Vox recommended IPA it's roundup "These are the charities where your money will do the most good" because IPA is a meta-charity, a charity that improves how other charities work: 

"If they can turn a dollar of donations into substantially more than a dollar of increased donations to effective charities, isn't that the best use of my money?" asks Jeff Kaufman, a software developer who with his wife, Julia Wise, gives about half his income to effective charities and meta-charities.

We don't know nearly everything we need to know about reducing poverty in the developing world. We also need to know more about how to do effective advocacy, about what interventions are effective at reducing existential risk, and so forth. That's a good argument for Zuckerberg and Chan to fund more research into how to make charity more effective.