Giving Multiplier after 14 months

Written by Lucius Caviola & Joshua Greene

14 Months ago we launched Giving Multiplier to test a new technique for broadening the appeal of effective giving. This post gives a summary of the key results and insights. In short, we fundraised $1.5 million from about 3,500 donations, with most of the funds going to highly effective charities and coming from donors who are new to EA.


Giving Multiplier tests and deploys a technique for encouraging ordinary donors to support effective charities. It’s part of an academic research project. In our preprint paper we report on our studies in more detail.

Previous research has found that it is hard to encourage typical donors to support effective charities. Donors typically prefer to support charities they find personally/​emotionally meaningful, even when they know that other charities are more effective. In many studies we (and others) have found that brief interventions based on arguments have little to no impact on most people’s attitudes and behavior. Here, our strategy is to work with people’s preferences (in a transparent way) instead of trying to displace them.

Giving Multiplier uses two techniques. The first is donation bundling: allowing donors to split their donation between their personal favorite charity — any legally recognized charity in the US — and a highly effective charity recommended by experts. In our experiments, we find that about half of participants (US citizens) are willing to split their donation 5050 between their favorite charity and an unfamiliar highly effective charity. In Study 1 we found that offering a bundling option increases total donations to the effective charity by 76%, compared to only offering donors an all-or-nothing choice between the personal favorite charity and the highly effective charity. Study 2 shows that highly effective charities are especially appealing complements to personal favorite charities when splitting donations.

Subsequent studies show that bundling works because it allows donors to satisfy two competing motivations at the same time, to give with both the “heart” and “head”. Donors primarily want to support their favorite charity, but this preference is relatively scope insensitive (Study 3). Giving $100 to your favorite charity doesn’t feel twice as good as giving $50. This makes room for satisfying the secondary desire to give effectively. By making a split donation, donors get nearly all the satisfaction of giving everything to their personal favorite charity, plus the additional and distinct satisfaction of doing something highly effective (Study 4). Consistent with this, we find that bundle donors are seen as both highly warm and highly competent (Study 5).

The second technique Giving Multiplier uses is a form of donation matching. Donors can get their donations matched at increasing rates for allocating greater proportions to the effective charity. In Study 6 we found that this technique boosts effective donations by an additional 55%. The matching funds are provided by a subset of donors who are willing to support the matching system, a technique we call micro-matching. Study 7 indicated that micro-matching could make the entire donation system financially self-sustaining.


We launched the website in November 2020. The project was funded by a $27,000 EA Funds grant (which did not pay for any of Josh’s or Lucius’ salaries).

We primarily advertised the website through unpaid media coverage and podcast appearances. This included articles in the LA Times, Project Syndicate, MarketWatch, and along with podcast appearances on Waking Up (Sam Harris), Happiness Lab (Laurie Santos), and Mindscape (Sean Carroll). We also introduced a recruit-a-friend system that allowed donors (including all GWWC members) to invite their friends and family members to try effective giving through Giving Multiplier.

A note on matching: On our transparency page, we explain in detail how the matching system works. In contrast to conventional matching systems, ours allows donors to have an additional counterfactual impact in two ways. The first is through influencing which specific charities receive matching funds. The second is by participating in a supply-demand cycle in which the taking of matching funds encourages the provision of further matching funds, which then encourages further counterfactual donations. Since the added impact may be different from what donors would at first think, we require them to explicitly indicate that they’ve understood these considerations before they donate.


Since our launch in late 2020, we have fundraised a total of $1.55 million from 3,500 donations. Of this amount, over $1 million has gone to our recommended effective charities (about $820,000 is estimated to be counterfactual based on donors’ responses). See here for more detailed numbers: https://​​impact. (Once our academic paper is published, we may publish more detailed statistics.)

Our donations came from over 2,200 unique donors (some people make multiple donations). Most of the donors are new to EA. 73% indicated that they did not know about the effective charity they supported. The reception has been very positive. We have received hundreds of positive messages from donors.

