Great news ! It seems promising. It's true that even within effective altruism, factory farming is not funded to the extent it should be, given the super high cost effectiveness compared to most other interventions in other cause areas.
And I really like the DON'T DONATE message - very honest !
Minor question - I noticed that the website states for the climate fund that the same donation will help a lot more animals than the impact fund (over 2x as many - and mostly driven by chickens and pigs). I know the numbers are likely low confidence, but just curious how you're thinking about those, as to me it was unintuitive to have one labelled "impact fund" that straightforwardly looks worse on animal impacts than the climate fund (and also worse on the climate side!). I didn't quite understand why this was happening from looking at the calculations page (though from the charities in each, I definitely have the sense that the impact fund is better for animals!)
Good question Abraham!
The impact fund does help more animals, because it includes the Shrimp Welfare Project, but we recently decided to stop displaying the number of shrimp helped, because for the average donor we think this is counterproductive:
But this means that the number of animals helped that we display for a given donation is lower for Impact Fund than Climate Fund which I agree is confusing. I'll think about what we can do about this. Thanks for pointing it out!
Note: There's also the matter of how much each animal is helped, which is a way that a charity with a lower animals helped per dollar could still be more impactful per dollar. You can see the spreadsheet underlying these impact estimates here.
Thanks! That's useful and makes sense! Appreciate the quick response
I think donor matching is a good idea and this post has a great title- it got me to read the article more than once. And now I want to donate to the bonus fund but I just have one question first:
Do the non-bonus donors get to decide which charity to support within a range of charities, and if so what's in that range?
Hi David, it’s great to hear you’re interested in supporting the Bonus Fund! I’d recommend playing around with the giving widget on the website to understand what donors get to decide, but in short:
They choose both a Favorite and Super-Effective charity to split their donation between. They can choose any U.S registered charity as their Favorite Charity, and they can choose from 6 individual charities (The Humane League, Fish Welfare Initiative, Shrimp Welfare Project, Sinergia Animal, Dansk Vegetarisk Forening, Good Food Institute) or our Impact Fund (a combo of all 6) or Climate Fund (a combo of the last 3 I listed) as their Super-Effective Charity. The more of their donating they allocate to the Super-Effective Charity (as opposed to their Favorite) the larger the bonus they get, incentivising people to give more effectively and causing the vast majority of matching funding to go to the Super-Effective Charities.
You can also click on “More detail on how it works” at https://farmkind.giving/support-bonus-fund for more detail on how the system adds value.
You can contribute to the bonus fund here.
This link sends me to a "No access to this page" error.
Fixed - thanks
Factory farming is one of the most neglected cause areas relative to the amount of suffering it causes. Globally, Farmed Animal Funders estimates that just $200 million is channeled specifically to this issue,[1] while more than 10 billion land animals (excluding insects) are factory farmed annually in the US alone.[2]
Even when it comes to effective altruism, factory farming is a minority within a minority. We estimate that less than 10% of the funds raised by effective giving organizations go to factory farming.[3]
All this despite the fact that proven interventions in the lives of factory-farmed animals remain arguably some of the most cost-effective ways to prevent suffering that we have yet discovered.
The lack of funding has several consequences:
FarmKind’s mission is to increase funding for farmed animal charities by bringing in new donors and donations.
To do this, we’ve built a platform inspired by the innovative work of Prof. Joshua Greene and Dr. Lucius Caviola and their Giving Multiplier platform, tailored specifically to raise money for farmed animal charities. People donate because they feel compassion but also want their donations to be spent wisely and have an impact. FarmKind seeks to meet both these motivations so people can feel good while they do a huge amount of good too.
We work with expert charity evaluators, including Animal Charity Evaluators, to find charities that are super-effective at making the lives of factory-farmed animals better. We help donors give to a curated set of these charities while, at the same time, splitting their donation with their favorite charities. Then FarmKind boosts both donations with a bonus.
We hope that, by increasing funding to these higher-profile and more thoroughly evaluated organizations, we will be able to free up other funders to look at interventions that require more vetting than we currently have the capacity for.
FarmKind was incubated in the first Charity Entrepreneurship Incubation Program of 2024, in April this year. Since then, founders Aidan Alexander and Thom Norman have been working to launch our giving platform as soon as possible.
We have now launched our platform and are receiving donations. You can find us here: www.farmkind.giving
To get to this point so far would not have been possible without the amazing support of a lot of people who want to see a better world for animals. In particular, our platform would not have been possible without Hive’s Douglas Browne, Violet Studios or Every.org. Many others have helped us get to launch, are too many people to list here, but please check out our acknowledgements on our site here.
