Recently, 40 billionaires joined The Giving Pledge, launched by Microsoft founder Bill Gates, his wife Melinda and investor Warren Buffett, to donate at least half their wealth to charity.

Both Gates and Buffett are hoping their campaign will see commitments of at least $600 billion by the wealthy both within and outside the United States.

In Hong Kong, tycoon Li Ka-shing pledged last Thursday to donate more than HK$10 billion over the next 30 years.