Effective altruism, tithing, and a principle of progressive giving

ABSTRACT

How much should someone contribute to trying to prevent unnecessary deaths and severe hardships? MacAskill, Mogensen, and Ord propose tithing for most of the rich (as measured by income), which has been influential in the effective altruism community. My aim in this article is to contribute, through amending their proposal, to their important project of searching for a weak or very weak principle of sacrifice that would still revise upward how much money goes to the most effective organizations. I do so by presenting four objections to their argument based on demandingness, fairness, net wealth, and historical and contemporary injustices. Then, I show that a principle of progressive can overcome these objections and better fits the reasons MacAskill, Mogensen, and Ord give in favour of their principle than their proposed operationalization of tithing.

KEYWORDS:

• Tithing
• effective altruism
• progressive giving
• Peter Singer
• over-demandingness objection
• William MacAskill
• Toby Ord
• Andreas Mogensen

Introduction

Many in the effective altruism community and beyond endorse some form of tithing. For instance, the NGO Giving What We Can, urges members to take a pledge to give at least 10% of their income to effective charities, and more than 8,000 people have signed the pledge (Giving What We Can n.d.). Tithing is not a new idea. Judaism requires giving at least 10% of one’s income to charity (Singer 2009, 21), and other major religions make similar demands (Singer 2009, 19–22). However, William MacAskill, Andreas Mogensen, and Toby Ord develop a novel defence of a version of tithing as a giving floor that by design is supposed to not be overly demanding (MacAskill, Andreas, and Toby 2018, 179). Their proposal is this:

MacAskill, Mogensen, and Ord’s “Very Weak Principle of Sacrifice”: “Most middle-class members of affluent countries ought, morally, to use at least 10% of their income to effectively improve the lives of others” (MacAskill, Andreas, and Toby 2018, 179).

I adopt MacAskill, Mogensen, and Ord’s proposal as at least partially representative of the effective altruists who support a giving floor, measured as a percentage of income, to the most effective organizations. I do so because it is the most developed defence of the idea, by some prominent effective altruists, of which I am aware.

I argue that the reasons they give in support of a Very Weak Principle of Sacrifice better fit a principle of progressive giving instead of a tithing floor, and that there are other reasons to prefer a principle of progressive giving to their Very Weak Principle of Sacrifice. I support their project of searching for a very weak principle of sacrifice that would do a lot of good if adopted. In the process of making this argument and contributing to their important project, I raise several objections to their arguments. One objection, the ‘demandingness objection,’ shows that the over-demandingness objection likely applies to more people than they recognize in the top 50% of income earners in wealthy countries. The second objection, the ‘action guiding objection,’ suggests their principle is insufficiently specific to be adequately action guiding for some, despite its ostensible precision. These two objections interact: either their Very Weak Principle of Sacrifice is likely overly demanding for some, or it is insufficiently action guiding. The third objection is based on the principle that everyone in the top 50% of income should not have the same floor, defined as a percentage of income, which they are required to donate. I call this the ‘flat floor giving percentage objection.’ The fourth objection, ‘the net wealth objection,’ is based on excluding net wealth as a measure by which to assess how much someone should give. Wealth inequality is even more problematic if one attends to historical injustices as reasons for wealth inequality. The net wealth gap is on average vastly different between racial groups such as Black and White Americans, which is at least partially because of historical wrongs such as slavery. Together, these objections suggest a principle of progressive giving, such as one that Peter Singer supports in some of his writing (Singer 2009, chap. 10), better fits the reasons MacAskill, Mogensen, and Ord give in support of their Very Weak Principle of Sacrifice.

Before making these arguments, I highlight some definitional issues because they become important below. First, MacAskill, Mogensen, and Ord’s definition of the middle class is not the middle 50% of earners. Rather, they identify the middle class as only those in the top half of the income earners of rich countries (MacAskill, Andreas, and Toby 2018, 180). Second, they do not include everyone in the top 50% of income earners in rich countries. They make an exception for those with ‘unusually high costs of living, such as those with a disability that requires significant ongoing healthcare’ (MacAskill, Andreas, and Toby 2018, 180). Third, they use income to measure purchasing power. Income is how much money one earns in a given time period, typically measured monthly or yearly. There are other important ways of measuring property rights and purchasing power. Another important measure of purchasing power is net wealth (wealth for short). This is the worth of one’s total assets minus total liabilities. Finally, they write ‘at least’ 10% of income (MacAskill, Andreas, and Toby 2018, 179). They leave open the possibility that some should donate more than 10% of one’s income, but they do not argue that their principle requires anyone to give more than 10%.