If you’re reading this post, our platform isn’t aimed at you. We aim to convert new donors to supporting effective farmed animal welfare. If people who would have given to our recommended charities anyway donate through our platform it doesn’t add any value, and what’s more, by using up limited matching funding, donating through our platform hurts our ability incentivise counterfactual donations.
If, however, you’re the type of person who gives to ACE recommended charities already, you may be interested in giving to them via our bonus fund. By donating $1 to our bonus fund to incentivise others to donate to effective charities, you can cause more than $1 in donations, multiplying your impact. See our write up on how this works here. If you have any questions about this, please contact [email protected].
In the RCT that Giving Multiplier is based on, donations to their equivalent of our bonus fund saw a 2.6x return on investment (meaning that each $1 of matching funding causes $2.60 of counterfactual donations to effective charities). It's too early to estimate how the return on investment compares on our platform, but we will report on this when we have conclusive numbers.
If you believe in our mission and want to help out, there are lots ways you can get involved. Below is a list of things you might be interested in, all of which we think would be genuinely helpful to us and our work.
If you’d like quarterly updates on FarmKind you can sign up here.
We shared our reflections on some of the criticisms our Bonus System received here.
Sources:
Number of farmed animals in the US: https://ourworldindata.org/how-many-animals-are-factory-farmed
10% is a conservative estimate based on internal figures we’ve seen from a number of organisations. Giving What We Can's 2020-22 Impact Evaluation reported 9.15%, on average across pledge and non-pledge donations.
I worry that messages like this implicitly double-count impact. A simplified, stylised example would be if you took $1 from Alice and said to Bob "if you donate $1, I will donate the total $2 to charity". Then you tell Alice that she caused $2 to be donated by incentivising Bob, and Bob that he caused $2 to be donated by using Alice's matching funds. But there aren't $4 of impact to go around! The matching structure relies on inconsistent impact attribution, and to the extent it's knowingly inconsistent, that's IMO dishonest, and we shouldn't be doing it.
See also GiveWell's 2011 critique of donor matches (though also they later used them), an old Forum post specifically objecting to Giving Multiplier's messaging (at the time), and various other commentary, usually critical, in the Forum's donation matching tag.
I agree that this is misleading. If you are telling these new donors that this is a counterfactual match, that is another way of saying that if these new donors do not put up money than the funds in the the matching pool will not go to this good cause. Which is not the case: if there was a real danger that these matching funds would go unallocated then the announcement wouldn't be asking us not to donate!
Hi Jeff - thanks very much for taking the time to comment. In the case of FarmKind, however, I think this specific critique is a little wide of the mark. We address this specific concern on our page about the matching fund (just click 'More detail on how it works' for a drop down with a detailed review). Link here.
In short, donating with us determines where the money in the bonus fund goes, including which favourite charity they choose, which super-effective charity they choose, and how much to allocate to each.
More broadly, we've tried to be as transparent as possible about how things work with our entire system. In an ideal world, we'd have loads of information right up front with plenty of footnotes, but we have to recognise that this is going to put off the majority of donors. So, we've had to strike a balance: all the info is there if for those who want to look for it.
But, we're always listening and happy to take on board critiques :)
After reading through FarmKind's materials, I do think my criticism is accurate. FarmKind has the same issues I previously documented with GivingMultiplier. The "bonus" is presented to users as if it (a) will go in part to their favorite charity and (b) is money that would not otherwise be going to help animals, but neither of these are true. The system is fully explained on other pages, as you say, but the typical person going through the site is donating under a false impression of their effect.
I don't think the problem is that it's difficult to explain things transparently without putting people off with verbosity, but instead that the core thing that makes the site work (convincing people to give more by giving the impression of greater counterfactual impact) is misleading.
I appreciate that you're trying to help people give more effectively and improve conditions for animals, but this kind of fundraising is corrosive and does not belong in the EA movement.
Hey Jeff, I just want to correct a couple of false claims: (a) The bonus WILL in part go their favorite charity, as you can see when you step through the donation process (see this screenshot: https://drive.google.com/file/d/175IonBvB7uRDuZUCybJ50njnTMh5NV5n/view?usp=drivesdk). This is true of Giving Multiplier as well. (b) It is not the case that all bonus funds would otherwise go to help animals. We fundraise for our bonus fund from the same donor pool as our regular donors, encouraging them later to “pay forward” the match they received by supporting the bonus fund and encouraging others to donate. For this reason, much of the money in the fund would not have otherwise gone to animals or effective charities. In our case, our bonus fund was seeded by a friend’s birthday fundraiser, where most of the money was donated by their extended family who are not animal people or EAs.
