With UN demographers more certain than ever that global population will reach between 10 and 12 billion by the end of the century, the challenge of building a sustainable future seems daunting. But according to Wolfgang Lutz, founding director of the Vienna-based Wittgenstein Center for Demography and Global Human Capital, these projections miss one crucial variable: increasing levels of education.

Through a groundbreaking, peer-review-style inquiry of over 500 experts, the Wittgenstein Center found that education, particularly female secondary education, is an important demographic variable that not only affects growth trajectories, but development paths and adaptive capacity to climate change.

Lutz and his colleagues determined that between the best and worst-case scenarios of future educational expansion, there’s a difference of more than 1 billion people in projected population growth by 2050 alone, and based on expected levels investment in education, global population will peak around 9.4 billion in the 2070s and decline to 9 billion by 2100.

Lutz, alongside William Butz, a co-editor and director of coordination and outreach at the Wittgenstein Center, unveiled the book that encapsulates much of their findings, World Population and Human Capital in the 21^st Century, at the Wilson Center on October 23.

The Education Dividend

Social scientists have long recognized a strong correlation between fertility decline, education, and socioeconomic development, but the Wittgenstein Center study is the first to demonstrate what Lutz called “functional causality” – that increases in societal levels of education lower total fertility rates and boost economies.

What demographers have labeled a “demographic dividend” – a window of increased economic productivity that can follow after a population stops growing rapidly – is in fact an education dividend, argues Lutz.

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“We can see that increases in education typically come before the decline in fertility, and so simultaneously trigger a fertility decline and increased productivity of women,” he explained. “What looks like a strong correlation between fertility decline and changing age composition as well as economic growth following seems to be education triggered.”

Education is a physiological process; “every learning experience changes our brains for the rest of our lives,” said Lutz. In aggregate, those who go to school have greatly enhanced cognitive skills, including the ability to plan more carefully, learn from mistakes, and avoid risky behavior. Along with the new employment opportunities that education creates, these changes lead to more people living stable, healthier lives, and planning to invest more resources in fewer children.

Girls’ secondary education, he explained, is particularly important; it endows young women with the ability to access information about contraception and healthy lifestyles, and with the income and confidence to pursue both, even in societies where their reproductive rights and decision-making abilities are not respected.

“There’s so much evidence that women who are classified to have an unmet need for contraception, a big reason for not using contraception is that their husbands or their extended family has objections,” said Lutz. “Well if the woman is empowered through education, she can more easily overcome these obstacles.”

Over time, through a process known as “demographic metabolism,” improvements among the youngest generations in primary and secondary education lead to higher educational attainment and lower fertility rates across societies, said Lutz.

Incorporating these ideas into global population projections yields more moderate forecasts than traditional models, since educational attainment, particularly among women, has increased substantially throughout much of sub-Saharan Africa.

The Wittgenstein demographers project that the percentage of African women of childbearing age with secondary education or higher will increase from 37 percent in 2010 to 68 percent in 2050. Thus, unlike the UN, they predict global population will stabilize by the end of the century, with two thirds of the 117 countries that have above-replacement-level fertility dipping below replacement level by 2060.

“This is a key advance,” said Scott Radloff, project director at PMA2020, a monitoring and evaluation project for efforts to expand access to family planning. “There’s a need to continue sharpening our estimates and expanding our thinking and this effort does just that.”

Human Capital Builds Adaptive Capacity

Data on education attainment is crucial not only to making more accurate population projections, but assessing prospects for development.

 “The societal level of human capital is a key driver of development, ranging from public health to economic growth, to quality of institutions and governance and democracy, and even adaptive capacity to climate change,” said Lutz. Improving education is also a development strategy that is fully consistent with individual empowerment and human rights, and is useful to wealthy countries, which are beginning to worry about economic stability in the face of aging, dwindling populations, said Radloff.

The benefits of investing in education are particularly noteworthy when it comes to climate change, said Butz. In conjunction with the research published in their book (already more than a thousand pages), the Wittgenstein Center wrote and commissioned 11 studies, published in a special issue of Ecology and Society last March, to explore the relationship between educational attainment and adaptive capacity.

Each study covered a different natural disaster and examined both vulnerabilities and responses at a variety of levels – individual, household, community, and national. Cumulatively, they demonstrate that education enhances resilience on each of these scales, said Butz.

Individuals who are better educated tend to avoid living in vulnerable areas, are less reliant on local natural resources for their livelihoods, and understand information on disaster and community risk better, said Butz. They also recover from traumatic stress more rapidly and are less likely to adopt coping strategies that reduce human capital investment, like taking their children out of school.

Billions will be spent on adaptation in the coming decades, the lion’s share of which is likely be allocated towards place-specific infrastructure. That may be a mistake, Butz said:

Our data suggests that some substantial part of that should instead be redirected to investment in human capital through schooling and through health which moves wherever people move and is shown to increase their resilience and increase their capacity to react.

A New Population Policy

“Improvement of projections is critical, but so is improvement of understanding,” said Jason Bremner, associate vice president and program director of population, health, and environment at the Population Reference Bureau.

To project population growth decades and even centuries out, demographers need to make assumptions about trends in fertility, mortality, and migration – and the polices that will guide them. “But most users [of these projections] are not demographers,” Bremner said, and are unaware of the massive investments in health and education that governments must make for even the middle of the road projections to occur.

To help leaders make sense of their findings, the Wittgenstein Center aligned their population projections with the Intergovernmental Panel on Climate Change’sshared socio-economic pathways – scenarios that describe possible social and ecological evolutions over the course of the next century.

They detail how policies enacted under each scenario (in which the world moves towards sustainability, business as usual, inequality, conflict, or technological innovation) shape fertility, mortality, and education trends, and in doing so, influence population size and societies’ adaptive and mitigative capacities.

Hopefully, said Lutz, population growth scenarios that are related to available policy options, rather than based on a series of opaque assumptions about the future, will prove more useful.

Demography is “a topic that is very close to our lives,” he said. “It is a very emotional thing – fear of population explosion, or equally, fear of population decline.” Public discourse around it greatly benefits from not only better scientific data, but scientists’ voices.

As scientists, the only thing we can do and must do is provide a well-founded, differentiated picture of what the scientific evidence tells us up to today and what are the reasonable, evidence-based assumptions we can make for the future.

What that evidence says, according to Lutz, is that education is more important – to population age structure and growth, to development, and climate change adaptation – than was previously understood.

“The main point,” he said, “is that national human resource management for sustainable development could be the main paradigm, the main rationale, of population policies in the 21st century.”

Event Resources:

• Friday Podcast With Wolfgang Lutz
• Photo Gallery

Sources: Global Environmental Change.

Drafted by Sarah Meyerhoff, edited by Schuyler Null.