What positive reasons do they give in defence of this proposal? They provide two main reasons in defence of their principle: (1) it would be far less demanding and (2) would do far more good, than many intuitively believe (MacAskill, Andreas, and Toby 2018, 180, 183–96). They state that ‘it is very hard to argue that a principle requiring that much [tithing for most of the top 50% of income earners in wealthy countries] would be too demanding’ (MacAskill, Andreas, and Toby 2018, 181). For the majority of those in the upper 50% of income earners in wealthy countries, they argue that ‘giving financial resources is not particularly onerous, far less onerous than we intuitively believe’ (MacAskill, Andreas, and Toby 2018, 180). They claim that ‘[f]ollowing this principle would have small or no costs to one’s well-being’ (MacAskill, Andreas, and Toby 2018, 200). Second, donating 10% of one’s income is already far more than most people donate, so, if they donated to highly effective charities, it would result in more good than current reality (MacAskill, Andreas, and Toby 2018, 179, 181). For instance, the charity evaluator GiveWell (GiveWell 2021) calculates that donating just $4500 (updated to their latest figures, from 2021) to the most effective public health charity is likely to save one person’s life in expectation (MacAskill, Andreas, and Toby 2018, 181). They support these claims by drawing on empirical literature from economics and psychology that demonstrate the psychological benefits of donating, the relatively small decreases in wellbeing for the wealthy from having slightly less money, decreasing marginal utility of money, and the large positive impact of donations for the worst off (MacAskill, Andreas, and Toby 2018, 183–96). They note there is nothing magical about exactly 10% of one’s income. Rather, they think that donating about 10% of income for most in the upper 50% of the income bracket should be easy.

The over-demandingness objection

MacAskill, Mogensen, and Ord’s proposal is at least partly formulated to avoid an objection (MacAskill, Andreas, and Toby 2018, 178–79) raised by critics against Singer’s strong or moderate principles of sacrifice (Singer 1972, 231). Singer famously argued that ‘if it is in our power to prevent something bad from happening, without thereby sacrificing anything of comparable moral importance, we ought, morally, to do it’ (Singer 1972, 231, emphasis added). His moderate principle is ‘if it is in our power to prevent something very bad from happening, without thereby sacrificing anything morally significant, we ought, morally, to do it’ (Singer 1972, 231, emphasis added).

One of the main critiques of Singer’s principles is known as the over-demandingness objection and is also a well-known critique of utilitarianism (Murphy 1993, 268; Arneson 2004; Cullity 2004, chap. 6; Smart and Williams 1973, 108–18). The basic idea of the over-demandingness critique is that of fundamental importance to liberal individuals is a ‘robust zone of indifference’ (Fishkin 1982, 23), whereby we should be allowed a large area of personal freedom unrestricted by moral prohibition or positive duty, as long as one does not harm others (Mill 1859). Singer’s first principle would curtail liberty more drastically than the second, but if taken seriously, both would require major revisions to commonsense morality. Singer acknowledges this (Singer 1972, 235–36; 2009, 18–19). I do not take a position on whether we should act in accordance with one of Singer’s principles. Rather, I engage with one response to over-demandingness objection because many people take some version of it seriously and yet almost no one acts in accordance with Singer’s ‘moderate’ principle.

I will argue that donating 10% of one’s income for someone who earns slightly more than the median income is not likely to meet the principle of very weak sacrifice, even if they do not have a disability that requires costly health care. That is, their principle likely does not meet their aim of overcoming the demandingness objection for everyone they ostensibly want to include. What should count as a cost? MacAskill, Mogensen, and Ord define the demandingness objection in terms of requiring too great a sacrifice of ‘individual well-being or individual self-interest, as opposed to moral autonomy … or the pursuit of individual projects and commitments’ (MacAskill, Andreas, and Toby 2018, 182). They defend this account of well-being by appealing to intuition (MacAskill, Andreas, and Toby 2018, 182).

