Tommy Bengtsson Population ageing, the shift in age distribution towards older ages, is of immense global concern. It is taking place to a varying degree all over the world, more in Europe and some Asian countries, less on the African continent. The worldwide share of people aged 65 years and above is predicted to increase from 7. 5% in 2005 to 16. 1% in 2050 (UN 2007, p. 11). The corresponding ?gures for developed countries are 15. 5 and 26. 2% and for developing countries 5. 5 and 14. 6%. While population ageing has been going on for some time in the developed world, and will continue to do so, most of the change is yet to come for the developing world. The change in developing countries, however, is going to be much faster than it has been in the developed world. For example, while it took more than 100 years in France and more than 80 years in Sweden for the population group aged 65 and above to increase from 7 to 14% of the population, the same change in Japan took place over a 25-year period (UN 2007, p. 13). The scenario for the future is very similar for most developing countries, including highly populated countries like China, India and Brazil. While the start and the speed differ, the shift in age structure towards older ages is a worldwide phenomenon, stressing the signi?cance of the concept global ageing.

Tommy Bengtsson is Professor of Economic History and Demography at Lund University. He is also Director of the Centre for Economics Demography, same university, since 2006. Bengtsson has in recent years been co-author and co-editor of several books released at internationally distinguished publishers (MIT Press, OUP and Springer), and one of which received a prize from the American Sociological Association as Outstanding Book on Asia 2005. He has also had several articles published in international and well-known journals applying peer-review selection, and is co-editor for a special publication series at MIT Press. His international publications include Population, Economy and Welfare in Sweden (Springer–Verlag 1994), Population and Economy (Oxford University Press 2000, 2nd ed. 2003), Life Under Pressure (MIT Press 2004), Living Standards in the Past (Oxford University Press 2005), and Kinship and Demographic Behaviour in the Past (Springer 2008).