When 40 of the U.S.’s richest residents pledged to give away half their net worth in 2010, news outlets heralded the business giants who were “giving back in a big way.” Now, with more than 200 wealthy individuals and couples signed onto the Giving Pledge, a new report finds it might not be as big as expected.

According to a recent report from the Institute for Policy Studies, the 73 living signatories who were billionaires when the pledge launched in 2010 saw their wealth more than double by the end of 2022. Thirty of them—including prominent philanthropist couples Mark Zuckerberg and Priscilla Chan and Dustin Moskovitz and Cari Tuna—saw their wealth more than triple.

On top of that, much of that money was donated to private foundations, where it can sit indefinitely without being used to benefit anyone.

“Our worry is that most of the wealth that’s been pledged—trillions of dollars in wealth—will essentially wind up in private family foundations at the end of the day,” said Chuck Collins, director of the Charity Reform Initiative at the IPS and one of the report authors.

“The grandchildren of these billionaires will still be dribbling out the money,” he added. “And is that really the best use of our tax subsidy, if you will, for billionaire giving?”

The Giving Pledge was inspired by Chuck Feeney, an American businessman who donated almost all of his $8 billion fortune before he died in October. The signatories grew from a group of 40 of the richest Americans to an international alliance of 240 people and couples, including Bill Gates, Warren Buffett, Sheryl Sandberg, Marc Benioff, and—until his federal indictment—FTX co-founder Sam Bankman-Fried. The point of the pledge, according to its website, is to “inspire people to give more, establish their giving plans sooner, and give in smarter ways.”

The IPS report acknowledges some billionaires who are doing relatively well on that front: CNN founder Ted Turner, who has a net worth of $2.4 billion and has given at least $1.3 billion directly to charity, and Mackenzie Scott, who has donated $14.5 billion since her divorce from Jeff Bezos in 2019. “Mackenzie Scott has kind of been the great disruptor,” Collins said. “She’s showing the boys how to do it: You don’t need to create a huge apparatus, you just empty the vault.”

But even the pace of Scott’s giving is no match for the rapid wealth accumulation enjoyed by global billionaires. A report from Oxfam this year found that 63 percent of new wealth created since 2020 went to the 1 percent, and Giving Pledge signatories were no exception. Zuckerberg and Chang and Moskowitz and Tuna saw the largest wealth increases since 2010, with a more than 1,000 percent increase in their net worth since 2010. And 11 of the signatories saw their wealth increase by more than 500 percent, according to the report.

“Over the last 40 years, the rules of the economy have been changed to benefit asset ownership investors at the expense of wage earners,” Collins said. “Wealth is creating wealth at a pretty accelerating clip.”

The report also identifies the worst performers of the signatories, including a few who have received kudos in the past.

The authors single out Zuckerberg and Chan, who conduct the majority of their giving through the Chan Zuckerberg Initiative. Because it’s a limited liability corporation, not a nonprofit, the couple can use the money for political causes and lobbying efforts, and are subject to fewer disclosure requirements than if they gave through a traditional foundation. The initiative gave out $4.9 billion in grants as of 2020, but that pales in comparison to the $80 billion it reportedly has under management.

A spokesperson for the Chan Zuckerberg Initiative told The Daily Beast that, while limited liability companies are not required to do so, it voluntarily discloses its giving through a public grants database—something Forbes recently called “an uncommon show of transparency.” It also discloses the recipients of any gifts made through donor-advised funds. The spokesperson added that Zuckerberg and Chan have pledged to give away 99 percent of their Meta shares over the course of their lifetimes.

The report also zooms in on Elon Musk, the richest man in the world, who signed the pledge in 2012 but is accused of doling out self-serving donations. In 2021, for example, Musk sold $16 billion dollars worth of Tesla stock and donated $5.7 billion in Tesla shares to his foundation—a maneuver that saved him some $4.6 billion through tax write-offs, about the maximum percentage individuals can deduct. (The Oxfam report found Musk paid a “true tax rate” of about 3 percent between 2014 and 2018.) The Musk Foundation also donates frequently to people and causes close to the controversial billionaire: a school attended by his kids, a charity managed by his brother, and a nonprofit fighting traffic on the highway he drives to work, according to the report.

Other billionaires are simply not giving much at all. Spanx founder Sara Blakely, whose net worth is $1.1 billion, signed the pledge in 2013 and promoted it prominently on her foundation’s website but until two years ago had given less than $150,000 to that same foundation. Tax records filed after the IPS report was published show Blakely made a $9.9 million gift to the foundation in 2021. It is unclear what spurred that surge in giving, and a representative did not respond to a request for comment.

The authors repeatedly draw attention to the overwhelming use of intermediaries for charitable giving. According to the report, nearly all the signatories’ largest gifts have gone through their personal foundations or donor-advised funds—charitable investment accounts with much lower transparency requirements than foundations. A report from The Chronicle of Philanthropy found that 68 percent of all donations over $1 million in 2022 went through personal foundations or funds.

And while that might sound fine on the surface, the report notes that private foundations and donor-advised funds allow billionaires to donate large amounts—and reap large tax benefits—without actually giving away much. The minimum required donation for a charitable foundation each year is 5 percent of its assets, which can include overhead like staff salaries and office space. DAFs have no minimum payout requirement at all, meaning the money can sit for decades without being spent.

Some foundations even pay salaries to close friends and family members who serve as board members. The Conrad N. Hilton Foundation, endowed by the founder of the Hilton hotel chain, had $8.7 billion on hand in 2021 but gave away just $320 million in grants. It was able to count $30 million in overhead costs toward its minimum donation, including more than $3 million to the two co-chief investment officers and $35,000 each to the six Hilton family members on the board.

Collins says he refers to this process as the “warehousing” of charitable dollars.

“The money is getting waylaid,” he said. “It’s not in the river going to the nonprofit groups, it’s going to a side reservoir and pooling up, and becoming bigger and bigger.”

A spokesperson for the Hilton Foundation said the organization had doubled its staff in the last four years due to an increase in assets under management, which “resulted in an increase in operations costs,” and that it increased grantmaking in accordance with IRS guidelines.

“The Hilton Foundation takes a rigorous and thoughtful approach to ensure staff at all levels and in all functions are compensated fairly and appropriately through extensive audits of salaries for comparable roles and responsibilities across multiple sectors,” the spokesperson said, adding that the foundation’s articles of incorporation require that the majority of the board of directors be members of the Hilton Family.

Collins believes that the problem is not with the Giving Pledge signatories, but with a system that allows them to create these charitable wealth pools in the first place—and to reap benefits from them through tax breaks.

“We should have a system where the money flows in a more timely way,” he said. “The ultra-rich shouldn't be able to opt out of the tax system, because charity is not a substitute for a fair tax system and government investments.”