The evolution of old-age to working-age ratios depends on mortality rates, fertility rates and migration. Both the Asian economies and OECD countries have seen prolonged increases in life expectancy that most analysts project to continue, implying an increasing number of older people and most likely of pensioners too.

Currently, the demographically oldest Asian economy is Hong Kong (China), with an old-age to working-age ratio equal to 36.0 (meaning 36.0 individuals aged 65 and over for 100 persons of working age defined as 20 to 64) (Table 3.2). China, Sri Lanka and Thailand are the only other economies with an old-age to working-age ratio above 20. By 2054, the old-age to working-age ratio is expected to reach more than 50 in China (64.2), Hong Kong (China) (117.1), Singapore (51.0) and Thailand (56.7).

By contrast, all the other economies are currently between 10 and 20, except for Pakistan (8.8) and the Philippines (9.7). In the second half of this century both of these countries are expected to remain considerably younger than the other economies, at 12.5 in Pakistan and 19.9 in the Philippines, with India and Indonesia being next at around 27. By 2084, the old-age ratio will only increase to 22.8 in Pakistan, nearly 20 below any other economy.

For the OECD there are 33 individuals aged 65 and over for every 100 persons of working age (ages 20 to 64) on average while there were only about 21 30 years ago. Population ageing has been accelerating as this average old-age to working-age demographic ratio – computed by keeping age thresholds constant – is projected to reach 55 over the next 30 years.

Four Anglo-Saxon OECD countries – Australia, Canada, New Zealand and the United States – have relatively low old-age ratios, around 30. This is partly due to inward migration of workers and – except for Canada – to comparatively high fertility rates just below replacement level in recent decades.

For the OECD, the increase in the old-age to working-age ratio is projected to continue according to the medium forecast of United Nations Populations Prospects, from 32.6 in 2024 to 55.2 in 2054 and 67.7 in 2084. By far, Korea is facing the most rapid population ageing among OECD countries. The old-age ratio would increase from (7.3 in 1964) 29.3 in 2024 to 122.0 in 2084 and Korea would move from being the tenth youngest country in the OECD in 2024 to the oldest in 2084, actually reaching this status by 2049.

The projected working-age population (20‑64) will remain virtually the same on average across the Asian economies, increasing by only 0.4% by 2064. However, it will fall by at least 29% in China (40%), Hong Kong (China) (63%), Singapore (29%) and Thailand (32%) (Figure 3.5). This will have a significant impact on the financing of pay-as-you-go (PAYGO) systems as it is closely related to their internal rates of return. Even funded pension systems might be negatively affected by rapidly declining working-age populations through its effect on labour supply, in turn potentially lowering output growth and equilibrium interest rates.

By contrast it is projected to increase by 11% in Indonesia, 14% in India, 18% in Malaysia, 24% in the Philippines and by 104% in Pakistan.

For the OECD the projected working-age population will decrease by 12% on average by 2064, i.e. by 0.31% per year. It will fall by 35% or more in Italy and Korea, and by more than 30% in Japan. It is projected to increase by more than 20% in Australia and by 9% in Canada.

The old-age to working-age demographic ratio is defined as the number of individuals aged 65 and over per 100 people of working age defined as those at ages 20 to 64.