I disagree with your other critiques, but don’t see a productive outcome or use of time in digging into it here, so I just wanted to correct those 2 factual misapprehensions.
Thanks for the response!
I agree that the site gives the impression that part of the bonus goes to the favorite charity, but that isn't usefully true. I explain this in detail in my GivingMultiplier post, and summarize it as "A simpler way to describe this is that it matches whatever portion you choose to give to the effective charity at 50%, and doesn't match your donation to the other charity at all". [EDIT: the FarmKind function is a bit more complex here, sometimes above 50% and sometimes below, but the matched portion to the non-effective charity remains 0%] To take the screenshot case, I think it would be much clearer to describe it to donors as the donor putting $150, of which $90 goes to the favorite charity and $60 to the effective charity, and then FarmKind contributes $30 to the effective charity.
First, the post we're discussing this on is a counterexample. FarmKind is fundraising from EAs, and writes "If you’re reading this post, our platform isn’t aimed at you. ... you may be interested in giving to them via our bonus fund". That is, FarmKind does not want EAs (or other people who already plan to give to help animals effectively) to give through the matching platform, but does want them to give to the bonus pool.
Second, I was trying to make a more limited claim, about what happens to the money that's already been put in the bonus pool. I think we can agree that every dollar donated to the bonus pool is one that will be paid out to effective animal charities regardless of how other donors behave?
On your first point, your way of describing things may or may not be clearer, but it’s not accurate. See my response to Ben Milwood about how the money flows. You may see the two scenarios as being the same in effect, but in that case our comms are equally accurate in describing the effect and more accurate in describing the money flows. We’ve chosen what we believe to be the most clear, intuitive and compelling way to explain things.
On the first part of your second point, yes - some bonus funding money would have otherwise been given to help animals (like anyone convinced by this post), while other bonus funding money (and so far the majority) wouldn’t have. So it is not the case that all bonus funds would otherwise go to help animals, which your original critique suggested was the case. That’s what I wanted to correct the claim.
Regarding your more limited claim, I don’t agree that “every dollar donated to the bonus pool is one that will be paid out to effective animal charities regardless of how other donors behave” because dollars in the fund very literally get paid out to favorite charities that needn’t be super-effective or support animals.
Plus, when thinking about the counterfactual impact of the bonus system, I think what’s relevant is what would have happened to those dollars if the fund didn’t exist - not just what would have happened to them once already in the bonus fund. As explained, many donations to the bonus fund would not have been donated at all were it not for the fund or would not have gone to effective animal charities. And were it not for regulator donors generating demand for bonus funding, we could not fundraise for the bonus fund. The two groups of donors incentivise one another to donate and lead to more total donations to effective farmed animal charities than if the system did not exist. We explain this in our comms. I believe that how our system works is in keeping with the spirit of even the most naive interpretation, in that, whether you’re a regular or bonus donor, your participation in the system leads to more money being donated than would have occurred otherwise.
It’s fair enough that you would have chosen to communicate things differently in our position. Thank you for giving the system some thought and voicing your perspective on how you would choose to communicate things! It’s helpful for us to consider such perspectives as we continuously improve our platform.
Maybe it would be most productive to focus on this limited point:
Lets say I came to you with an offer. I have a pot of money with $100 in it. If you do nothing I'm going to donate it to ACE at the end of the day. If you're willing to donate $50 to ACE, however, then I'm willing to give you $25 from the pot and only the remaining $75 from the pot will go to ACE.
(This offer is not intended to be fully analogous to the FarmKind situation, but to be a simplified version where your "very literally get paid out" defense still applies.)
The net flow of money if you don't take the offer is: $100 leaves the pot, ACE gets $100. The net flow if you do take the offer is: $100 leaves the pot, $25 leaves your bank account, ACE gets $125.
Do you think that in the simplified case it's fair for me to say that I don't agree that "every dollar in the pot will be paid out to ACE regardless of how you behave" because $25 from the pot will very literally be transferred to your bank account?
Similarly, it seems to me that the most straightforward way to describe the flows of money if you take the offer is "The pot will transfer $100 to ACE regardless, and you will additionally transfer $25". My original presentation of the offer, with the idea that some money goes from the pot to your bank account, is adding additional complexity that only serves to make the situation more confusing and potentially convince people to take the offer because they haven't fully thought the situation through.
