, from young to rapidly aging populations, and from rural to urban settings—have brought a host of new issues that population policies will need to address.
3. Discussions about Whether to Intervene on Population Trends
Since World War II, discussions on population issues have been dominated by one question: to intervene or not to intervene? Should public policies attempt to decrease high fertility levels and accelerate the demographic transition? Or should developmental efforts focus on increasing the economy, so the economic surplus would satisfy more people? Proponents of economic growth (most countries in the South) dismissed supporters of fertility reduction and family planning programs (most industrialized countries in the North, in particular the U.S. and its allies) as unwanted meddlers.
This debate reached high fever pitch at the first World Population Conference organized in Bucharest in 1974 [
7,
14]. “Development is the best contraceptive,” claimed Mr. Karan Singh, the head of the Indian delegation at Bucharest (he later reversed his opinion) [
7]. Anti-colonialists and anti-imperialists expressed their opposition to the fertility reduction strategy advocated by the industrialized countries. The Soviets and the Chinese reiterated the Marxist position, namely that rapid population growth is a consequence and not a cause of underdevelopment (although China itself had started a strong family planning program under the slogan “later, longer, fewer” in the early 1970s) [
7]. No resolution was achieved in the debate about economic growth vs. family planning, and the U.S. and its allies were eventually outnumbered. Most countries were not ready to embark on state-led programs aiming to lower fertility, and the concept of “population control” itself became a dirty word. To sum up, the Global South wanted massive aid, not contraceptives [
14].
Ten years after Bucharest, at the International Population Conference in Mexico City in 1984, the tables had turned [
4,
15]. Many poor countries were struggling to keep pace with their population growth, and were more willing to recognize family planning as a vital instrument to enhance economic development. In contrast, under the Reagan Administration, the U.S. reversed its longstanding position that rapid population growth was a barrier to socioeconomic development. The U.S. Administration claimed that population growth was neutral for economic development, and this opinion was reiterated in a report of the U.S. Academy of Sciences [
16]. Several U.S. scholars supported this position, for instance Julian Simon in The Ultimate Resource (1981, 1996) [
17] and Ben Wattenberg in his books about the birth dearth and population aging [
18]. The decision to downplay any costs of population growth coalesced with the pro-life and anti-abortion platform of the U.S. Republican Party.
Other events also contributed to marginalizing population issues within the international development agenda. Efforts to mitigate the HIV/AIDS pandemic diverted funds from family planning programs. The emergence of the environmental movement pushed aside discussions of population issues [
19]. Feminist and human rights groups, which became active in the late 1980s, reframed the only desirable population interventions as those that supported family health and rights, especially for women.
At the time of the 1994 International Conference on Population and Development (ICPD) in Cairo (this was the last world population conference) [
4], these new groups, lobbies, and coalitions had gained a preeminent position in the global debates on population issues. Emphasis on “population control” had disappeared. Demographic targets had been abandoned in favor of reproductive health and rights. The so-called Cairo Agenda promoted individual choices and women’s empowerment. While the broad Cairo Agenda has indeed favored women’s empowerment, it also lessened to some extent the focus on family planning programs. The U.S. leadership on population issues, asserted through the U.S. Agency for International Development (USAID), had waned as well [
14]. Population issues were not prioritized in the Millennium Development Goals (2000–2015), although a family planning element (Target 5b) was added in 2005. Finally, the Sustainable Development Goals (2015–2030) include family planning access as one element under the goals for universal access to sexual and reproductive health and gender equality, but these concerns are hardly prioritized. The SDG framework is broad and covers all sectors of socioeconomic development (see
https://sdgs.un.org/goals) (accessed on 6 June 2023). The SDGs have 17 goals and 169 targets to monitor the implementation of the goals. The SDGs 17 goals are: no poverty; zero hunger; good health and well-being; quality education; gender equality; clean water and sanitation; affordable and clean energy; decent work and economic growth; industry, innovation, and infrastructure; reduced inequalities; sustainable cities and communities; responsible consumption and production; climate action; life below water; life on land; peace, justice, and strong institutions; and partnerships for the goals. The only vigorous efforts to promote family planning in recent years have been spearheaded by the Bill & Melinda Gates Foundation, under the FP2020 and FP2030 initiatives, as well as some other U.S. and European donors.