There are problems with a purely subjective view of well-being. Christian Barry and Holly Lawford-Smith highlight this in their discussion of assessing when one’s duty to assist is discharged (Barry and Holly 2019). Barry and Lawford-Smith argue there is a problem with the subjective well-being means of assessing costliness (Barry and Holly 2019, 152–54). As they put it, a miser could become distraught by giving a little to effective organizations, but a virtuous doctor could be devoting her life to treating the poor in tough conditions in a developing country, but suffer no psychological costs because she is living her dream (Barry and Holly 2019, 152). Whereas it seems clear that the doctor is discharging her duty to assist whereas the miser is not, a subjective account fails to capture this because of the perceived cost differences. A subjective view of well-being could also create loopholes by allowing people to falsely claim that giving a small amount of their money away is highly demanding to them. Instead of such an account, Barry and Lawford-Smith suggest an ‘(admittedly rough) shared understandings of how people should reasonably be affected by different material sacrifices … based partly on what we think most people do in fact find onerous’ (Barry and Holly 2019, 156). To accommodate such concerns, MacAskill, Mogensen, and Ord later return to the discussion of how to assess costs to argue that their thesis would also hold for objective list theorists (MacAskill, Andreas, and Toby 2018, 197). However, Barry and Lawford-Smith’s objectives are largely persuasive, and hence I adopt their view that costs can include a plurality of goods, including time, money, health, etc., and that they should be assessed by an objective standard of how a reasonable person would likely be affected by contributing to preventing deaths and serious harms (Barry and Holly 2019, 156). Despite these concerns, I think subjective accounts of well-being should count to some extent, for several reasons. One is that how one feels intuitively seems to matter. Second, it provides a way to check whether objective lists of goods capture much of what people report as actually contributing to their wellbeing. As such, either account of wellbeing could generally likely be used here to address the relevant issues.

To understand why MacAskill, Mogensen, and Ord’s proposal is not a very weak principle of sacrifice for all they ostensibly include, consider the purchasing power of someone in the top 50% of national income earners in New York City (NYC). The median real individual US income in 2021 was approximately $38,000/year (Federal Reserve Bank of St Louis n.d..). Imagine someone earning slightly above this in NYC, a secretary at a school. Let’s call him that. Let’s assume the secretary’s take home income is $40,000/year, or $3,333/month (NYC Department of Education 2019). The median rent for a one bedroom apartment in NYC in 2019 was approximately $2,700 (Kolomatsky 2019). The average cost of centre-based infant child care in New York state is about $15,000/year (Zillman 2018). Of those under 30 years old, approximately 50% of US college graduates have student debt, with a median debt of college graduates (with no further education) of $25,000 (Cilluffo 2019). Of course, one could get a studio apartment, move in with a partner, roommates, parents, other family, or live outside NYC. But just paying for rent, childcare, utilities, health care, public transportation, student debt, and groceries would leave the secretary with little to nothing left at the end of the month. MacAskill, Mogensen, and Ord might require this person to give away at least $333 each month. In fact, tithing might even violate Singer’s moderate principle because many reasonably believe that being able to save a little money is ‘morally significant.’ Saving may be especially morally significant in a country such as the United States where financially ruinous health care costs may be one unlucky disease or accident away. In this situation, tithing for some in the top 50% of wealthy countries may impose a demanding risk of poor health or financial misery unless and until one has personal savings or can depend on familial support.

