News Release

New book looks at the future of population and migration

Book Announcement

International Institute for Applied Systems Analysis

A new book from IIASA and the European Commission's Joint Research Centre (JRC) examines potential future scenarios on population trends across the world, taking into account migration, fertility, mortality, education, and labor force participation.

The book, Demographic and human capital scenarios for the 21st century, is the work of the Centre of Expertise on Population and Migration (CEPAM) a collaboration between IIASA's World Population Program and the JRC. The CEPAM partnership was launched to provide comprehensive assessments of the drivers of possible future migration to Europe and study the implications of alternative future migration scenarios that could help to inform European policies from 2019 onwards. The book presents an essential background study for that work. It also serves as an update to a previous book, World Population and Human Capital in the Twenty-First Century, published in 2014.

When fertility levels are low, as is being seen in Europe at the moment, international migration becomes the main factor influencing population growth. However, in terms of economic growth, the size of the labor force and productivity matter more. Previous demographic assessments have only considered age and sex in population trends, while this new study also factored in educational attainment and labor force participation for EU member states.

The book looks at the population outcomes for 201 different countries, based on three different migration scenarios in addition to different fertility, mortality, and education scenarios. The 'medium' scenario assumes that migration rates will remain similar to the average level observed for each country from 1960-2015. The 'double migration' scenario assumes twice the average level of in- and out- migration rates. The 'zero migration' scenario assumes no migration. The editors say that these "naïve" scenarios serve as benchmarks to understand how migration affects population, rather than realistic forecasts.

"Migration should be seen as an integral part of population dynamics. This is why this volume considers it in the context of alternative possible scenarios for all countries of the world over the rest of this century," says IIASA World Population Program Director Wolfgang Lutz.

For example, in the medium scenario, world population would continue to increase until 2070-80, reaching 9.8 billion before beginning to decrease. The increase is higher than in the 2014 book largely due to a faster decline in child mortality in Africa. An alternative scenario assuming rapid social development and in particular better levels of education of women would lower fertility rates, with a peak population of 8.9 billion reached in 2055-60. Stalled social development and lower levels of education result in higher fertility rates and the population continuing to climb over the century, reaching 13.4 billion in 2100.

Different areas of the world, however, will differ. In the European Union, under the medium scenario, population will marginally increase to around 512 million people by 2035, largely due to immigration. After that there will be a decline as fertility rates are low, with significant aging seen. However, the available labor force does not necessarily shrink if female participation rises.

Meanwhile, in Sub-Saharan Africa, the population under the medium scenario is likely to double by 2060, to around 2.2 billion people. With stalled social development and a lack of expansion of schooling, this could even rise to 2.7 billion. This in turn would lead to widespread poverty and high vulnerability to climate change with serious implications for potential emigration.

The scenarios developed will also help policymakers facing a broad range of challenges from the economic consequences of population aging to setting development priorities in Africa.

The editors say that the results of the CEPAM studies show that within certain bounds, future trends in population are not a given, and can still be influenced by policies in the longer term. In the short term, it is migration that can most easily be influenced by policies.



Lutz L, Goujon A, Samir KC, Stonawski M, Stilianakis N eds. (2018) Demographic and human capital scenarios for the 21st century. Luxembourg: Publications Office of the European Union []

More information

Lutz W, Butz WP, and Samir KC. (2014) World Population and Human Capital in the Twenty-First Century. UK: Oxford University Press []


Wolfgang Lutz
Program Director
World Population
Tel: +43(0) 2236 807 294

Helen Tunnicliffe
IIASA Press Office
Tel: +43 2236 807 316
Mob: +43 676 83 807 316

About IIASA:

The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policymakers to shape the future of our changing world. IIASA is independent and funded by prestigious research funding agencies in Africa, the Americas, Asia, and Europe.

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