After More Than $1 Billion in Funding, MacArthur’s Big Bets Are Winding Down. What Happens Now?

nuclear security is one of four big bet programs macarthur is currently wrapping up. maradon 333/shutterstock

When Julia Stasch took over at the MacArthur Foundation in 2014, she inherited a sprawling beast of a funder that had 18 programs on its website, plus various special projects and research networks. She needed to narrow its focus, and to do so, committed to a series of “Big Bets,” time-limited efforts to achieve transformative change in a set of fields. 

While the idea of philanthropy as a big bet was nothing new, Stasch’s model was a bold philosophical stake in the ground, channeling MacArthur’s massive resources not into perpetual priority areas, but into targeted efforts that could yield quantifiable outcomes within a window of time. MacArthur sharpened its focus to such an extent that by the time Stasch left the foundation in 2019, it was in the process of winding down 13 areas of work.

MacArthur’s Big Bets program was “an innovative approach to seeking a more impactful, accountable and learning-based approach to grantmaking,” said Dr. Amir Pasic, Eugene R. Tempel Dean of the Indiana University Lilly Family School of Philanthropy, who has been keeping a close eye on MacArthur’s work for a while. 

But any bet carries risk, and one key trait built into MacArthur’s Big Bets is that they come to an end. Ten years after Stasch took over and four years after she stepped down, all four of the Big Bets that launched during her regime are either done or winding down in the next few years — Nuclear Security (closed in 2023), On Nigeria (2024), Criminal Justice (2025) and Climate Solutions (2026). 

This leaves the foundation at a critical inflection point, with current President John Palfrey and his team working with grantees and community leaders to identify new strategies. As it continues to wind down its existing Big Bets, MacArthur is expected to announce several new program areas within the next three to five years. Other ongoing commitments, such as the MacArthur Fellowships and dedicated funding for Chicago will continue, but a lot could change at this storied institution.

One new initiative we do know about is Press Forward, a five-year effort to move more than $500 million to boost local news in collaboration with 21 other funders. But the foundation could not yet say whether the time-limited Big Bet strategy would be applied to future funding areas. It’s also unclear to what extent the foundation will continue funding within some of the Big Bet issue areas, or supporting past grantees from those initiatives. “Some grantees today will end up being grantees in programs in the future, and others will not,” Palfrey said in a recent interview with IP.

These kinds of strategic pivots are not uncommon in philanthropy, but they don’t occur in a vacuum. Any shift in priorities, even if telegraphed years in advance, could leave an organization or a field worse off — especially if there aren’t any other funders to fill the gap. Now that MacArthur is executing four such pivots over the span of just a few years, what does that mean for the global problems it’s been taking on, and the grantees working in these fields? 

I posed the question to several grantees and, not surprisingly, those I spoke with were uniformly grateful for MacArthur’s support throughout the years, and for how foundation staff guided them through the wind-down process and even helped them secure other funding. At the same time, some leaders said that the program closures would indeed prove problematic; we’re already getting a sense of what that looks like with the closure of the Nuclear Security program, which has received extensive support since the 1980s. That field is facing the most acute challenges following the grantmaker’s exit, according to grantees, given its small base of funders, the threat of nuclear conflict in Ukraine and other festering geopolitical instabilities. 

“MacArthur’s wind-down will prove and is proving disruptive,” said Rachel Bronson, the president and CEO of the Bulletin of the Atomic Scientists, a Chicago-based organization that focuses on existential man-made threats.

The unique position MacArthur now finds itself in raises tough questions around how large global grantmakers seek to renew their strategies without adversely affecting the ecosystems they had cultivated for years, not to mention the longstanding push and pull in the sector between providing bursts of funding in search of acute impact and steady streams of potentially unending support. That’s especially relevant in a world that is fast-changing and facing multiple existential threats.

“No foundation enjoys ending a program, and no grantee likes to be on the receiving end of the end of the program,” Palfrey said. “But it’s also necessary, because if we don’t end programs, we won’t be able to change with the times and have a more diverse set of grantees, which is something we’re seeking to do.”

A crucial stream of support 

When trying to understand the legacy of the Big Bets, it’s important to understand just how much money it’s moved out the door through the program — $130.2 million to 94 organizations through Nuclear Challenges; $139.5 million to 124 organizations through On Nigeria; $323.1 million to 127 organizations through Criminal Justice; and $458.7 million to 138 organizations through Climate Solutions. That’s $1.05 billion to 483 nonprofits, not counting the other non-Big Bet funding MacArthur has disbursed over the past decade.

