Key Takeaways
A new Stanford Social Innovation Review essay from Bridgespan cofounder Jeffrey Bradach names the pattern "slow philanthropy," with families above $500 million giving away about 1.2 percent of assets a year.
The 1.2 percent rate was essentially unchanged from 2017 to 2023 while those fortunes compounded at roughly 9 percent, so most large fortunes grow faster than they are given away.
MacKenzie Scott is the counterexample with more than $26 billion given since 2019, and charitable bequests hit a record $62 billion in 2025.
Bridgespan Group cofounder Jeffrey Bradach published an essay in the Stanford Social Innovation Review on July 30 that gives a name to big philanthropy's defining problem. He calls it slow philanthropy, and the numbers behind it are blunt.
Bridgespan found that US families holding more than $500 million in assets gave away about 1.2 percent of those assets in 2017. When researchers reran the numbers for 2023, the rate was essentially unchanged, even though those fortunes had been compounding at roughly 9 percent a year, Fortune reported. The wealth grows faster than the giving, so the pile gets bigger every year the money stays parked.
The Institute for Policy Studies found the same drift in the Giving Pledge. Three quarters of the original US signers who are still alive remain billionaires today, and just 8 of 22 deceased pledgers fulfilled their commitments.
Bradach points to one large exception. MacKenzie Scott has given away more than $26 billion since 2019 in unrestricted, trust based grants, a pace that makes her "the most generous individual philanthropist of this century" in his words. "I will keep at it until the safe is empty," Scott wrote in her 2019 Giving Pledge letter.
One channel is already moving faster. Charitable bequests hit a record $62 billion in 2025, outpacing growth in giving by living donors, because a bequest separates the decision to commit from the decision of where the money goes.
The gap between pledged money and moved money is the number to watch across the whole sector. It showed up when Warren Buffett redirected $6 billion of his giving, and it is why community results like Give 716's record $1.8 million day matter, small donors move money the same week they commit it.
People Also Ask
What is slow philanthropy?
It is Bridgespan cofounder Jeffrey Bradach's term for ultra wealthy giving that lags far behind stated ambitions, with assets growing faster than donations flow out.
How much do billionaires actually give each year?
Bridgespan found families with more than $500 million in assets gave away about 1.2 percent of those assets per year in both 2017 and 2023.
How much has MacKenzie Scott donated?
More than $26 billion since 2019, given mostly as unrestricted gifts that nonprofits can spend however they judge best.
Did Giving Pledge signers keep their promises?
Mostly not yet. The Institute for Policy Studies reports just 8 of 22 deceased US pledgers fulfilled their pledges, and three quarters of living original signers remain billionaires.