Nearly two months after her divorce from Amazon CEO Jeff Bezos was finalized, MacKenzie Bezos has made a plan to be far more generous than she and her former husband were as a couple. When the pair split, she became one of the richest women in the world, with a fortune estimated to be worth more than $36 billion. Now she wants to start giving it away.

“I have a disproportionate amount of money to share,” MacKenzie, a novelist, wrote bluntly in an otherwise literary letter announcing her decision to join the Giving Pledge Tuesday. “My approach to philanthropy will continue to be thoughtful. It will take time and effort and care. But I won’t wait. And I will keep at it until the safe is empty.”

Since it was founded by notable rich people Bill Gates, Melinda Gates, and Warren Buffet in 2010, the Giving Pledge has attracted over 200 wealthy individuals from around the world who publicly commit to donate at least half of their money either during their lifetimes or in their wills. While signaling you’re about to disperse at least $18 billion is notable under any circumstances, MacKenzie’s announcement attracted particular attention in part because the Bezos fortune has been tightly held so far. Jeff, literally the richest person in the world, has committed far less to philanthropic efforts. Last year, he announced he would spend just $2 billion of his $150 billion fortune on charity.

Louise Matsakis covers Amazon, internet law, and online culture for WIRED.

But even Jeff was willing to congratulate MacKenzie on her decision Tuesday. “MacKenzie is going to be amazing and thoughtful and effective at philanthropy, and I’m proud of her,” he wrote on Twitter. “Pay taxes, Jeff,” someone else replied. (Amazon paid no federal income taxes in 2018, in part as a result of Republican tax cuts passed the year before.)

That exchange neatly sums up the debate over the role of philanthropy in the US today.

In 1889, steel magnate Andrew Carnegie, perhaps the richest man in history, wrote a pamphlet called “The Gospel of Wealth,” in which he advocated for the wealthy to spend their lives donating to public institutions like libraries and universities. Carnegie called the practice “the true antidote for the temporary unequal distribution of wealth, the reconciliation of the rich and the poor—a reign of harmony.” The only problem is it hasn’t worked. Inequality in the United States is likely worse than it was during Carnegie’s era, despite the fact that the number of registered nonprofits in the United States has ballooned.

Meanwhile, the technology sector has made a small group of founders, early employees, and investors incredibly wealthy. Some of them have begun rebranding as philanthropists, like WhatsApp cofounder Brian Acton, Pinterest cofounder Paul Sciarra, and Brian Armstrong, CEO of cryptocurrency exchange Coinbase, who all signed the Giving Pledge in the past year as well.

But critics of the Giving Pledge and similar initiatives say they amount to little more than PR plays. If MacKenzie and her fellow elites spend their fortunes slower than they anticipate, there won't be any repercussions: They aren’t under any legal obligation to meet the requirements of the Giving Pledge, which its website describes as a “moral agreement.” It’s difficult to track whether every billionaire who signs adheres to the pledge, and several may not have done so, according to a Bloomberg report from 2015.

More broadly, charitable efforts carried out by the 1 percent don’t fix the systemic issues of inequality they have benefited from. “The richest and most powerful people in the world are unwittingly fighting on both sides of a war,” Anand Giridharadas, author of Winners Take All and a prominent critic of charity efforts in the tech sector, said at a WIRED conference last year. “Causing, by daylight, problems that they simply will never be able to undo by philanthropic moonlight.”