The Giving Pledge effort led by billionaires Warren Buffett and Bill Gates added 17 individuals and families to the cause this week, bringing to 154 the number of signatories vowing to donate the majority of their wealth to charity.
Added pledgers include investor HRH Prince Alwaleed bin Talal, the wealthiest of the new group with a $19.8 billion fortune, according to the Bloomberg Billionaires Index, and the first from Saudi Arabia.