Reflecting the sheer size of MacArthur’s presence in these fields, leaders from all four areas stressed that MacArthur funding has been critical to their organizations. In an email to IP, the Bulletin for Atomic Scientists’ Bronson said support has enabled it to connect “the work and recommendations of key scientists and experts to influential policymakers and has mentored new generations of leaders committed to this work.” Accountability Lab Nigeria Country Director Odeh Friday said via email that MacArthur funding “offered us credibility, expanded our network access, facilitated learning opportunities and fueled innovation through our programs.”

Leaders also lauded MacArthur’s user-friendly grantmaking mechanics. Chéri Smith, founder and CEO of the Narragansett, Rhode Island-based Alliance for Tribal Clean Energy, cited the foundation’s penchant for unrestricted funding and that “they’ve made it easy and equitable for a small, Indigenous-led organization like ours to apply for a seven-figure grant.” In a similar vein, John Tierney, executive director of the Center for Arms Control & Non-Proliferation, told me his organization “didn’t have to go through the application process every year as long as things were on track. That was very useful for planning purposes and time consumption.”

Also to MacArthur’s credit: Even as some grantees are unhappy with the outcome, the process surrounding the Big Bets wind-down was a careful one. Beginning in 2021, MacArthur reps were in conversation with Big Bet grantees about the wind-down of the strategy, and publicly announced it in September 2022. Palfrey, who succeeded Stasch in 2019, told me that MacArthur is “on schedule with the strategy of both investing quite heavily in a series of fields, hopefully communicating effectively about our timeline, and exiting gracefully — although, of course, it’s always painful.”

MacArthur is providing grantees with capacity-building training and tie-off grants. It’s also communicating with donor partners about funding gaps, which has already generated new support in fields like criminal justice and climate. Leaders expressed appreciation for that wind-down process.

Accountability Lab’s Friday acknowledged the “transparent and gracious communication from our MacArthur colleagues regarding the funding transition.” Similarly, Jennifer Vollen-Katz, executive director of Chicago-based criminal justice watchdog the John Howard Association, said the foundation “has been clear with JHA since 2022 that the program area under which JHA receives support is winding down and that our current grant will be our last.”

And as far as the Nuclear Challenges Big Bet is concerned, MacArthur “signaled that it would sunset its Big Bet and gave us three years to prepare, and we are grateful for that,” said the Bulletin of the Atomic Scientists’ Bronson. MacArthur rolled out a three-year, $30 million capstone project to transition Nuclear Challenges grantees to a post-Big Bets future. That provided, among other things, general operating support for organizations, and established a cross-program initiative between Nuclear Challenges and Climate Solutions to provide leadership on the intersecting issues of climate change, nuclear power and global security. 

That being said, MacArthur’s methodical efforts to provide grantees with a long runway couldn’t entirely paper over the fact that the nuclear security field, which has persistently grappled with tepid funder support, was losing one of its largest and most stalwart supporters.

The impact of a giant exiting a field

MacArthur's grantmaking in the nuclear security space well precedes its formal Big Bets program. Since its founding in 1970, MacArthur has given financial support to global peace and security, including grants related to nuclear policy. Those efforts evolved in the 1980s to a more focused initiative to confront nuclear weapons challenges and address the need for new approaches to global stability. MacArthur formally established a program focused on international peace and security in 1984.

Fast-forward to the era of the Big Bets. In 2017, MacArthur began working with the Seattle-based ORS Impact to assess the impact of the Nuclear Challenges grantmaking from 2014-2020. In February 2021, MacArthur published the findings of its assessment. “Overall,” the report read, “the assessment of the articulated Nuclear Challenges strategy established that there is not a clear line of sight to the existing theory of change’s intermediate and long-term outcomes in the Big Bet timeframe.” That same month, MacArthur sent an email to grantees informing them of its decision to wind down the Nuclear Challenges program. In the ensuing weeks and months, staff had Zoom calls with grantees to address their questions and spoke with organizational leaders as needed. 

Speaking on MacArthur’s decision to exit the nuclear security space, Tierney, of the Center for Arms Control and Non-Proliferation, told me, “We certainly weren’t expecting it, and I’m not sure that anybody that I know in the field was expecting it either.”

Leaders I contacted expressed frustration with MacArthur’s decision to exit the nuclear security field, where change requires committed participation from governments, and as such, is often measured in decades rather than years. Even if their wins did not meet MacArthur’s targets, advocates noted important progress in the making.

Arms Control Association Executive Director Daryl G. Kimball said experts and policymakers have been working on reducing global nuclear risk by ceasing production and eliminating stockpiles of weapons-usable material since the 1960s, and that it can be unrealistic to expect paradigm-shifting change within a five- to 10-year time frame. “The prospects of making progress on that particular issue in the near term is not high; it’s very difficult,” he said. 

When it comes to longer-term change, the Center for Arms Control and Non-Proliferation’s Tierney believes the field has made significant inroads and that any analysis of the field should take this incremental progress into account. “Since the Reagan administration,” he said, “there have been a number of arms control agreements and other treaties that have reduced the number of nuclear weapons from over 70,000 to less than 15,000.” 