4. Discussions about How to Intervene on Population Trends
For much of the second half of the 20th century, when many countries experienced high fertility and rapid population growth, global population challenges were defined primarily in quantitative terms. Population policies thus focused on reducing fertility, and the major issues were whether that reduction could be obtained simply by providing and promoting family planning services, trusting in voluntary acceptance of fertility reduction, or whether more vigorous measures (e.g., India’s sterilization campaigns during the Emergency in 1975–77 and China’s One-Child policy of 1979) would be needed [
7].
To a large extent, this contest has now been settled by the fact that voluntary fertility reduction has been far more widespread and rapid than was anticipated by demographers and policymakers, while coercive efforts to limit fertility have rightfully been condemned as abuses of human rights. However, while in many countries voluntary fertility reduction has been dramatic, in other countries it has remained modest, and it could be argued that in the latter, family planning programs could have been more efficient if they had addressed the cultural norms that sustain restricted women’s roles, early marriage, and frequent childbearing. Thus, after a history of policies that focused mainly on promoting contraception to reduce fertility, population policies have now turned to finding ways to promote women’s rights and cultural norms that enhance voluntary fertility reduction in countries that continue to have high fertility (above three children per woman).
Meanwhile, in countries that have very low fertility (below 1.8 children per woman), many governments are rolling out incentives to encourage more childbearing. And while migration has always been subject to policies to control entry at the border, in recent years, policymakers have given more attention to the integration of migrants in host societies, to shaping the composition of the migrant population, and to coping with ever-larger numbers of humanitarian refugees.
As mentioned above, the 1974 Bucharest World Population Conference rejected the idea of Western donors imposing targets for fertility and population growth in developing countries. Yet the Conference also marked a moment when developing countries themselves began to design and implement their own population policies. The countries at the Bucharest Conference had prepared a World Population Plan of Action, which stipulated that all individuals and couples had the right to determine freely and responsibly the number and spacing of their children and should be provided access to the information and means to do so [
4]. Over the next two decades, numerous countries in Asia and Latin America implemented family planning programs, and attempts were made to introduce family planning in sub-Saharan Africa. In 1979, China enacted its One-Child policy, which was a more rigid and restrictive expansion of its previous “later, longer, fewer” family planning program. In all regions, countries adopted formal population policies to reduce fertility and/or encouraged NGOs to expand access to family planning services. The International Planned Parenthood Federation (IPPF), created in 1952 (the same year India adopted its first Population Policy), was particularly helpful in nurturing family planning institutions in the Global South [
7]. These efforts helped expand public health services as well. The U.S. Agency for International Development (USAID) was by far the largest donor, along with major contributions from the United Nations Population Fund (UNFPA), the World Bank, and European donors. The necessary data to monitor these programs were collected under the World Fertility Survey (WFS) and, thereafter, the Demographic and Health Survey (DHS) program essentially funded by USAID, and the Multiple Indicator Cluster Surveys (MICS) conducted under the auspices of UNICEF [
20]. The period from the early 1970s to 1994 could be seen as the heyday of family planning efforts, although in some countries the zeal for reducing fertility led to serious human rights violations.
Many of these family planning programs were very successful, leading to reductions in fertility of three or more children per woman within 20 years. The most successful programs actively worked to modify prevailing cultural norms alongside providing accessible and quality reproductive health services. Some programs even managed to bring fertility down to the replacement level, about 2.1 children per woman [
21]. In this respect, the case of the Islamic Republic of Iran shows that family planning programs can succeed in very diverse environments. Between 1986 and 1999, the total fertility rate of Iran decreased from 6.01 to 2.10, a decline of nearly 4 children per woman in just 13 years [
1]. The exception was sub-Saharan Africa: initial efforts to introduce family planning programs were arduous [
22] and, as mentioned above, the region started its fertility decline about 30 years after most other less developed countries [
8]. Indeed, sub-Saharan Africa would benefit from faster and significant fertility declines in order to capture a first demographic dividend [
9].
