Recently, Facebook founder Mark Zuckerberg and his wife, pediatrician Priscilla Chan, made a big splash in the global health world when they announced a $3 billion commitment to “cure all diseases in our children’s lifetime.” Zuckerberg and Chan joined the ranks of wealthy philanthropists like Bill Gates who have decided to use their wealth to address global health.

Philanthropic organizations are playing an increasingly prominent role in global health, but their rise raises questions of accountability and whether deep-pocketed private organizations could distort the larger global health agenda. Here’s what you need to know about Chan’s and Zuckerberg’s plans.

What is the Chan Zuckerberg Initiative?

In December 2015, Chan and Zuckerberg created the Chan Zuckerberg Initiative (CZI) and pledged to sell up to $1 billion in Facebook shares for each of the next three years. Ultimately, the couple announced, they plan to give away 99 percent of their Facebook shares during their lifetimes to advance CZI’s goals of “advancing human potential and promoting equality.”

CZI will provide $3 billion over the next 10 years through a program called Chan Zuckerberg Science. Its first phase will provide $600 million to researchers at three San Francisco Bay-area universities — Stanford and the University of California at both Berkeley and San Francisco — to create the Chan Zuckerberg Biohub to focus on research and development of new techniques to treat diseases.

How is the approach of the Chan Zuckerberg Initiative different?

The approach differs from the usual approach of focusing on eradicating a specific disease, as is happening with Rotary International and polio eradication or the Carter Center and Guinea worm. CZI, rather, is concentrating on basic science, hoping that its discoveries will pay off down the line. Its strategy is akin to the Gates Foundation’s investments in research that could better global health, rather than funding clinical care or providing health services itself.

How much money is $3 billion in context?

While objectively $3 billion is a large amount, CZI’s pledge does not radically alter the balance of global health investments. The Institute for Health Metrics and Evaluation finds that donors pledged $36.4 billion for global health in 2015. If we assume that this funding remains flat and CZI allocates its funding in equal portions of $300 million each year, CZI’s pledge is less than 1 percent of total funding. Economist Charles Kenny points out that the world spends $7 trillion each year on health — totaling “more than 23,000 times the size of the annual Chan-Zuckerberg investment.”

What is the main criticism of CZI and similar endeavors?

Some observers have asked whether private organizations should launch independent public health efforts without oversight or any obligation to account for their work. Rather than putting its resources into an existing organization like the World Health Organization, CZI — like Gates — is creating its own institution and building its own network of collaborating institutions.

Moreover, Chan and Zuckerberg aren’t setting up a tax-exempt nonprofit organization akin to that of most philanthropies. CZI is a limited liability corporation. That means Chan and Zuckerberg receive no tax benefit, but they retain much more control over how CZI uses its resources and are subject to fewer public reporting requirements.

These decisions have provoked some backlash. Anil Dash criticized CZI for not channeling its resources through existing organizations and because of the likelihood of waste, while the Guardian questioned whether this sort of philanthropy can actually achieve social change. Sam Biddle alleges that CZI’s stated goals are too intangible and rooted in “a technocrat’s dream and an actual normal human being’s nightmare.” Gillian B. White argues that CZI’s corporate structure will allow it “to essentially do what it wants without traditional oversight.”

Do we want private individuals and institutions to have so much say in how the world tackles something as critical as health? Given CZI’s LLC status, it’s unclear whether outsiders will be able to assess the efficacy of its investments. Nor can the global health community know whether CZI’s attention can or will be sustained.

This is exactly the sort of criticism that the Gates Foundation has received for its oversized influence within the global health realm — that it is unaccountable, promotes a neoliberal and corporatist agenda that favors its founders’ ideology, and skews international aid priorities. Critics charge that the opacity of CZI and other private philanthropic funders allows them to set the global health agenda on their own terms — and potentially in opposition to what developing countries actually want in the health space.

But can CZI benefit global health anyway?

CZI and other global health philanthropies can complement other global health efforts. CZI can do things that organizations like WHO can’t do.

For example, organizations like WHO can’t really fund scientific research on their own. Organizations like CZI  have shown a greater willingness to take more risks than governments, shift resources around more quickly, and encourage national governments to continue to invest in global health. If CZI remains separate from WHO, Chan and Zuckerberg won’t be able to use their resources to change WHO’s agenda, a charge levied against many of the voluntary contributions given to WHO.

Instead, CZI is focusing its resources on one particular niche within global health, aiming to fill a gap rather than trying to be everything and encouraging bold strategies. What remains to be seen, of course, is whether its ambitious plan will yield useful outcomes.

CZI’s 10-year program isn’t likely to eliminate disease. Zuckerberg himself noted during Chan Zuckerberg Science’s unveiling that it “doesn’t mean no one will ever get sick.” But CZI’s efforts can add to what the world already has, bringing more research and more attention to global health.

Jeremy Youde is a fellow and senior lecturer in international relations at the Australian National University and chairperson of the Global Health section of the International Studies Association. Follow him on Twitter @jeremyyoude.