Some leaders also expressed frustration that MacArthur’s exit would have a disproportionately adverse effect on a nuclear security field that is currently grappling with geopolitical instability on multiple fronts. There are other funders in the space, but few of them can match the breadth of MacArthur’s support. 

“The nuclear reduction space has been historically underfunded, and, naturally, a funder withdrawing their support will cause some disruption and discomfort,” said Dr. Emma Belcher, CEO of the Ploughshares Fund, the San Francisco-based grantmaker committed to eliminating the threats posed by the world’s nuclear stockpiles. Prior to joining the fund in 2020, Dr. Belcher spent nearly a decade leading MacArthur’s Nuclear Challenges program, so she comes to this issue from a unique vantage point. She said via email that the impact of MacArthur’s exit “is not the sole result of any one organization’s decision to leave the field, so much as a reminder of how few funders there are in this space and how critical it is that new funding sources be identified.”

On the criminal justice front, JHA’s Vollen-Katz noted that MacArthur's absence would be felt by organizations in the field, which also faces long timelines as it works toward progress.

“The work we do is on the ground, foundation laying, critically important to prison and criminal justice system reform but not always highlighted or in the public spotlight, and often, it is work that takes many years to yield a particular outcome or change to the system – this is the nature of the carceral system — closed and slow to recognize problems and implement new policies and practices," she said. “Having a funder that understands the value of our work and has partnered with us to strengthen our impact has been important for the organization, the Illinois prison system and the field of prison oversight.”

As far as giving in the broader criminal justice space is concerned, IP’s State of American Philanthropy brief on the topic found that while the field has enjoyed an influx of new donors in recent years, Candid data shows the space received $427 million from domestic grantmakers from 2014 through 2018, comprising just 0.12% total funding for all philanthropic sectors. And while the sector’s top funders during that period included heavy hitters like Arnold Ventures and the Ford and W.K. Kellogg foundations, the biggest of them all was MacArthur, which accounted for 25% of all criminal justice reform dollars. 

“While JHA continually seeks to diversify our funding both in general and to specifically mitigate this change,” Vollen-Katz said, “there is no denying the impact that the loss of such a cornerstone funder will have on JHA and undoubtedly on others as well.” 

“We’ll adjust accordingly”

Now for the encouraging news. Leaders I contacted listed a handful of reasons for being cautiously optimistic, the first one being that MacArthur may not completely walk away from every field. While the foundation made it clear that it’s too soon to say which issue areas it will prioritize going forward, it’s likely that some Big Bet fields will still receive support, albeit with a different approach. Palfrey told me, for example, that he is “confident that we will be in this [climate] space after 2026, although it will not have the same programmatic strategy that we have today — and that goes for the Peace and Security field, as well.” 

Assuming MacArthur continues to fund climate organizations after the big bet winds down in 2026, it would reflect the foundation’s long history providing support to organizations under different programmatic guises. That’s a reminder that during these kinds of shifts at big foundations, for all that may change, there’s often a lot that stays the same.

For example, even back in 2014, when Stasch noted in her annual report that the initiative to strengthen American democracy would come to a close, such funding lives on in other forms. Palfrey told me that the foundation’s support for the Press Forward initiative arose from the recognition that “there's an opportunity for us and others to make very large, catalytic, time-limited investments in local news that could have a huge impact on democracy.” 

We’re also seeing this dynamic playing out in real time as it applies to Big Bets grantees. MacArthur helped the Alliance for Tribal Clean Energy secure a one-year, $1.5 million grant through the Invest in Our Future initiative, a joint funding effort separate from its Big Bets strategy. 

“Not only has MacArthur not abandoned us, they’ve set us up with another pool of potential donors,” Alliance Founder and CEO Smith told me. When I asked her if she thought MacArthur’s climate wind-down would be disruptive for the field, she didn’t hesitate before answering. “They’re not going to abandon an existential crisis and say, ‘We give up,’” she told me. “They’re just going to do it differently.”

As for the nuclear security Big Bet, some leaders I spoke with said that the cessation of MacArthur funding won’t pack an existential punch because its support doesn’t constitute a significant enough chunk of their organization’s budget. “We’re very stable in our operations, and we’ll adjust accordingly,” said the Center for Arms Control and Non-Proliferation’s Tierney, while noting that “we’re keeping our channels open” with MacArthur in hopes it may reconsider its decision to exit the field. 

Ploughshares CEO Belcher said the fund is seeking to fill some of the gap by “carving out a role for ourselves as a ‘field builder’ and backbone organization within the nuclear space.” These efforts include providing supportive services, convening and engaging the fund’s partners and providing organizations with flexible funding. The fund has also adopted what Belcher calls an “intersectional lens to our work and to our grantmaking to ensure that we’re helping to fuse the work of our field and other social justice issues because they are indeed connected.”

