An age-old assumption
The idea that dependent older people represent a great demographic challenge of our age has been turned on its head.
Academics from the University of Edinburgh argue numbers have actually been falling in Britain and the ratio of working adults to dependent pensioners is improving.
The research questions an assumption behind arguments for health, social care and immigration policies.
The findings were published in the British Medical Journal.
"The extent, speed and effect of population ageing have all been exaggerated and we should not assume that it will strain health and social care systems," Professor John MacInnes and senior research fellow Jeroen Spijker write in the article 'Population Ageing: The timebomb that isn't?'
Healthier and fitter
The mistake people have been making, the paper suggests, is to assume that all pensioners are dependent and all working-age adults are workers.
They point out that, while it is true there are now more people over 65 in the UK than children under 15, rising life expectancy means older people are effectively "younger", healthier and fitter than previous generations.
Instead of simply looking at how old someone is, the research focuses on how long they might be expected to live.
"Many behaviours and attitudes (including those related to health) are more strongly linked to remaining life expectancy than to age," it says.
In 1841, life expectancy at birth was 40 years for males and 42 years for females.
By 1900 it was 52 and 57 and today it is 79 and 83. So the point at which we enter 'old age' has also been changing.
Equally, using age to define the adult working populations makes little sense, the authors suggest, because "there are more dependents of working age (9.5 million) than there are older people who do not work".
So they calculated an alternative measure, what they call "the real elderly dependency ratio", based on the sum of men and women with a remaining life expectancy of up to 15 years divided by the number of people in employment, irrespective of age.
Using this measure, the paper calculates that old-age dependency in the UK fell by one third over the past four decades - and is likely to stabilise close to its current level.
The measure suggests similar falls in many other countries.
"Our calculations show that - over the past four decades - the population far from ageing, has in fact been getting younger, with increasing numbers of people in work for every older person or child," the authors say.
"The different story of population ageing told by our real elderly dependency ratio has several important implications for health policy and clinical practice."
In policy terms, this analysis to one of the central challenges of an ageing population might be something of a game changer. Rather than seeing longevity itself as an expensive problem, focus could shift towards managing morbidity and remaining life expectancy.
The paper demands society rethink some of its assumptions about elderly dependency - drawing a distinction between the 'young old' and the 'old old', if you like.
The census in 2011 showed that 1.4 million people of state pension age in the UK were in employment - almost double what it was just two decades earlier. Of those aged between 65 and 74, 16% were economically active at the last count.
Just over half of all pensioners describe themselves as being in good health and, while demand for elderly care services is rising, the BMJ article suggests the key drivers in deciding the impact on care budgets will be medical knowledge and technology.