The major lesson learned is that the most acceptable and effective policies to reduce fertility were multi-faceted and integrated strategies that included support for education, human capital formation, the empowerment of women, governments’ and cultural leaders’ encouragement of smaller families, and the improvement of women’s and reproductive health, especially in rural areas. However, these worked best where nuclear and stem family structures shifted focus from the goal of producing large families to the goals of improving human capital formation and producing more economically productive women and children. In settings where extended kin structures maintained strong support and demands on women to produce larger families, fertility has remained high. Thus, if sub-Saharan Africa’s continued high fertility is to change, the most important factor will be changing the cultural norms for high desired family size and valuing women based on their fertility.
However, as fewer countries remain concerned about high fertility, more and more countries are now facing a very different problem, i.e., below-replacement fertility levels. The shift from growing and younger to stable and older populations will require fresh policy thinking. Trying to bring back high fertility levels by pro-natalist policies has been shown to be ineffective. That means countries must plan for a permanent adjustment to older, stable, or decreasing populations. Currently, in rich countries, people retire with 20–30 years of life expectancy, usually with incomes and medical care supported by transfer payments from younger taxpayers. Increasing the ratio of retirees to taxpayers necessitates adjustments in the funding model. New policies will need to include, inter alia, changes in retirement toward phased reductions in work, the promotion of more savings for retirement, and the reform of medical care to save money by encouraging preventive healthy lifestyles.
Finally, with respect to immigration, countries have adopted very different policies. Canada and Australia have been in favor of a high volume but somewhat planned immigration regime. Japan has greatly increased its provision of multi-year temporary work permits, while South Korea has eased the provisions for non-Koreans to become citizens (especially by marriage, as the number of Korean men marrying women from other Asian countries has dramatically increased in recent years). By contrast, some conservative political constituencies in the U.S. are currently tempted to embrace the Hungarian model of aiming for zero immigration, with all jobs carried out by native-born workers. Others argue that maintaining or even increasing immigration in the U.S. (and Japan, for example)—whether by temporary work visas or expanded avenues for permanent settlement—appear necessary to meet short-term labor shortages in high-demand areas like construction, agriculture and food processing, care for the elderly, and other labor-intensive services, while also providing a limited cushioning effect for the transition to later retirement and lower health-care spending [
23]. However, higher immigration to meet labor needs must also be balanced against the costs of additional public infrastructure for an expanded population, the environmental impact of a larger population, and the issues that arise in the cultural assimilation of larger numbers of foreign-born workers. In any event, as low-fertility countries face a situation in which immigration will have a substantial impact on whether, and how fast, their population grows, and on their age structure, the complexities of immigration will require a thoughtful balancing of diverse needs and claims.
6. Conclusions
Population issues have changed significantly during the past 70 years. World populations have shifted from rapid growth to slower growth in most countries and population structures have changed as well, ushering in the era of population aging. The world has also become more urbanized and international migration flows have increased steadily, despite the Great Recession in 2008. Climate change has become a major concern since the 1990s and new pandemics have disrupted the socioeconomic fabric of countries around the world.
Population interventions and population policies have been forced to adapt to these changes. In the 1970s, the period of rapid population growth, policies were driven by quantitative targets. Some countries, such as China and India, even implemented coercive population interventions to decrease fertility. Gradually, however, the dominant demographic paradigm was abandoned in favor of women’s and reproductive rights. In this respect, the 1994 International Conference on Population and Development (ICPD) was a sea-change event. The new policies were also shaped by the feminist agenda. Finally, emerging concerns around climate change and the new pandemics contributed to modify the population policy debate as well.
We are hopeful that a new policy agenda is emerging, with an emphasis on the prioritization of policy interventions, policy consensus building, the selection of priority constituencies, the institutionalization and funding of policies, and the promotion of evidence-based and research-driven policies. In addition, in order to adapt their interventions to local contexts, population policies will need to be holistic, to promote integrated approaches, and to align with international development frameworks.