Another important funder is the Skoll Foundation, which focuses on countering nuclear proliferation and supporting arms control. Skoll supports Ploughshares and the Carnegie Endowment for International Peace with a current grant looking at issues in the advanced nuclear energy space. “We have no plans at this time to change our work in this arena,” said Bruce Lowry, Skoll vice president of investments, via email.

Lastly, some leaders I spoke with pointed to glimmers of hope on the fundraising front. “We see huge growth in interest from our younger audience members, those younger than 35 years old,” said the Bulletin of the Atomic Scientists’ Bronson. “This is not surprising, given the state of the world.”

Ploughshare’s Belcher considers MacArthur’s Nuclear Security wind-down “a setback for the field and for the individuals impacted.” That said, she is “optimistic that the health of the field will improve, especially as we are seeing, and actively working to support, more collaboration among its players. And this will hopefully attract more funders who are recognizing the urgency and importance of this moment.”

What should we make of the Big Bet approach?

Stepping back from the near-term impacts on these fields and grantees, there’s an underlying question surrounding the wind-down of these initiatives: Is this a good way for a large foundation to make grants? The best answer we can offer is — not always, but sometimes. And it’s a worthy endeavor for a leading funder to try out such concentrated investments in a responsible way and share the results.

In one sense, how you feel about the Big Bets approach will depend on how you feel overall about the idea of strategic philanthropy, which focuses on hitting achievable goals, with progress measured through rigorous evaluation and data. Strategic philanthropy has gotten a bad rap in recent years amid a backlash against overly prescriptive and restrictive giving, but advocates argue that critiques aside, it can be done right, and that big funders have a responsibility to seek out the greatest impact and track results.   

Strategic philanthropy is still the reigning paradigm in most big foundation giving; the main reason we’ve devoted so much ink to MacArthur’s Big Bets strategy is its unique scale and timeline. Foundations make pivots all the time, but only MacArthur wound down over a dozen areas of work from 2015 to 2019 to make room for what turned out to be an aggregate $1.1 billion investment in four areas in less than a decade, all with the intention of those investments being time-limited. For critics of strategic philanthropy, especially, there will be something unsettling about this brand of giving, with huge ebbs and flows of funding in critical issue areas, determined by the calculations of philanthropy professionals and consultants. This is strategic philanthropy on steroids and on a deadline, and the bigger the bet, the bigger the risk of disruption, even failure. 

But what exactly do we even mean when we say “failure?” As is often the case whenever we consider issues related to philanthropy’s impact, this is tricky to define. MacArthur’s clear-eyed evaluation reports of the Nuclear Security and On Nigeria point to ongoing challenges, but also areas where the fields have made encouraging progress. Despite the binary that the word “bet” suggests, success is relative, and that can cause friction between funders and grantees. The main sticking point gleaned from my discussions with leaders is that they simply wished MacArthur would stick around and continue to build on the momentum it helped to generate, and feared that its exit may cause the field to take a step backward.

That gets to another criticism of the “big bet” framing as applied to philanthropy, which is that, in big social problems, progress is slow-going, simply because that’s the nature of difficult problems (see Hewlett President Larry Kramer’s take on this in a 2017 opinion piece in Stanford Social Innovation Review). These are issues that demand long, steady work, and patient financial support for that work. It’s possible that some problems foundations take on simply don’t respond well to concentrated bursts of funding seeking transformative change.

At the same time, the approach may indeed be uniquely tailored for a specific kind of big problem, especially when the clock is ticking. “If one’s issue has greater urgency and there is potential to really deploy society’s philanthropic risk capital to catalyze significant change for the good in ways that make waiting and inertia ethically dubious, such a situation seems ripe for a big-bet approach,” said Amir Pasic of the Lilly Family School of Philanthropy. In an era of global instability when massive, urgent problems keep bubbling up, the Big Bet approach has some appeal.

So how do we know when a problem is right for a Big Bet? That’s perhaps where MacArthur deserves credit for taking big swings like this. Pasic said he hopes that the funder will continue to be open with its findings as the other bets wind down. “The new era of big bets promises more systematic learning that will benefit entire segments and the sector itself,” he said. “This could be an important contribution.”

Finally, the not-so-simple fact that MacArthur has carried such huge infusions of funding in a relatively grantee-friendly way — prioritizing general operating support, less reporting, and big grants even for small groups, as opposed to nitpicky project grants — represents an important step forward for high-dollar strategic philanthropy. It may be years before we know whether these bets paid off for the fields in question, but such practices make it far more likely that they’ve boosted the groups on the ground, instead of merely rolling the dice.