Demographics is the study of the distribution and size of populations very significant in gerontology as the worlds population is ageing due to the transition from high birth and death rates to lower rates. Projections of the size and structure of future populations are regularly published by governmental agencies in most countries.
The whole population is growing and ageing – a worldwide phenomenon – but greatest percent increase will be in those over the age of 85. The demographic changes that are affecting society have been in progress for over a century, but its impacts on the rest of society are becoming more acute in recent times. The so called ‘baby boom’ generation which was born during the immediate post war period (1946-1964) of increased birth rates are now approaching retirement, leading to significant increases in the size of the older population. There is not only an increase in the total numbers in the older age groups, but also an increase in the proportion of the population in these age groups.
• currently, about 1 in 10 is aged over 60
• it is expected to be 1 in 5 by 2050
• growing at a rate of 2.4% annually
• fastest growing segment is the >80 years group
• in 1900, only 4% of population > 64yrs; in 2000 14%
• life expectancy in 1900 was 49.2yrs; in 1991 it was 75.7
• 70% of deaths occur after the age of 65
• number of older persons will double between the years 2000 and 2030
In the United Kingdom:
• 20% of the population is aged over 60; by 2043 it is expected to be >24%
in 1991 the median age was 32,in 1998 it was 34.8. In 2021, it is projected to be 41
12% of the population is > than 65 years. By 2051, it is projected to be 25%
• females usually live 4-10 years longer than males; more males are conceived
• several theories proposed – genetic; hormonal (eg oestrogen protects against heart disease); social and behavioural differences.
• older men are twice as likely to be married than older women
Maximum life span expectancy or potential – this is the survival potential of members of a species or population. This is usually determined by the biological features of the species/population – the oldest a human has lived is 120yrs (Louise Calment who lived in Paris), which most demographers assume to be the maximum. Average life expectancy is increasing increased prevalence of chronic diseases.
The economic consequences of the ageing population have received a lot of attention in the news media:
• increased costs for health care (as this has increased at a greater amount than an improvement in life expectancy would suggest, it raises issues of utilisation of health care services)
• increased costs for the provision of pensions/social welfare
• the social and economic problems associated with the ageing population are rapidly increasing
However, these may not necessarily be inevitable and may be sustainable if economic growth can provide the increased resources.
Public concern over these issues have, at times, characterised the older persons as greedy and self interested “inter-generational” warfare due to the transfer of societal resources from the young to old via taxation. Due to changes in the ratio of younger to older persons these debates will continue. In the USA, in 1994 the ratio of young to older was 5:1 – between 2030 and 2040, this is expected to be 3:1.