I agree with your interpretation of this case (except for what the most straightforward way to describe it is), but you seem to be missing the broader point about the interplay between supply and demand for matching funding which means that both groups play a causal role in increasing donations to the favorite and super-effective charities alike. I understand you think the way we’ve communicated this is misleading, not in the spirit of EA or otherwise wrong. This is a valuable perspective, for which I thank you, but we respectfully disagree.
I hope what we do now agree on is that, regarding your comment “the site gives the impression that part of the bonus goes to the favorite charity, but that isn't usefully true”, it IS true that part of the bonus goes to the favorite charity.
That’s all the time I have to spend on this topic. I hope to have clarified some of the facts about how the platform works.
Thanks for the responses!
I'm taking your response to be saying that "part of the pot goes to your bank account" is a fair way to characterize my example offer, but if I've misinterpreted your response let me know?
No I don’t think “part of the pot goes to your account” is a fair way to characterize your offer. I think you may have edited your comment as I was responding to it.
It’s clear we agree on what would have otherwise happened to the money already in the bonus fund at the time of a regular donation. I don’t think we need a hypothetical example to dig into that any further. It’s also clear what we disagree on (please see other comments so I don’t have to state it again). I don’t aim to change your mind on those points, and so I’ll leave things there :)
Hmm, then I'm still confused about why you think this is a fair way to characterize what FarmKind is doing, but not what my offer does. I'm trying to break it down by looking at a simplified case, which is why I think the hypothetical helps?
(While I did edit my comment, it was to add the final paragraph, starting with
Similarly.... I'm pretty sure theDo you think that in the simplified case it's fair for me to say...was in there from the beginning.)(FWIW, it looks like FarmKind doesn't do the exact same matching as GivingMultiplier, and the relationship between bonus size and allocation percentage isn't linear, but it is still always true that the bonus is less than the amount allocated to the effective charity, which is the condition that matters for your argument.)
Good point, thanks for flagging! Here's what the function looks like to me (sheet):
Note that the X-axis is in terms of the fraction of the donor's contribution actually going to the effective charity, and not in terms of the percentages displayed in the tool. For example, when you set the tool to "10%" and put in $1000 it tells you $105 will go to the effective charity and $945 will go to the regular charity. That means $55 of the donor's initial $1000 is going to the effective charity, for a rate of 5.5%, and that is the value I use on the x-axis.
(Part of why I missed this is that the screenshot Aidan provided happens to show the only case where FarmKind and GivingMultiplier function identically)
In your screenshot, you have $150 coming from your donation, and $30 coming from the bonus fund. Your favourite charity gets $90 and the effective charity gets $90. You could frame this as "you are donating $75 to each and the bonus fund is donating $15 to each", or you could frame it as "you are donating $90 to your favourite charity and $60 to the effective charity, and the bonus fund is donating $30 to the effective charity". There's no concrete difference between these in terms of who gets how much money, it's pretty much a matter of interpretation.
I think the thing that leads Jeff (and me) to prefer the latter interpretation is that the bonus is adjusted based on the favourite / effective split so that the amount of money that goes to the favourite charity never exceeds the amount of money coming from the donor -- that is, it is always at least possible to interpret the cashflows in a way that means the bonus fund gave nothing to the favourite charity.
What’s actually happening in the back end is what is laid out in the screenshot: The donor’s donation is split according to their chosen percentage, and then the bonus fund (which is an independent pool of money held by every.org) is disbursed to the favorite charity and the super-effective one.
It's interesting that you implement it that way, but I think the important thing is still the overall net cashflow, regardless of what actual transfers make it happen. The fact that you can't donate $X and get more than $X going to your favourite charity means I don't really feel like my donation is being meaningfully matched.
It's sort of analogous to if a shop says "if you buy this device, you get this peripheral with it for free", but actually they have just set the price of the device to include the price of the peripheral. It's sort of difficult to say that their claim is actually wrong, but it doesn't feel like the most honest explanation of what's going on.
If that’s what it takes for you to feel your donation is being meaningfully matched then it’s another reason this platform isn’t the right choice for you. But that’s a very specific requirement that our platform never claims to meet, and that plenty of folks don’t share with you, as evidenced by existing donations through our platform. Many other donors are excited by the prospect of having both their donation to the favorite and super-effective charity receive a bonus. This is what happens on our platform, and is what’s laid out as they step through the process. No one is donating under any misapprehension that after splitting their donation and receiving a bonus they get more than the total amount they donated given to their favorite charity.