One response MacAskill, Mogensen, and Ord might make to this claim is that demandingness depends on the goods and costs at stake, and that saving costs in big city life may be demanding but the good that would be accomplished by donating far outweighs the annoyances of cost cutting (MacAskill, Andreas, and Toby 2018, 181). As they write, ‘whether a moral theory or duty is too demanding depends on two things: the cost to the agent of the actions required by that duty and the size of the moral stakes at issue. If the stakes are high, morality can be very demanding, without being too demanding’ (MacAskill, Andreas, and Toby 2018, 181). I think they might be right that someone making $40,000 in NYC should try to live frugally, renting a studio apartment outside of a popular neighbourhood, avoiding expensive nights out, and perhaps sacrificing savings to donate to effective charities. But it is doubtful that many people would consider such actions a very weak sacrifice, especially if they must pay for student loans, childcare, and other typical expenses. Another way MacAskill, Mogensen, and Ord could respond is to modify their principle to include only those in the top 50% of income earns relative to the area where one lives.¹ This indeed would increase the amount one would have to earn in a place like NYC to meet the cut-off, and hence would neutralize this objection. Or they might suggest that the excessive costs clause in their original formulation already accounts for such a situation. Perhaps this is something like what they had in mind (I discuss this further below).

There is a separate reason why giving for those similarly situated to the secretary may be more demanding than these authors discuss if one uses the same measure of wellbeing as MacAskill, Mogensen, and Ord do. They assume ‘that donating 10% of our income is like earning 10% less’ (MacAskill, Andreas, and Toby 2018, 187). They then question this assumption. But they do so only by asking whether giving may increase a donor’s happiness, not by asking whether it might decrease happiness of the person giving more than simply comparing two different people on an income scale. That is, they compare person A with person B, who makes 10% less than A, and conclude that a loss of income decreases the average American’s happiness by about 0.1 out of a scale of 10 (MacAskill, Andreas, and Toby 2018, 186). But prospect theory (Kahneman and Tversky 1979; Kahneman 2011, chap. 26) suggests they omit a way that giving may make people feel worse. The basic finding known as prospect theory is that losing some amount of money feels worse than gaining the equivalent amount. Because it is about gains and losses, one should not compare different people of different income levels to determine likely differences in life satisfaction. If someone sees giving as an onerous obligation rather than a joyful opportunity, she may (temporarily) feel worse than the person at the equivalent income level who gave up nothing. As MacAskill, Mogensen, and Ord note in a discussion of the limitations of a study they quote showing that those who give on average report high levels of happiness, ‘nobody was asked to spend money that they had already planned to spend for their own purposes’ (MacAskill, Andreas, and Toby 2018, 188). There is no research of which I am aware where the investigators analyse individuals giving 10% or more of their income away and control for the preferences of the small minority of society who does this already. Whether the positive feeling of giving 10% outweighs the loss of purchasing power is likely to depend on numerous factors, including one’s resulting purchasing power (Rubaltelli et al. 2020), the amount of time after one donated one is asked about well-being, and one’s position of relative wealth compared with others after giving. The same problem of using a subjective assessment of wellbeing arises again here as I noted above (Barry and Holly 2019, 152–56). Given the vast differences in purchasing power parity (PPP) which they note (MacAskill, Andreas, and Toby 2018, 191–95), this would not likely have a significant impact on the costs and benefits, but it would likely tip the scale a small amount against their position.

These arguments suggest that MacAskill, Mogensen, and Ord’s proposal likely fails their aim of developing a principle that can overcome the over-demandingness objection for as large a segment of the population as they claim. For those living above but close to the median income in major cities with high costs of living, donating 10% of one’s income might be demanding. Indeed, it might even fail to meet Singer’s moderate principle of sacrifice. Whether they would include the secretary in the exempt category is unclear, which raises a related but distinct objection.

An action guiding objection

One might object that perhaps I am being uncharitable in my reading of MacAskill, Mogensen, and Ord’s because they mean to include individuals such as the able-bodied secretary in the group they exclude from the tithing duty. There are several reasons why they probably do not mean to imply this. They devote a sentence and one example to explaining what might count as ‘unusually high costs of living’, namely ‘those with a disability that requires significant ongoing healthcare’ (MacAskill, Andreas, and Toby 2018, 180). They do not provide guidelines for how to determine if someone has ‘unusually high costs of living’ (MacAskill, Andreas, and Toby 2018, 180). But they write that ‘[e]ven if only half of all people in the United States abided by this principle, an additional USD 612 billion per year would be donated’ (MacAskill, Andreas, and Toby 2018, 179). Presumably, then, they had in mind only rare cases.

