Bill Gates and Warren Buffett have convinced 11 more billionaires to give away half of their wealth. The richies, including Netflix CEO Reed Hastings, will bring the total number of families participating in the "Giving Pledge" to 92. The campaign, launched two years ago, aims to convince the wealthy to donate big money to philanthropies, and to think carefully about targeting money now to projects they believe in. It's not yet clear, however, what kind of impact the strategy is having—though Gates believes donors "are collaborating" to increase the money's impact, reports the Wall Street Journal.
Others are less certain. "It is terrific as long as we see an increase in philanthropic projects," Salesforce.com founder Marc Benioff tells the Journal. But "it's been two years; what are the 10 or 20 major projects that come out of it?" Benioff has donated $100 million to a children's hospital, but hasn't signed the pledge. German shipping magnate Peter Kramer believes more of the wealth should be taxed so the public can decide how to spend the money. "A few rich men shouldn't decide on the allocation of many, many billions of dollars for the public's benefit," he says. Estimated charitable giving in the US increased 4% last year over the previous year to $298 billion. The Giving Pledge doesn't keep track of donations. (Read more Warren Buffett stories.)