If ageing were an Olympic discipline, Asian societies would be vying for the gold medal. With their declining fertility rates and rosy life expectancy statistics, countries such as Japan and South Korea are greying at an impressively fast rate. Yet while it is a sign of economic success, high-speed ageing has become a tricky public policy issue.

The crux of the problem lies in the so-called dependency ratio – the number of people of working age for every pensioner. In China, for example, this ratio is expected to drop from 6:1 to 2:1 over the next 30 years, leaving the government with unpalatable policy options: reducing benefits, increasing contributions and lifting the retirement age.