The most exclusive subset of the world's wealthy may be those living philanthropists who have already given away $1 billion or more, as listed by Forbes.
Of the world’s 793 billionaires, only 11 made it into this group. Says banking billionaire Herbert Sandler, "It's a shame there aren't a lot more."
Leading the elite group by almost an order of magnitude is Bill Gates, who has cut checks worth $28 billion during his lifetime. His fight against disease and eradicating poverty in developing countries has influenced many others to accelerate their giving.
In second place is hedge fund manager George Soros, who has given out $7.2 billion. Third place goes to Intel founder Gordon Moore, who has given away a total of $6.8 billion and backs environmental causes, including saving rain forests in South America and supporting marine ecosystems.
Warren Buffett is the fourth most generous donor in the world, who announced in June 2006 that, rather than start his own foundation, he'd transfer $30 billion in stock over 20 years into the Gates foundation. Buffett, who has given $6.4 billion so far.
All but one of Forbes' billion-dollar givers are self-made, including New York's Mayor Michael Bloomberg and Hong Kong's richest person, Li Ka-shing, who dropped out of school at age 15.
Scholars of philanthropy have noticed some interesting patterns about these super-philanthropists. Inherited wealth more often stays horded. "People who make their own money, entrepreneurs, are the most generous," says Leslie Lenkowsky, a professor at Indiana University's Center on Philanthropy. "They understand they've been very fortunate, and their good fortune in society depended on the schools they attended and their communities."
The only silver spoon among the super generous is Swiss billionaire Stephen Schmidheiny, who donated his company to a trust that distributes its profits to social causes in Latin America.