An aging population and the increasing demand for highly-skilled workers has further widened the income gap in Hong Kong in 2011, raising concern over the country's economic health, a report by Bloomberg shows.

Citing figures from the Census and Statistics Department of Hong Kong, the news service said that the city's Gini coefficient, or the measure of income equality, rose to 0.537 last year, from 0.525 in 2001. While the increase may seem small, it is important to note that the recorded gap is wider than in Singapore, Canada, Australia, the UK and the US.

The Gini coefficient index is recorded as a zero to one range, with a zero reading indicating income inequality and one indicating complete inequality. Singapore's coefficient reportedly went up to 0.482 in 2011, from 0.456 recorded in 2001.

Economic restructuring had shifted the demand for labor from traditional low-skilled workers to high-skilled, high-income individuals, thus widening the gap even more. This condition is also affected by the rising number of retirees. To-date, around a fifth of seven million residents in the city earn less than half the median pay, the news service said. Between 2001 and 2011, the average gross household income of Hong Kong's poorest 10 per cent dropped from HK$2,590 in 2001 to HK$2,170 ($280) in 2011. This contrasts greatly with the income of 10 per cent richest, which grew from HK$122,740 to HK$137,480.

It remains unknown how the goverment will resolve the problem. Donald Tsang, the outgoing chief executive of Hong Kong, has offered tax, rent and utilities rebates to citizens to counter the gap. Incoming chief Leung Chun-ying has also promised to help low-income earners and increase housing supply when he officially takes office in 1 July.