But this uncertainty underscores that their proposal suffers from action guiding imprecision because ‘most’ people in the top 50% of income could mean almost everyone in that group or just above 25% of the population. If this proposal is meant to be able to identify relatively precisely for whom the demandingness objection is inapplicable, it is likely too vague. If they intended to exclude a sizable portion of the 50% from the duty to at least tithe, it raises the question of why they selected the 50% cut-off, and not say only the top 40%, third, or quintile of income earners, or tied income to local purchasing power.

This is especially problematic if the proposal is meant to persuade the undecided of those in the top 50% of income earners in wealthy countries to tithe because of a finding in psychology. People have a predilection to underestimate the disposable funds those richer than them feel like they have (Berman et al. 2020). As Jonathan Berman, Amit Bhattacharjee, Deborah Small, and Gal Zauberman put it, people generally pass ‘the giving buck to the wealthier’ (Berman et al. 2020). We generally think those richer than us should give more and can do so more easily than those richer individuals believe. The imprecision of the Very Weak Principle of Sacrifice allows someone to tell themselves that they should be excluded from the duty because it is demanding for them, but not for wealthier people. Only with a more action-guiding principle could many of us know whether this exemption applies to us.

The unfairness of a flat floor giving percentage objection

The ‘flat floor giving percentage objection’ relates closely to the first objection because of how demanding it is to different people relates to the fairness of that demand. MacAskill, Mogensen, and Ord favour a flat percentage of income as a floor for nearly everyone in the top 50% of income earners rather than another way of operationalizing a principle of weak or very weak sacrifice. It is unfair to set the giving floor the same for the secretary, the doctor, and the mega-rich for several reasons. One reason is because there are similar although not identical fixed costs of living.

To understand the specifics, consider those on the other end of the top 50% of the income spectrum, those in the top 1%. In the US, the top one percent are those making at least $500,000/year as of 2019 (Bloomberg.Com 2019). Let’s take someone who’s making $300,000 after taxes and call this person a surgeon. She takes home $25,000 each month. Giving 10% of after-tax income requires her to give away about $30,000/year. She’s left with $270,000 per year. Suppose she spends $5,000/month on ‘basic’ living expenses (rent, utilities, groceries, transit, etc.). Before donating, this would leave her with $240,000/year of disposable income ($20,000×12). After giving away $30,000, and covering all of her ‘essentials,’ she would still have $210,000 ($17,500/month) in disposable income.

The point I want to make from this financial comparison regards the fairness of a flat percentage of income proposal for giving. The secretary is middle class (traditionally defined), whereas the surgeon is very wealthy. This has a direct implication for whether donating 10% of income for both meets the ‘very weak principle of sacrifice.’ By an objective standard, the secretary would have to sacrifice much more in adjusting his lifestyle to meet the 10% donation requirement than the doctor. At the very least, it could entail some rearranging of his life and making some sacrifices that could decrease his current or future wellbeing or self-interest. Conversely, the surgeon would very likely not have to make any (or only very minor) changes to her life if she donates 10% of her income. Demanding more from one group of people than another requires some reason or justification for such a claim. The 10% rule provides no such justification, even if it remains silent on whether the super-rich should give more. In contrast, a progressive principle of giving would account for such differences so that the ease of donating would be similar across income (and wealth) levels.

The net wealth objection

Next, consider the ‘net wealth objection.’ MacAskill, Mogensen, and Ord write only about income. Singer focuses on income too, both for the organization he founded to promote giving, The Life You Can Save, and in his giving proposals (Singer 2009, chap. 10). To gain insight into a problem with using income to assess giving, take a hypothetical example. Suppose a super-rich person keeps all of her wealth in a combination of properties and a bank account that pays no interest, and has no other source of income. Suppose this person has the wealth of Bill Gates. She’d be one of the richest people in the world, whose net worth would be estimated at around $100 billion. Despite her wealth, in such a scenario MacAskill, Mogensen, and Ord’s proposal would not require her to donate anything because she has no income. Surely this is mistaken. Gates’s and other billionaires’ wealth must bestow a special responsibility on them to give more, both in absolute and percentage terms, than others who have less. Gates and other ultra-high net worth individuals have pledged to give away at least 50% of their net wealth over their lifetimes (http://givingpledge.org). Still, this seems like a low percentage for the super-rich.

