Sometimes donors expect that they can save a life for much less than $5,000, and they’re surprised to encounter our estimate. But most come to share my belief that $5,000 to save a life is a bargain. We aim to be fully transparent about what goes into our cost-effectiveness estimates—including the counterarguments, caveats, assumptions, best guesses, and moral judgments. This transparency gives them the confidence to give more.It’s true that in the US we focus so intently on quality of life that we may not appreciate that we have lives in the first place, that comparatively few of our children die as infants. But aren’t some of the people saved by, say, malaria nets, going to have really hard lives?This is a sad reality about things, that we don’t even think about how lucky we are. And if you reverse the question you asked, it can sound like you’re basically wondering if one might be very wealthy and have great physical health and still be unhappy. Clearly you can be.Why have so many EAs turned their attention from preventing disease to cooking up Book-of-Revelation scenarios involving AI?Many EAs continue to work on global health. But the rapid advancement in powerful AI systems should raise real concerns for everyone. Myself included.When I started getting interested in the philosophy of EA, there was some freaky stuff.You mean those scary questions, like, “Would you let your mom die to save 100 strangers?”Exactly. But I think there are enough challenges in the world that we need every person focused on the area where they think they can have the biggest impact. I’m glad there are a lot of great minds focused on AI and the broader questions in EA. Me, personally, I can bring something to helping people who are suffering right now.So you built the nonprofit GiveWell after working at Bridgewater, an investment fund that is [checks notes] for-profit, yes?Yes. And in the beginning there were a lot of stories about Holden and me, how “hedge fund veterans” were turning to philanthropy. But we were only 26, and we’d been at the fund for only a few years. Very soon Holden and I were talking with friends about how to give money away.I chose the cause of clean water in Africa. I don’t know how or why I chose it. I probably thought something like, Water is a basic human need. Giving money to provide access to clean water seemed like a good thing to do. In the early days of GiveWell, we noticed that diarrhea and dehydration are among the leading causes of death. Why? How? I just got totally obsessed with this: We live in a world where people without clean water die of diarrhea. But clean water has not been a good we can deliver yet. To be honest, I still wish we could do more to provide people with water that won’t cause disease.Why is that difficult?