Bill and Melinda Gates used their Gates Foundation annual letter to address tough questions they regularly hear about their work. (Daniel Berman/For The Washington Post)

Bill and Melinda Gates, by many measures, are popular public figures.

According to a poll taken during the 2016 election, 58 percent of registered voters see the Bill & Melinda Gates Foundation favorably, more than the 45 percent who feel the same about the Rockefeller Foundation or the 33 percent who have a positive view of the Clinton Foundation. The Gateses have received honors and awards for their work giving away the foundation’s billions. The Microsoft founder would even do well if he ran for president, according to research by Fidelum Partners, which also found that Bill Gates ranked higher than many celebrities on a matrix the research firm called a “human brand perception map.” (Ellen DeGeneres had a higher “warmth” score).

So why did the billionaire philanthropists use their foundation’s annual letter this year to answer questions some critics have raised? Why have the “first couple of American philanthropy” — as one industry watcher called them — opened up on 10 “tough questions” about whether it’s fair they have so much influence, why they don’t spend more of their billions in the United States, and what they have to show for their efforts to reform U.S. public schools?

The answer, according to the pair, who sat for a recent interview with The Washington Post, is that the foundation’s 10th annual letter was a good year to take on the questions they get most often. “We really decided it would be good to group them up so that people can see how we think about these questions,” Melinda Gates said in the interview, noting that “you build trust over time” if “you’re knowable, if you’re transparent.”

Bill Gates said, “We’re very open in terms of what we’re doing,” saying Warren Buffett inspired him with his forthright letters when he started writing them 10 years ago.

Yet some experts on philanthropy said they believed the “tough questions” format of the letter was a sign the Gateses are aware there are storm clouds of public opinion gathering on the horizon. It suggests they are attuned to the times: Public distrust of global institutions is rising. Surging income inequality is triggering alarms. And there is a growing unease about the role that the ultrawealthy play in society.

“If you run the Gates Foundation, you have to be thinking about making sure it doesn’t become one of those institutions that Americans distrust,” said David Callahan, author of “The Givers: Wealth, Power and Philanthropy in a New Gilded Age” and editor of Inside Philanthropy. “They have to be thinking about it, and judging by their letter, they clearly are.”

Even if the letter was not intended as a direct response, Americans’ overall trust in institutions plummeted to record lows this year, driven by a plunge in their view of government. According to Edelman’s 2018 Trust Barometer, released in January, members of the “informed public” in the United States viewed nongovernmental organizations, the type of organization in the survey closest to the Gates Foundation’s work, 22 percentage points lower than they did in 2017.

Gates Foundation co-chairs Bill and Melinda Gates talk about their efforts to cure AIDS, what it’s like dealing with the Trump administration and the toughest questions they ask each other. (Whitney Shefte/The Washington Post)

A more subtle shift has been taking place for some time, said Benjamin Soskis, a research associate at the Center on Nonprofits and Philanthropy at the Urban Institute.

“To be a mega philanthropist means having to confront the dangers of unequal power in a way you might not have had to do two decades ago,” said Soskis, who said a portion of his research is funded by the Gates Foundation.

He points to the shift in conversation about philanthropy since 2006, when Buffett’s pledge to donate more than $30 billion of his fortune to the Gates Foundation was greeted with much celebration.

Now, “the general discourse around philanthropy — the default attitude — has shifted slightly away from a natural pose of gratitude toward one of some degree of critical scrutiny,” he said. “That’s shaping the way the media covers philanthropy and the way the general educated populace is starting to regard the prerogatives of big donors. It’s linked quite naturally to concerns about inequalities of wealth.”

It’s that general educated audience, as well as other major donors — not populists with pitchforks or philanthropic critics on the left — to whom Soskis thinks the Gates letter is addressed. In it, the Gateses discuss why they’re giving their money away (and say that it isn’t about their legacy but rather that it’s “meaningful work” and “we have fun doing it”); acknowledge “it’s not fair that our wealth opens doors that are closed to most people”; answer the critique of whether they’re imposing their values on other cultures; and say there is “nothing secret” about their foundation’s goals.