One might object to this unrealistic hypothetical example because many and indeed probably all super wealthy individuals have an income, so long as one includes interest and dividends. But it is a useful example because it highlights that focusing exclusively on income would miss the vast amount of purchasing power of the (super) rich. It’s difficult to overstate contemporary global wealth inequality. Gabriel Zucman finds that ‘In most countries the share of wealth owned by the bottom 50% is close to 0%’, whereas the top 10% in the US, China, and Europe own about 70% of the wealth (Zucman 2019, 21). Several years ago, the top 400 people in the US had a higher net wealth than the bottom 60% of adults – some 150 million people (Ingraham 2019). The top 0.1% owns more than the bottom 80% (Ingraham 2019). Globally, ‘wealth is substantially more concentrated than income’ (Zucman 2019, 21). Furthermore, because of US tax law, many of the superrich pay a much lower percentage tax on their salary than those closer to the median US income. Warren Buffet reported in 2011 that the previous year he paid about 17% of his income in taxes (Buffett 2011). But he estimated that the average amount his employees would have to pay in income tax was 36% (Buffett 2011). The 10% rule would require Buffet to donate a larger percentage of the after-tax amount to charity than his employees paying double the percentage of tax that he does, but it is silent on whether Buffet can keep an overall higher or equal percentage of income as some who earned a huge amount less. Even if the principle concerns 10% of pretax income, Buffet would still be paying in tax and donation about half, as a percentage of his income, of what his employee would have to give up, according to the 10% rule (For Buffet: 100–17 = 83. 10% of 83 = 8.3. 83–8.3 = 75.7; for his employee: 100–36 = 64. 10% of 64 = 6.4. 64–6.4 = 56.6). In short, restricting a giving principle to income arbitrarily omits a sizable portion of the wealthy’s purchasing power.

Another reason that focusing solely on income is problematic is that historical and contemporary injustices have contributed to contemporary wealth inequality. Take the wealth gap between Black and white Americans as an example. The average white American has about 6× the wealth of the average black American (Derenoncourt et al. 2022). Racism, from slavery through Jim Crow to current discrimination, plays the predominant role in explaining this wealth gap (Derenoncourt et al. 2022). Yet a proposal like MacAskill, Mogensen, and Ord’s takes little account of such inequalities based on historical injustices. To be more precise, the objection here is that because Black and white wealthy individuals (in the top 50% of income earning in wealthy countries) who earn identical incomes would, on average, be starting from vastly different cushions of wealth grounded in historical and contemporary injustices, it is unfair to have the same baseline donation requirements.

MacAskill, Mogensen, and Ord might reply that their views account for such difficulties because of their escape clause based on ‘unusually high costs of living’ (MacAskill, Andreas, and Toby 2018, 180). If this is based on financial costs alone, as they seem to imply, this doesn’t account for the objection. Assume the Black American and the white American have the same costs of living and the same incomes. The difference is their precariousness and the added psychological burden of that precariousness for the Black person. A reserve of wealth allows for a variety of advantages from psychological security to decreasing the risk of bad outcomes from a loss of income from unemployment or disability, such as foreclosure, homelessness, or other ills. Basing a giving principle on income alone ignores such historical and contemporary injustices and risks, allowing them to fester.

A progressive principle of giving could account for such disparities in wealth in two ways. First, as I argued in the previous section, it would demand more of the wealthier. Second, it could allow those who have less wealth to save more for a rainy day. A precise way to fairly calculate these figures is beyond the purview of this paper, but that does not diminish the important point that it would allow and indeed encourage such nuanced accounting of various means of purchasing power and costs.

An amended proposal: a progressive giving principle

There is a way to overcome these objections and meet the laudable goals of MacAskill, Mogensen, and Ord to revise upward the resources devoted to the most effective organizations at (very) little to no cost to someone. I first explain the sort of principle of progressive giving that I have in mind. Next, I explain why it can overcome the four objections that I raise against MacAskill, Mogensen, and Ord’s principle. Then, I add several additional reasons why such a principle is preferable to theirs.

