MacKenzie Bezos, the world’s third-richest woman following her divorce from Amazon founder and CEO Jeff Bezos, has signed the Giving Pledge — a commitment that will see her giving away more than half her wealth to philanthropy or charitable causes, either during her lifetime or in her will.

Bezos recently made headlines when she gave ex-husband Jeff 75% of their joint Amazon stock, and voting control, in their divorce, along with their interests in The Washington Post and Blue Origin. However, that still left her with an at least $35.6 billion stake in Amazon. Bloomberg’s Billionaires Index now estimates her net worth at $36.6 billion.

“We each come by the gifts we have to offer by an infinite series of influences and lucky breaks we can never fully understand,” wrote MacKenzie Bezos, in a letter published by the Giving Pledge today, announcing her intention to give away her wealth.

“In addition to whatever assets life has nurtured in me, I have a disproportionate amount of money to share. 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,” she said.

Ex-husband Jeff Bezos tweeted praise for MacKenzie’s pledge this morning:

Jeff Bezos, now the world’s richest person ahead of both Bill Gates and Warren Buffett, has not signed the Giving Pledge himself.

Founded in 2010 by Bill and Melinda Gates and Warren Buffett, the Giving Pledge encourages the world’s richest people to give away more than half their wealth. Other notable names who have previously signed the pledge include Mark Zuckerberg and Priscilla Chan, Elon Musk, Richard Branson, Larry Ellison, Michael R. Bloomberg, Pierre Omidyar and many more.

Today, the program announced 19 more philanthropists have signed their names to the pledge, bringing the total number of signatories to 204.

In addition to Bezos, other tech industry additions announced today include: Tegan and Brian Acton — the latter who co-founded WhatsApp, the messaging app bought by Facebook in 2014 for $19 billion; Coinbase co-founder and CEO Brian Armstrong; co-founder of bitcoin trading platform BitMEX Ben Delo; Twilio CEO Jeff Lawson and Erica Lawson; Lowercase Capital partners Chris and Crystal Sacca; and Pinterest co-founder Paul Sciarra and Jennifer Sciarra.

Globally, there are now signatories from 23 countries: Australia, Brazil, Canada, China, Cyprus, Germany, India, Indonesia, Israel, Malaysia, Monaco, Norway, Russia, Saudi Arabia, Slovenia, South Africa, Switzerland, Tanzania, Turkey, Ukraine, United Arab Emirates, the United Kingdom and the United States. In the U.S., the largest contingents are from New York and California.

Bezos’ full letter detailing her plans is below:

May 25, 2019

Thinking about the Giving Pledge, my mind kept searching its folds for a passage I once read about writing, something about not saving our best ideas for later chapters, about using them now.

I found it this morning on a shelf of my books from college, toward the end of Annie Dillard’s The Writing Life. It was underlined and starred like all of the words that have inspired me most over the years, words that felt true in context, and also true in life:

“Do not hoard what seems good for a later place in the book, or for another book… The impulse to save something good for a better place later is the signal to spend it now. Something more will arise for later, something better… Anything you do not give freely and abundantly becomes lost to you. You open your safe and find ashes.”

I have no doubt that tremendous value comes when people act quickly on the impulse to give. No drive has more positive ripple effects than the desire to be of service. There are lots of resources each of us can pull from our safes to share with others — time, attention, knowledge, patience, creativity, talent, effort, humor, compassion. And sure enough, something greater rises up every time we give: the easy breathing of a friend we sit with when we had other plans, the relief on our child’s face when we share the story of our own mistake, laughter at the well-timed joke we tell to someone who is crying, the excitement of the kids in the school we send books to, the safety of the families who sleep in the shelters we fund. These immediate results are only the beginning. Their value keeps multiplying and spreading in ways we may never know.

We each come by the gifts we have to offer by an infinite series of influences and lucky breaks we can never fully understand. In addition to whatever assets life has nurtured in me, I have a disproportionate amount of money to share. 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.

MacKenzie Bezos