Population and Human Capital Projections integrated with SSPs

The latest set of science-based population projections by age, sex, and level of educational attainment for all countries of the world up to the year 2100 were published in 2014.

© Xiye_Dreamstime.com

© Xiye_Dreamstime.com

The production of new science-based population projections by age, sex, and level of educational attainment for all countries of the world with the time horizon of 2060, and extensions to 2100 have been at the heart of the World Population Program’s research over the last 5 years. The results are presented in the Oxford University Press volume World Population and Human Capital in the Twenty-First Century (eds. W. Lutz, W.P. Butz, S. KC).

The first set of numerical projections scenarios was produced by the IIASA demographers in the late eighties, while in 1996 IIASA was the first to produce global level probabilistic population projections (Lutz et al. 1997). The new global population projections significantly extend the state of the art by advancing two key priorities of the IIASA tradition: first, it substantially broadens the basis for incorporating into population projections the best substantive knowledge available in the international scientific community through the systematic involvement of more than 500 population experts around the world, and second, it explicitly and systematically incorporates population heterogeneity by level of education, thereby illustrating how educational attainment can and should be routinely added to age and sex as a third demographic dimension.

These new global population projections combine statistical models with expert judgment about the validity of alternative arguments that matter for future trends and with the synthesizing assessments of meta-expert meetings. The outcome of this process in terms of assumptions for overall total fertility rate, life expectancy at birth, and future migration was combined with a careful analysis of historical patterns of educational expansion which led to a statistical model for the formulation of the future educational attainment scenarios at the level of individual countries by POP’s interdisciplinary group (KC et al. 2010).

This process of producing a new set of world population projections went in tandem with the definition of the next generation of IPCC related scenarios that should capture both the socioeconomic challenges to climate change mitigation and adaptation. Called “Shared Socioeconomic Pathways” (SSPs), these new scenarios were developed by environmental and economic modelers from around the world through the use of alternative narrative storylines (KC & Lutz 2014). The demographic part of these scenarios was produced by IIASA’s World Population Program in collaboration with other Wittgenstein Centre demographers. 

While the previous generation of SRES Scenarios (Nakicenovic et al. 2000) only included total population size as the sole social indicator which largely served as scaling parameter for calculating per capita indicators, the new SSPs cover the global social trends in a much richer and much more relevant way by giving the full age, sex and education structure for every point in time and every country according to the SSP narratives. In this sense it has been called the “human core of the SSPs”.

All the described work is comprehensively reflected in the Oxford University Press book on World Population and Human Capital in the Twenty-First Century. The book presents and discusses the science of what is known about the drivers of fertility, mortality, migration and education in different parts of the world and what this knowledge implies for the course of population and human capital over the rest of the century. Specifically, the authors attempted to illustrate how the population future looks different when education is systematically added as a core demographic dimension.

This book also addresses systematically and quantitatively the role of educational attainment in global population trends and models. Six background chapters summarize past trends in fertility, mortality, migration and education; examine relevant theories and identify key determining factors; and set the assumptions that are subsequently translated into alternative scenario projections to 2100. These assumptions derive from a global survey of hundreds of experts and five expert meetings on as many continents. Another chapter details their translation into multi-dimensional projections by age, sex and level of education. The book’s final chapters analyze the results, emphasizing alternative trends in human capital, new ways of studying ageing and the quantification of alternative population and education pathways in the context of global sustainable development. An appendix and associated web link present detailed results for all countries.

The funding for this ambitious project comes from the European Research Council (ERC) Advanced Grant (“Forecasting Societies Adaptive Capacities to Climate Change” – FutureSoc) that was awarded to the POP director Wolfgang Lutz in 2009 and is carried out by IIASA in close collaboration with the other partners of the Wittgenstein Center for Demography and Global Human Capital (IIASA, VID/ÖAW, WU) and many colleagues around the world. 

Print this page

Last edited: 20 November 2014


Wolfgang Lutz

Program Director

World Population

T +43(0) 2236 807 294


Samir K.C.

Project Leader

World Population

T +43(0) 2236 807 424


Executive Summary: World Population & Human Capital in the Twenty-first Century

Wittgenstein Centre Data Explorer

International Institute for Applied Systems Analysis (IIASA)
Schlossplatz 1, A-2361 Laxenburg, Austria
Phone: (+43 2236) 807 0 Fax:(+43 2236) 71 313