Only when fertility levels begin to fall in conjunction with continued low mortality rates, does a population 'age', in the sense that population growth slows and the relative size of the adult population, especially the elderly age group, increases. In recent decades and throughout the world, decreasing birth rates and mortality rates have combined to increase dramatically the average age of populations and the number of elders in a population. In developed countries one person in ten is over 65 and in some countries it is twice that ratio.
In the market-economy countries this trend has reduced the potential long-term growth rate, lowered savings rates and increased the claim of pensions on private savings and budget revenues. It has therefore made productivity growth an increasingly important factor. The social implications are many. Post-retirement income needs to be ensured. Basic health care services need to be accessible. Health and nutritional education must be provided. Retirement institutions, personal care services for those at home, social supports, counselling and leisure-time services and activities must be made available. The care of the elderly has largely shifted from a family responsibility to one of the government. In many countries governmental structures have lagged behind these social realities.
The ageing of the world population raises critical economic, social and political questions also for the developing countries, where the transition from a currently youthful population to an aging one will occur much more rapidly than it has in more developed countries. The national capacity to look after old people in traditional ways is being seriously weakened as the percentage of aged population rises. This makes the development of new methods of care necessary.
Only in the past few decades has the attention of national societies and the world community been drawn to the social, economic, political and scientific questions raised by the phenomenon of aging on a massive scale. Previously, while individuals may have lived into advanced stages of life, their numbers and proportion in the total population were not high. The twentieth century, however, has witnessed in many regions of the world the control of perinatal and infant mortality, a decline in birth rates, improvements in nutrition, basic health care and the control of many infectious diseases. This combination of factors has resulted in an increasing number and proportion of persons surviving into the later stages of life.
In 2002, Italy had the highest population of seniors, with 18.1% of the country's population being made up of citizens aged 65 and over. Other countries with a high percentage of seniors include Sweden, Greece, Japan and Spain. The growth curve will hit other countries later. The number of senior citizens in Singapore is espected to rise by nearly 400% by 2030 with similar rises predicted also in Malaysia, Colombia, Costa Rica and the Philippines. There are expected to be 70-million people aged 65 and over in the US in 2030 - roughly double today's figures. It is also expected that the number of citizens aged 85 and upwards will reach roughly 8.5 million by 2030.
In 1996, life expectancy was 65 years, and was as high as 80 in some countries. Due to the combined fluctuations in fertility, life expectancy at birth, and mortality, the average age of the world's population is expected to increase dramatically within the next forty years. While total world population is expected to treble in the 75 years from 1950 to 2025, the population of the over-60s will show a five-fold increase and the over-80s will increase to seven times their present number. This means that one person in every seven will be over 60 years of age in 2025 compared with just one in every 12 in 1950. In 1950, there were only an estimated 214 million people over the age of 60 in the world. In 1985, there were approximately 415.6 million; by 2025, that number is expected to reach 1,121 million (nearly two-thirds of them in the developing world). Consequently, their weight is expected to increase from 8.5% to 13.7% of the global population, while the weight of children aged 0-14 is expected to shift inversely from 13.4% to 8.4% - indicating a marked aging of the world population.
An expected 23% of the population of developed countries and 14% of the developing regions is expected to be over 60 by the year 2025. The aging of populations will be most dramatic in the developing world where the over-60s are expected to increase nearly seven times between 1950 and 2025, when they will number 800 million. In Africa the number of persons over 60 is expected to grow by a factor of 4.4, from 22.9 million to 101.9 million, between 1980 and 2025 - a much larger increase than for the population as a whole. In 1985, the developing world held 55.4% of the over-60s, very similar to the figure for 1950; but by 2025, over 70% of the over-60s will live there. The number of over-60s in the developing world will increase fastest between 2000 and 2025, when countries like Bangladesh, Brazil, Mexico and Nigeria will see their over-60s increase by nearly 15 times. This carries implications for problems of age dependency and economic development already being encountered in 'aging' countries of the more developed regions.
In the industrialized world, the trend toward an intensification of the phenomenon in Europe seems particularly marked in the north, whose global population figure will diminish from 17.6 million to 17.3 million by 2025. According to ILO, in 1991 more than 13% of inhabitants were aged over-65 in Belgium, Denmark, Germany, Greece, Italy, Luxembourg, and the UK. By 2000, nearly one quarter of the German population will be aged over 60, compared with 20% in 1992. Aging populations also mean that people are growing old faster than children are being born to support them in their old age. In 1950, there were 19 people over 60 and 45 children under the age of 15 for every 100 adults aged 15-59. By 2025, there are expected to be 40 over-60s and only 35 children for every 100 active adults. There will be 270 million 'economically inactive' over-55-year olds in industrialized countries by 2020. That will mean 38 older dependents for every 100 workers; twice as many as in 1950. In the EEC/EU alone in the year 2025, the number of people over 65 years of age is expected to increase by 21 million while that of potentially active young people between 20 and 39 years is expected to decline by over 15 million. Sweden, for example, will lose more than 600,000 inhabitants while experiencing an increase of nearly 300,000 in the number of those over 65 years of age. In the UK there are 2.3 active workers per retiree, in France 2.5, in Austria 2, and in Italy 1 to 1.3. The 'dependency ratio' in eastern Asia is expected to double by 2025, when China will have one person over 60 for every three active adults. In 1995 Italy became the first industrialized country where the number of pensioners exceeds the number of workers.
In the over-65 age group, the oldest segment -- over 80 years of age -- needs the most care. It will continue to grow in relation to the other segments and to the whole population. In the EC, it is expected there will be more than 13 million persons in this age category in 2025, an increase of 4.3 million in 40 years. Addition welfare issues are raised by the increase in the numbers of the very old. In 1980 there were an estimated 34.2 million people over the age of 80, that number having risen by almost 16% to 39.7 million in 1985. Again, although the numbers of the very old in the developed world at present outnumber those in the developing countries, by 2025 it is expected that about 60% of all those over 80 years will live in the Third World.
As the population ages, an increase in the incidence of ailments that affect the aged is expected, namely in cancer, heart disease and stroke, diabetes, chronic diseases, rheumatism, senile dementia, osteoporosis, chronic bronchitis, emphysema, blindness and hearing loss.
In 1999, the European Commission recognized three dimensions of the challenge posed by ageing in the European Union. The most important of them was the fact that the average age of people at work was rising, while their numbers were declining in relation to those no longer at work, particularly those who had retired. In such a situation early retirement and similar solutions simply made the problem worse. Pressure on pension systems was another dimension of the challenge. How can one ensure a decent pension for the growing number of elderly people, when the number of those contributing to pension schemes is falling? The third dimension was the growing need for old age care and health care, not counting medical treatment.
In 1999, women accounted for nearly two-thirds of people over 65 in the EU. This posed special problems, given that many women have worked for either a short time or not at all, and can therefore find themselves facing financial problems in old age.
From a social point of view, there are growing differences among older people in terms of their income, family and housing situation, level of education - and health, of course. In some cases, the age brings with it the risk of poverty and social exclusion.