"Getting old before getting rich is one of the biggest medium-term structural challenges in developing Asia and Latin America," said Samantha Amerasinghe, an economist at StanChart, who added that Brazil was in the same boat.
"Middle-income countries are concerned about this [because] it might inhibit their ability to join the group of high-income developed countries. Unfavourable demographics could lower potential GDP growth rates and hamper development."
Central to concerns over the greying of populations in much of East Asia and parts of Southeast Asia are that these countries are not simply copying the demographic patterns of the developed world, which may be better placed to cope with an ageing population.
Not only are some Asian countries greying at lower income levels, they are also doing so at a far faster rate than the west did, meaning they are on track to overtake the west in the ageing stakes.
For instance, it took France 115 years to double the share of its population aged 65-plus from 7 to 14 per cent, Sweden 85 years, Australia 73 years and the US 69 years.
In contrast, South Korea is expected to see the same transformation in just 18 years, Thailand in 21 years and China in 23, as the first chart shows.
This dramatic transition is partly driven by falling fertility rates, which StanChart estimates will fall to two children per woman across Asia by 2025-30, compared with 5.1 children as recently as 1970-75.
Fertility rates have fallen to below 1.4 in Hong Kong, South Korea, Japan and Singapore, 1.5 in Thailand and 1.6 in China, all below the replacement rate, while even in India they are down to 2.3 (though we should not lose sight of the bigger picture, with the UN forecasting that the global population will surge from an estimated 7.4bn, as of August, to 11.2bn by 2100, driven by a near-quadrupling in Africa).
At the same time, life expectancy in Asia has also been rising rapidly, from 42 in the 1950s to 72 now, a faster rate than in either the developed world or the rest of the developing world.
These factors are likely to mean that the proportion of pensioners in the population of several Asian countries will outstrip that of many developed countries in the coming decades, particularly if the UN is correct in its forecast that fertility rates in Europe are set to rise from 1.6 to 1.8 children per woman.
By 2050, the UN forecasts that 35.1 per cent of the South Korean population will be aged 65-plus, up from 13.1 per cent in 2015, ahead of the 33.9 per cent of Singapore. Thailand's share of the elderly is projected to have surged from 10.5 per cent to 30.1 per cent by then, and that of China from 9.6 per cent to 27.6 per cent.
By 2050, all four of these countries are expected to have a higher share of over-65s than in developed countries such as Canada, France, the UK, Australia and the US, although Japan will still remain top of the pile, as the second chart shows.
"The next phase of global ageing will be driven by rapid ageing in key Asian economies," said Ms Amerasinghe. "According to UN forecasts, Korea, Singapore and Hong Kong will see the biggest rises in the share of seniors in their populations, despite already having relatively old populations.
"Thailand and China will also be among the most rapidly greying societies, becoming 'aged' [defined as having more than 14 per cent of their population aged 65-plus] by the middle of the next decade. They will both become 'hyper-aged' by 2035, with 21 per cent or more of their population 65-plus. This would be only five years after Canada, the UK and the US become hyper-aged."
In terms of absolute numbers, the impact could be greater still: even in 2015, China had 131m seniors, more than the combined tally in Japan, Italy and Germany, the world's three oldest major countries.
The unusually rapid ageing of several Asian countries is also likely to be reflected in their labour forces, with the working-age population starting to decline in China, Hong Kong and Taiwan before 2020, South Korea and Thailand following suit between 2020 and 2025, and Singapore soon after.
In contrast, the labour force in developed world countries such as Australia and the US is expected to continue rising until at least 2030, even if Japan's will be contracting, as the third chart shows.
This may be particularly problematic for the likes of China. "Smaller and more open economies such as Hong Kong and Singapore could counter the effects of ageing by importing labour," said Ms Amerasinghe.
"This is more difficult for larger economies, most notably China, given that it has the world's largest population. Immigration is also a sensitive issue in the region, as in other parts of the world."
China does ably demonstrate one of the options available to policymakers to tackle a declining workforce, however.
The official pension age in urban areas is just 50 for blue-collar women, 55 for white-collar women and 60 for men, significantly lower than in most western countries. This is despite China's life expectancy of 76 (74.8 for men, 77.3 for women) only being about three years lower than the western average.
StanChart says that China is likely to announce plans to reform its pension system later this year. It calculates that if Beijing raises the retirement age by a few months a year, so that it reaches 70 by 2025, then its demographics would be as strong as in 2010 for several decades to come, as depicted in the final chart.
In July, Singapore is due to raise its re-employment age. Although the retirement age is 62, companies must offer re-employment to eligible workers up to 65. This is due to be increased to 67.
Ms Amerasinghe argued that Seoul also had scope to raise its pension age, given that "Koreans typically retire from full-time corporate jobs in their mid-50s".
Taiwan may have options of its own, given that its "highly regarded social benefits and retirement schemes are often cited as the reason for the island's earlier-than-normal retirement age". Those working in the industrial and services sectors retired at an average age of 58.1 in 2015, significantly below the mandatory retirement age of 65.
Without reform, StanChart estimates that, in China, pension contributions would eventually have to rise to 50 per cent of earnings to ensure the long-term viability of the public pension system, with comparable figures of 40 per cent for Vietnam and almost 30 per cent in Thailand.
Other policy options include measures to raise the female employment rate, although this is already higher in China and Thailand than in most western countries, and to raise the fertility rate, although such schemes in Japan and South Korea have had "very little success".
One oddity unveiled by Standard Chartered's research is that the so-called "life cycle hypothesis" of consumption does not appear to stand up in most Asian countries.
In the west, the standard model is that people save money during their working lives then draw this down in retirement. In much of Asia, retirees do not seem to draw down their savings in this manner.
"Per capita private savings for Japan, India, the Philippines, Taiwan and Korea do decline but later than would be expected under the LCH. Only in Indonesia is there dissaving," Ms Amerasinghe said.
One explanation is that "asset income remains significantly more positive than expected", reducing the need to run down savings.
In addition, Asian retirees appear to be motivated by a desire to leave bequests for the next generation. Precautionary savings are also likely to be important, given the weakness of public pension funds and healthcare systems in many countries.
The downside of this is that consumption could fall as the share of pensioners in a country's population rises.
However, given the sheer rise in the likely size of China's 65-plus population by 2030, StanChart forecasts that consumption by this cohort will jump to $2.8tn a year by then, from just $400bn today.
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Copyright The Financial Times Limited 2017