We are not “baiting” people in with the promise to cause more dollars than they donate to go to their favorite charity and then “switching” to a split and boost mechanism. Rather, the platform (as we lay out on our landing page, and repeat throughout) promises to allow you to help fix factory farming while supporting your favorite charity too, and to get your donations to both charities boosted. The platform isn’t about getting more than the total amount you donated to go to your favorite charity (it’s about splitting and boosting your donation) so the fact that it doesn’t do that is a feature and not a bug
Aidan, Ben (I assume) and I aren't commenting because we feel like we're personally harmed by FarmKind. Instead, it's that a core part of the EA movement is bringing clarity and transparency to charity, helping donors understand what the real impact of their donations is, and we're concerned about an effort that seems to be going the other way.
That people are willing to donate through a platform isn't much evidence either way on whether it's misleading: many donation appeals are seriously misleading while bringing in large amounts of money.
That people are willing to donate through a platform that clearly sign-posts that you don’t get >$X donated to your favorite charity if you donate $X split between two charities IS evidence that many donors don’t share Ben’s expectation about how our bonus system should or does work. That’s all I suggested it was evidence for. I’ve only weighed in here to correct false or misleading claims made about how the platform works.
As for whether how the platform works is aligned with EA or not, or misleading or not, I haven’t weighed in because I’m sure it’s clear from our choice to launch this platform that we think this is a good thing to be doing, and that it’s our attempt at doing altruism effectively. It’s reasonable to disagree and I understand and respect your disagreement. I have similar disagreements with many EAs’ approaches, decisions, cause area prioritisation, communications styles and so on. Once there aren’t any remaining misunderstandings about how our platform works, all that’s left is one of those kinds of disagreements. I don’t have much to say about your position except that I respect it, I disagree and I thank you for sharing it. I considered your critique of Giving Multiplier prior to deciding to launch our platform and was grateful to come across this perspective before rather than after making the decision. So thank you again!
[fixed]
Thanks - should be fixed now
Do you think this is an insurmountable problem with the model, or just one that is practically difficult to overcome? I can think of two possible ways to fix it:
Hi Ben, thanks for responding. I think you raise some valid points, we hope that we are avoiding being dishonest as we agree with you that we shouldn't be.
What the standard donor gets is to control where the bonus fund goes. What the bonus donor gets is to help encourage more donations. We do explain this on our site.
One broader point I'd make is that there is a real tension between being very precise and transparent and being concise enough that we won't switch most people off with too much information too soon. We're trying to tread that line, but we welcome critical feedback where we might not be getting the right balance.
While I'm sympathetic to the usual criticisms of donation matching, I don't think your critique applies very well to the quoted sentence as written. Instead, I think its validity comes on the matched donor end (GiveWell's 2011 critique likewise seems to imply that matching works out okay for the matching donor.)
On the matching donor end, they really do get $1 of direct impact plus influence over someone else's $1 of impact. Unless one thinks that influence is worth $0, then it seems reasonable to characterize the combined output as "worth" more than $1. I would prefer the use of increase rather than multiply in the quoted sentence, because the reader may associate multiply with integers more readily than they would associate increase. As a whole, I think the original post fairly conveys to matching donors what outputs they are getting for their money. Thus, I find the stylized example -- in which Alice and Bob are both being promised $2 of impact -- to not track the original post very well.
I also think it's generally OK to calculate ($1 + influence kicker) for the matcher and ($1) for the matched. A strict requirement that all impact credit must equal no more than $2 is not consistent with socially accepted understandings, and there is an degree of flexibility that is non-misleading in a social context.
[numbers/details made up] Suppose I gave GiveWell $1 to run non-matching based ads, and people donated $10 as a result, which GiveWell then regranted to AMF. Both use specially-designated donations to cover administrative overhead. The prorata share of GiveWell's admin overhead is fifty cents, and the pro rata share of AMF's is 25 cents. Moreover, GiveWell and AMF employees indirectly contributed fifty cents by accepting less than fair market value for their work. So the total cost of the "$10 of impact" is actually $12.25. We would not expect GiveWell to tell donors that their $1 was worth only 81.6 cents of impact. Nor would we assign zero impact to me, the admin-overhead donors, or the employees. There's some "inflation," but I don't think anyone has been deceived in this hypo. More generally, as long as the charity is transparent about what the matching donor is getting, and doesn't claim they deserve all of the impact of the matched donation, I don't see an obvious problem as to the matching donor.