They also address topics that critics have raised over the years. While the Gateses have been widely praised for their philanthropic efforts to eradicate polio, reduce childhood deaths in the developing world and combat HIV and malaria, they have also come in for plenty of criticism.

A lab worker is seen at the Life Science and Translational Research Center in Rockville, Md. A malaria vaccine manufacturing facility at the research center is supported by a $29.3 million grant from the Bill & Melinda Gates Foundation. (Brendan Smialowski/Getty Images)

Some in the global health world and academia have asked whether by virtue of its vast size — the foundation’s trust endowment tops $40 billion — it has too much dominance over research or aid priorities. Meanwhile, education advocates have criticized the Gateses’ support for the Common Core State Standards as well as what they say is a top-down approach to school reform, questioning the results of initiatives that have seen billions poured into them. As the Los Angeles Times editorial board put it in 2016: “Philanthropists are not generally education experts, and even if they hire scholars and experts, public officials shouldn’t be allowing them to set the policy agenda for the nation’s public schools.”

And a more complex, systemic debate surrounds the issue of accountability of large foundations. Global corporations must answer to their shareholders, and elected leaders must answer to voters, but large foundations don’t have the same oversight. While that gives them the freedom to experiment and fail in ways that governments and businesses may not, it also prompts observers to question whom they answer to.

“Having a bunch of unaccountable power in the hands of philanthropists,” Callahan said, “is at odds with the idea of democracy.”

He says the Gates Foundation is more transparent than many foundations, a signal the letter sends. “The subtext is, ‘We hear you,’ ” he said. “They do a great job of explaining what they’re up to and publicize their grants in real time.”

But with only three trustees (the Gateses and Buffett; Bill’s father is a co-chair), Callahan believes it could have a more diverse board. The foundation does have a scientific advisory committee consisting of outside experts, and its U.S. program also has an advisory panel.

Susan Desmond-Hellmann, the chief executive of the Gates Foundation, said in an interview that the letter was evidence of the Gateses’ comfort level with difficult discussions. She did, meanwhile, agree that there is growing demand by the public for institutions to be transparent and accountable. “Inequity is more visible, and more part of the public discourse, now than ever before,” she said, noting that a societal motto for 2017 could have been “the end of secrets.”

Bill and Melinda Gates walk on a street in Dhaka, Bangladesh, where the Bill and Melinda Gates Foundation funds health programs, in 2005. (Gazi Sarwar/Associated Press)

Bill and Melinda Gates “have great families, great values and want to give back,” Desmond-Hellmann said. “They are role modeling what an answer to the inequity discussion could be, which is to donate your wealth to helping the world be more equitable.”

In addition to posting grants online, the Gates Foundation requires its grantees to make their research publicly available, posts financial data on its website and has committed to report on its progress against the U.N. Sustainable Development Goals.

One challenge for the Gateses’ letter is that while it’s important for leaders to open up to answering tough questions, it can potentially also leave them open to criticism, such as why some issues were addressed and not others.

“If you set yourself as the good guy, the good news is people respect that,” said Paul Argenti, a professor at Dartmouth’s Tuck School of Business who studies communications strategy. “But you have to be willing to take the incredible heat that’s going to come along with that, too.”

In the interview, Bill Gates said he’d “be surprised” if the questions that came up after the letter were tougher than the ones they selected, saying that “we didn’t dodge. We didn’t optimize for easiness.” He also said they plan to answer more questions that come up in the comments of their online letter. (More than 1,300 have already been submitted online, from “Do you see an irreversible trend in private foundations taking on a good chunk of the work that is usually associated with governments?” to “Help me buy a one-room apartment in Moscow.”)

Gates also said in the letter that “we know that some of our critics don’t speak up because they don’t want to risk losing money.” In the interview, he said the foundation’s experts engage “quite a bit” with academics but recognize they have to encourage discussion within the field. “We have to say that we desire that,” he said.