A progressive giving principle requires a wealthier person to give more (as a percentage of wealth) than someone who is poorer, holding everything else equal. That is, everyone should, morally, give at least that percentage of her net wealth, time, or other resources for which she would have to make a (very) easy sacrifice. (This is similar to Barry and Øverland’s ‘Minimal’ Principle of Sacrifice (Barry and Øverland 2016, 20).) I focus on monetary donations because it is easy to illustrate the differences and, for many, it is likely the best way to operationalize the idea, but it would not necessarily require monetary contributions from everyone. Like progressive taxes, there would be marginal increases in giving to avoid disincentivizing earning more. For instance, if one went from donating 5% of $60,000 to $100,000 of income, then only on that amount >$100,000 would the donations increase to say 7%, and say 20% >300,000. I leave open how exactly to operationalize a principle of progressive giving because, as I discuss below, I think a variety of costs and means of contributing matter and as such there is not an easy and universally applicable set of figures that can apply to everyone. Instead, I will provide examples of what I have in mind, but with the caveat that they are guidelines and not definitive numbers.

What should count as an easy sacrifice? A principle of progressive giving allows for different views about how to define costs. This is a feature, not a bug, because it allows for reasonable disagreement over how to define costs. One way to operationalize costs is to follow Barry and Lawford-Smith, who define costliness objectively as a reasonable person would likely assess it (Barry and Holly 2019, 156), based on what Garrett Cullity calls aggregative assessments (Cullity 2004, 82–84). This combines all relevant costs, rather than comparing the marginal cost (of the person sacrificing) and marginal benefit (to the beneficiary). An easy sacrifice is one in which the donor could generally continue to have a quality of life similar to one’s pre-donation life.

To assess where to draw this line in relation to giving, first consider which principle might fit Singer’s more recent and realistic proposal. Singer has attempted to provide realistic alternatives to his two 1972 principles in several later publications (Singer 2006; 2009, chap. 10) and on a website that he supports (https://www.thelifeyoucansave.org/take-the-pledge). Someone making (pre-tax) $300,000 per year would be required to give 6.6% of income, and someone making (post-tax) $300,000 would have to give 10% of pre-tax income or about $50,000/year. This would still require only a small lifestyle adjustment for almost everyone. The doctor could easily give more than that, and still live extremely comfortably, as I show next.

But if such a proposal is minimal, what would then count as an easy sacrifice? Suppose that instead of giving away 10% of her total after tax income ($30,000), she donated 0% of her first $50,000, 10% from $50,000 to $75,000 ($2,500), 20% between $75,000 and $150,000 ($15,000), and 33.3% above that (~$50,000), or $67,500 in total. That leaves her with $232,500 per year or >$19,000/month. By any reasonable, objective standard, that is still living large. What about how the doctor would very likely feel? Again, we don’t know because there have not been studies testing this. But if we use the imperfect approximation of comparing different people, the evidence suggests that there is a log-linear relationship between income and wellbeing, meaning that for each doubling of income, there is a unit increase in wellbeing (Deaton 2008; Stevenson and Wolfers 2013). The data suggests that after giving (discounting the positive feeling someone gets from giving), someone like the doctor is still very likely to be happy (Stevenson and Wolfers 2013, 600–602). More recent research suggests that money affects people’s happiness differently, with top the 80% of happy people continuing to increase in happiness as income rises and the bottom 20% flattening off above about $60,000–90,000 in income (Killingsworth, Kahneman, and Mellers 2023).

What should the secretary and mega rich give? Depending on the secretary’s situation and other obligations, he might reasonably donate nothing if he currently has student debt and child care expenses, or one or a few percentage points of his income if he’s debt free and living with a partner in a modest apartment. Ultra-high net worth individuals could and therefore should easily donate the vast majority of their income or wealth. If Gates or Bezos donated 99% of their wealth, they would still be billionaires, do an immense amount of good, and still be exceptionally well-off.