(FWIW I find "matching / matched / matcher" confusing, and will stick to Thom's "standard donor / bonus donor" terminology. Sorry if I've responded to you assuming you meant one of these things when you actually meant the other.)
To the extent that influence over the $1 has any value, it's value that is taken from the bonus fund donor. By donating to the bonus fund instead of donating directly to charity, you lose influence over where the money goes. There's still a potential for value creation here if the influence is worth more in the hands of the standard donor than the bonus donor, but I would if anything expect it to go the other way, that standard donors on average tend to make worse choices than bonus donors.
I disagree, I think we should indeed be strict with this requirement. What's socially accepted outside of EA circles isn't a good guide here IMO – after all, almost the whole reason EA exists is because the broader social consensus on how to do good has some pretty serious flaws.
I think the reason to be strict with this requirement is because failure to do so can lead to people choosing worse actions over better ones – e.g. if you're telling your two $1 donors that they're responsible for $1.20 and $1 of impact respectively, then they ought to be willing to pay up to $0.20 of payment processing fees between them to make it happen, but that would ultimately lead to less money going to charity.
(To be clear, when I say "strict" I mean only "any deviation from this is a reasoning error", not "any such errors are unacceptable" or whatever. Mistakes are OK, but this is a mistake.)
oh, I also want to add that:
If all the effective charities have similar levels of effectiveness, then the bonus donor probably doesn’t care about having influence within that subset?
Yes, but then the standard donor doesn't care about having the influence either, right?
No, the standard donor is meant to be a different audience, someone who isn’t seeking to maximise effectiveness - that’s why the post asks EAs not to be standard donors.
My use of non-"standard" terminology seems to have caused confusion; if I understand yours correctly, I think it is the bonus donor who usually gets more than $1 of value. The bonus donor surrenders control over which of six super-effective charities receives his $X. In exchange, the bonus donor gains influence over whether $2X from the standard donor goes to a standard charity or a super-effective one. Given EA beliefs about how starkly more cost-effective its preferred charities are over the median charity, the bonus donor likely views this control-for-influence trade as a net positive unless they have a strong preference among the six super-effective charities. It's the standard donor who is getting the short end of the stick in my estimation.
However, I think "$2 in, $2 out" obscures that mutually beneficial trades of control/influence can occur. The existence of mutually beneficial trades is, after all, fundamental to economics. When we are discussing trades in an economic marketplace, we assign value based on how each trade participant values what they gave up and what they got. If I buy a widget at $1 but would have been willing to pay up to $1.25 for it, we would say that the trade has generated 25 cents of consumer surplus. We wouldn't say that the widget must be assigned the same value on both ends of the transaction, and thus all trades are zero-sum and surplus cannot exist. Applying this model back to matching, it would seem consistent of us to calculate aggregate donor value based on the honestly held preferences of each donor and the true economic substance of the transaction.
So it's possible for a trade to result in more utils under the preferences of both donors and those of the facilitator. Maybe the most extreme example would be a case in which I was planning to donate $1 to Politician Red, and you were planning to donate $1 to Politician Blue, but we both surrendered full control over our donation in exchange for influencing the other to donate the $1 to AMF instead. Or less dramatically, suppose I slightly favor effective animal-welfare charities over effective health ones, while my brother is relatively indifferent between effective and his favored non-effective health charities (but strongly prefers either to any animal-welfare charity). We can compromise on the effective health charity, rather than splitting 50/50 between our first choices.
On those trades, it seems really incongruous to say that there was $2 of impact before, and yet only $2 after. In the me/brother example, you could say that there was only $1.10 of impact pre-trade ($1 for me, 10 cents for my brother) and $1.90 post-trade (95 cents for each dollar spent, since we stipulated that the animal-welfare charity was slightly more impactful). I would roughly allocate that impact as $1.40 for me / 50 cents for my brother. Why? It seems illogical to assign less impact for the donor's own dollar than they would have attained prior to a mutually beneficial trade, and "split the surplus" seems like a reasonable default rule. But the end result is that the trade (which is equivalent in effect to a "match") has indeed increased the impact attributable to both my brother and to me! So, the claim that one can often increase impact by trading control/influence with a donor who would otherwise make suboptimal choices would evaluate as true. And I think that's the core claim that donation-matching orgs are often making, at least to EAs?