The Giving Pledge, launched by Warren Buffett and Bill Gates in 2010, has 81 billionaire signers so far, each of whom have pledged to give away at least half of their wealth.
“The average age in this group is trending higher, more toward seniors,” said Bradford Smith, president of the Foundation Center, which has launched "Eye on the Giving Pledge" to research and analyze pledge givers and their causes. “Banking and finance is the most common industry where they made their wealth.”
“Eye on the Giving Pledge" tracks the billionaires who have signed the pledge and looks at how they made, and give away, their fortunes.
Smith says that combined net worth of the signers is about $400 billion, so “the commitments made by the signers could bring an estimated $200 billion or more to charity over time.” To put that in context, all of the foundations in America have a current estimated $646 billion in assets and give $46.9 billion a year, Smith said.
By looking closer at the Giving Pledge money, Smith says, we can get a better understanding of how today’s biggest givers are approaching philanthropy and targeting change.
The sources of their wealth are also revealing. The top industry of the Giving Pledge signers is banking and finance: 29 percent of the givers made their money in banking or finance. Tech and software came in second, with 24 percent, followed by industrial manufacturing (13 percent) and retail (10 percent) and entertainment/media (9 percent).
The Pledge signers are mostly senior citizens: 56 percent are over the age of 65. Only two, Facebook founders Mark Zuckerberg and Dustin Moskovitz, are under the age of 35.
When it comes to favorite philanthropic causes, health ranked first, followed by education, human services, and arts and culture. Smith said these patterns mirror broader philanthropic giving in America.
“Health and education are really the largest areas,” he said.
Smith said another trend emerging from the analysis is that many of the top signers are making big, bold bets to solve social problems. Hedge funder Bill Ackman and his wife, Karen, gave $10 million to Human Rights Watch. Lorry Lokey, founder of Business Wire, donated $74.5 million to the University of Oregon for science programs. Denny Sanford, the banking entrepreneur, pledged $400 million for pediatric health and rural health-care.
“It’s important to realize that these people with very substantial wealth are not afraid to make these courageous bets,” he said.
-By CNBC's Robert Frank
Follow Robert Frank on Twitter: @robtfrank
CORRECTION: An earlier version of this story identifed Bill Ackman's wife as Susan. Her name is Karen.