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Like everything else in the world, it seems, celebrity fundraising has gone virtual too. Over the last few weeks, Sting & Shaggy performed over a video call for Stream Aid 2020. Sarah Silverman and Ben Affleck faced off on a Twitch-streamed poker game to raise money for Feeding America. And Mindy Kaling read Red Riding Hood for Save the Children and No Kid Hungry.

Jacinta David-Miller, a Planet Money listener, wrote in wondering how effective these charities might be. She says she is "unsure as to what impact these donations have." It's a question we wanted to learn more about too.

We called up James Snowden, a senior research analyst at . GiveWell is based in Oakland. They're like a Michelin guide for do-gooders, and they're backed up by numbers. They have a neat slogan: "We search for the charities that save or improve lives the most per dollar." They're optimizers.

Snowden told us that, before the coronavirus pandemic, GiveWell's top recommended charity was . Malaria kills about 450,000 people a year, so Malaria Consortium goes door to door in places like Burkina Faso to give out antimalarial pills to children. Snowden says you can save a life through this charity for between $2,000 and $3,000. "It's really remarkable how much impact you can have by being willing to give outside your own country," he says.

We wanted to know whether the coronavirus pandemic had changed everything. Snowden says he's looked through the available evidence. Because COVID-19 is such a new disease, there aren't many rigorous studies, like randomized controlled trials, which GiveWell normally relies on. And, Snowden says, that $2,000-per-life figure is just "a really high bar to clear." So Snowden says they're still recommending people donate to the same top charities they did before the coronavirus. Malaria remains a huge killer.

That said, he found three efforts to combat the coronavirus that looked so promising that he and his team granted them a total of $450,000. One of these was , a charity that sends out public health messages in low-income countries. They're broadcasting radio ads in nine African countries for basic coronavirus prevention measures like good hand washing, coughing etiquette, and physical distancing. The charity's past efforts with pneumonia messaging — confirmed with a randomized controlled trial — gave Snowden confidence that these radio advertisements will be effective.

Snowden says that GiveWell didn't have a recommended charity for the US. "If we truly believe that every life across the world is of equal value, then we just see much better opportunities to prevent more deaths in low-income countries than we do in high-income countries."

For those who really just want to donate within the US, Snowden mentioned , which hands out cash with no strings attached. GiveDirectly usually direct this cash only to people in low-income countries, but in April it established a new program where you can donate directly to low-income Americans affected by the coronavirus crisis. "Given that we have a very strong opinion of GiveDirectly as an organization," Snowden says, "I think we could reasonably say that it would be a good way to help those in your own community."

We're about five months into the spread of the novel coronavirus. As the number of cases grows, so does the evidence about how to most cost-effectively save lives. Snowden says GiveWell will continue to assess COVID-19-related giving as the studies come in.

Not everyone agrees with the mechanical life-per-dollar approach of GiveWell. And Snowden himself acknowledges that continually assessing costs and benefits can be exhausting. "When I finish the day I just want to have a pizza and relax," he says.

Though, who knows, this could be Snowden's optimization brain still at work. Pizza probably ranks high in maximizing calories-per-dollar, if that's what you're after.

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