The foundation surveys partners every two years and works with outsiders as it develops strategies, Melinda Gates said in the interview. “We actually put it out to many, many experts — practitioners, academics — before it’s finalized, long before it’s finalized,” she said. “What we hear in the first round will actually hone our thinking, or the team’s thinking, and we may adjust what we’re thinking of doing and put it out again.”

Some observers of the foundation appreciated the letter’s tone or were struck by what was included. Megan Tompkins-Stange, an assistant professor at the University of Michigan and the author of a book on the influence of philanthropists on education, said “to even see the Gates Foundation talking about that view” regarding the scope of its influence “was really notable. I haven’t seen that before. The language was very open.”

American Federation of Teachers President Randi Weingarten, who has worked with the Gates Foundation but also stopped taking grants from it in 2014 for the group’s Innovation Fund — “I got convinced by the level of distrust I was seeing,” she told Politico at the time — said the Gateses’ letter, combined with a speech last year where Bill Gates announced a pivot in the foundation’s strategy toward funding more locally driven ideas, “feels like a real shift.”

Craig Ferguson, who works for Denver Public Schools, sets up a video recording system that collects data for a research project from the Bill and Melinda Gates Foundation. (Andy Cross/Denver Post/Getty Images)

She liked the line about building “consensus among a wide range of decision-makers,” including teachers and parents, and said if they actually follow through, it could help win over skeptics. “I think, frankly, this is worth giving the Gates Foundation credit for,” she said.

But other critics saw gaps in the letter or were less enthused. Tom Loveless, a former senior fellow at the Brookings Institution and a Gates Foundation critic, said that the question selected about education “doesn’t have the specificity of: ‘Do you think it was a mistake to fund Common Core?’ ” and that he didn’t think it included much substance on a strategy shift.

The letter also could have been more reflective about how the foundation is changing internally, he said. “If they’ve stumbled and stubbed their toe, I would have liked to hear them say, ‘We’re hiring an in-house ombudsmen or an in-house skeptic.’ ” And while he said there was a touch of humility, he thought the letter felt more like “seasoning than the meal.”

Sophie Harman, a professor of international politics at Queen Mary University of London who has questioned why the Gates Foundation doesn’t get more scrutiny, said Bill and Melinda Gates took on big questions about the Trump administration, climate change and population control in the letter and was encouraged to see them acknowledge their level of influence, saying it’s a good “first step.”

But she also felt the questions glossed over some details and would have liked to see them directly address reforming of the World Health Organization and criticism that they focus too much on technological solutions to health care.

“If you sat down with the ministry of health” in some of these developing countries, she said, what you’d hear is “the need for more doctors, more hospitals, more clinicians, more laboratories — all the things you’d expect from contemporary health systems.” While “it’s good they’re acknowledging their influence, now I want to see what they do with that acknowledgment.”

Bill Gates speaks with villagers in Aulali, India, in May 2010 during a visit to see the progress the government was making in its campaign to eradicate polio. (Prashant Ravi/AP)

Melinda Gates visits a hospital in Dangbo, Benin, with French first lady Carla Bruni-Sarkozy and Michel Kazatchkine, executive director of the Global Fund to Fight AIDS, in January 2010. (Eric Feferberg/Pool/AP)

Steve Davis, chief executive of PATH, an global health nonprofit and one of the Gates Foundation’s oldest partners, said Bill and Melinda Gates “are conscious” of the gravitational pull their funding and their access to world leaders can cause.

“We have an obligation — they have an obligation — to push back, to disagree, to be willing to not always align with what they’re thinking,” he said, calling it the reality and an “almost inevitable challenge.”

While the foundation’s size has many advantages, Melinda Gates acknowledges it can also make its work harder. “Everything we do now is under a microscope. It’s out in public,” she said. “If you’re a smaller foundation, you often get to work behind the scenes when you’re in a learning mode or before you do something big. We’re not in that mode anymore.”