even zero population growth." Around the world The world's older population is growing dramatically. Asia and Africa are the two regions with a significant number of countries facing population ageing. Within 20 years, many countries in those regions will face a situation of the largest population cohort being those over 65 and the average age approaching 50. In 2100, according to research led by the University of Washington, 2.4 billion people will be over the age of 65, compared with 1.7 billion under the age of 20. The Oxford Institute of Population Ageing is an institution looking at global population ageing. Its research reveals that many of the views of global ageing are based on myths and that there will be considerable opportunities for the world as its population matures, as the Institute's director, Professor Sarah Harper, highlighted in her book Ageing Societies. Most of the developed countries now have sub-replacement fertility levels, and population growth now depends largely on immigration together with population momentum, which also arises from previous large generations now enjoying longer life expectancy. Of the roughly 150,000 people who die each day across the globe, about two thirds, 100,000 per day, die of age-related causes. In industrialised nations, that proportion is much higher and reaches 90%. Well-being and social policies The economic effects of an ageing population are considerable. Older people have higher accumulated savings per head than younger people but spend less on consumer goods. Depending on the age ranges at which the changes occur, an ageing population may thus result in lower interest rates and the economic benefits of lower inflation. Some economists in Japan see advantages in such changes, notably the opportunity to progress automation and technological development without causing unemployment, and emphasise a shift from GDP to personal well-being. However, population ageing also increases some categories of expenditure, including some met from public finances. The largest area of expenditure in many countries is now health care, whose cost is likely to increase dramatically as populations age. This would present governments with hard choices between higher taxes, including a possible reweighing of tax from earnings to consumption and a reduced government role in providing health care. However, recent studies in some countries demonstrate the dramatic rising costs of health care are more attributable to rising drug and doctor costs and the higher use of diagnostic testing by all age groups, not to the