38% of donors contributed fully or partially into the matching system, making the system self-sustaining. That is, we didn’t use any external funding to cover the required matching costs. With our current matching rates (which are increased relative to our previous rates), we estimate that a donor who supports the matching system can expect to have a positive return rate of about 50% (factor 1.5) in terms of counterfactual donations to effective charities. (This is calculated by dividing the mean counterfactual amount to effective charities by the mean amount of matching required. See also Study 6 for an experimental approach to estimate this number.)

We have noticed big differences in receptivity across audiences of potential donors. As noted above, our most successful podcast promotions were with Happiness Lab, Waking Up, and Mindscape. By contrast, we’ve received very few donations via Reddit and Twitter, despite many thousands of likes, upvotes and website visits. Our experience indicates that some audiences, in particular altruistically minded people with an interest in science, are orders of magnitude more receptive than others. These observations merit further study in controlled experiments.

Last year, Giving Multiplier received an award from IDEO and the Bill & Melinda Gates Foundation for being an innovative concept in the digital giving space.


The appeal of effective giving may be broader than previously thought. However, most people don’t want to give up completely on causes that they value for reasons unrelated to impact. Renouncing traditional giving, which tends to be about feelings of personal connection, is highly unappealing to most people. Effective altruism often proceeds on the assumption (at least implicitly) that the embrace of effective giving requires the renunciation of traditional giving. And at the level of a given monetary unit that’s true: If you give a dollar ineffectively, you can’t give it effectively. But it’s not entirely true at the level of individual donors, or even at the level of a single donation transaction: by splitting their donations, donors can get the psychological benefits from both effective giving and traditional giving. And our studies show that this simple strategy can substantially boost effective giving in typical donors.

The share of the population that is willing to give effectively, despite not being primarily focused on effectiveness when giving, may be very large. In our studies of the general population, every second person was willing to split their own donation 5050 between their favorite charity and an unfamiliar highly effective charity. (And that’s without matching funds.) This suggests that this approach could scale by multiple orders of magnitude with the right kind of marketing, yielding an extremely large return.

We wish to be clear, however, that we are not claiming that the evidence presented warrants a general shift in EA’s marketing approach. EA has been enormously successful at attracting financial support using familiar arguments urging donors to fully optimize their giving for impact. For early adopters and those with a similar mindset, the classic approach may be the best approach. And, of course, we ourselves were drawn into EA by these classic arguments. Nevertheless, the globally best approach may be to have more than one approach. It’s possible that the outreach strategy applied by Giving Multiplier can broaden the circle of effective giving without crowding out or otherwise undermining the standard EA outreach strategy. In other words, we view Giving Multiplier’s approach as a complement to, and not a replacement for, the standard EA outreach approach.

Many people are receptive to EA ideals but know little about EA and approach it with some reluctance due to competing priorities. We believe that donation bundling offers an easy on-ramp for EA newcomers and sympathizers. Some Giving Multiplier users, we hope, will get more engaged and ultimately become active effective altruists. For these reasons, we intend to keep the website running. It works, needs little maintenance, and is expected to continue raising funds for highly effective charities and introducing people to effective giving.


We are grateful to many people who have helped us make Giving Multiplier possible. This includes Fabio Kuhn for developing the website and Daniel Rüthemann for designing it; Mark Ulrich, Tina Roh, Santi Hernandez and the team at; Peter Singer, Charlie Bresler and the team at The Life You Can Save; Luke Freeman and the team at Giving What We Can; Jim Bobowski, Buddy Shah, and the team at GiveWell; Benjamin Lipinski, Marta Krzeminska, Chris Lloyd, Joe Brownrigg, Marka Ellertson, Emma Gray-Starcevic, Vaidehi Agarwalla, Kate Yuan for marketing advice; Ari Kagan, Nick Fitz and the team at Momentum; Sam Harris and Will MacAskill; Duncan Peacock and the TED Mystery Experiment; Laurie Santos and the team at the Happiness Lab Podcast; Sean Carroll and the team at the Mindscape Podcast; Stefan Schubert, Joshua Lewis and Fiery Cushman for providing feedback on our manuscript; EA Funds; and many others.