There are numerous advantages of a principle of progressive giving compared with a tithing floor. I discuss the advantages in the order of the objections I present in the previous part of the paper and then add several more reasons why a principle of progressive giving is preferable to MacAskill, Mogensen, and Ord’s principle.

First, a principle of progressive giving avoids triggering the over-demandingness objection that could reasonably apply to middle class people, a stated but ultimately unrealized goal of MacAskill, Mogensen, and Ord’s principle. It avoids this objection because the sliding scale would be operationalized in a way that accounts not only for income but also includes other costs, which almost always vary over one’s lifetime (e.g., with childcare, promotions, unemployment, inheritance, etc.).

One could object to operationalizing a principle of progressive giving in the following way: giving away a large amount of one’s wealth could be psychologically demanding for the rich and so my proposal would not in fact overcome the demandingness objection. There are several replies to this objection. One is that the demandingness objection relates to the overall good likely to be accomplished compared with the cost, as MacAskill, Mogensen, and Ord note (MacAskill, Andreas, and Toby 2018, 181). If we follow MacAskill, Mogensen, and Ord in their interpretation of this aspect of the demandingness objection, giving away large amounts of money could still be psychologically costly for the very rich, and the over-demandingness objection would not be triggered if the good that such donations effect would be very large, as they would be. A second reply turns on the account of costliness one uses. As the discussion of Barry and Lawford-Smith shows, a purely subjective theory of wellbeing can be problematic when assessing costliness. As they argue, an objective standard of giving may be preferable to a purely subjective cost (Barry and Holly 2019, 152–56).

Second, it is more action guiding than MacAskill, Mogensen, and Ord’s proposal for several reasons. One way that it is more action guiding is that it provides guidelines for a larger portion of the population than MacAskill, Mogensen, and Ord’s proposal. This is because it provides some guidance for the vast majority of the world’s people who are not in the top 50% of income earners in rich countries. It encourages these individuals to contribute a small percentage of their income, wealth, or time to ameliorating some of the world’s gravest challenges. Although I focused on giving money to the most effective organizations, this is not the only way to satisfy this principle. How else might this principle be implemented? A working-class individual in Philadelphia could volunteer to help fundraise for a highly effective organization, or a destitute person in rural Kenya could contribute sugar cane to be sold at a Harambee (fundraiser) for a student’s school fees. Perhaps these are the most effective things these individuals could do.

Furthermore, in one plausible interpretation of the principle, adds precision to who should have to give how much for those in the top 50% of income earners in wealthy countries, and provides details beyond what MacAskill, Mogensen, and Ord suggest may nullify their tithing principle (namely ‘unusually high costs of living’ such as for health care). I admit that a principle of progressive giving cannot provide an exact figure that everyone should donate. Rather, my claim is that a principle of progressive giving is more action guiding than MacAskill, Mogensen, and Ord’s proposal, and hence an improvement, given the justifications they invoke in defence of their principle. For instance, a website Peter Singer supports (https://www.thelifeyoucansave.org/), has a simple calculator where one can enter one’s income and it provides a suggested level of donation. A more detailed online calculator, which accounts for various costs (healthcare, childcare, housing, debt, etc.), and net wealth could provide a closer approximation to the principle I have in mind. Similar online calculators are available to estimate one’s carbon footprint. It may be more practically action guiding for some given what we know about the psychology of who thinks of themselves as rich and how much those richer than them should give (Berman et al. 2020). If someone has unusually high costs of living, MacAskill, Mogensen, and Ord allow that person not to tithe. But they are silent on what that person should give. Conversely, a principle of progressive giving provides guidance.

Third, it avoids the unfairness of a flat giving floor because a principle of progressive giving by definition requires people with different purchasing power and costs donate different amounts. Under a principle of progressive giving, someone closer to the median income and median net wealth and typical costs would give less than someone in the top quintile of income and net wealth and typical costs. The key point is that the floor is adjustable. This would allow a better reflection of one of MacAskill, Mogensen, and Ord’s key justifications for their principle, keeping costs low to the giver.

A fourth benefit is that it would capture an important difference in purchasing power that MacAskill, Mogensen, Ord, and Singer omit, namely wealth. This is especially important given the decreasing marginal utility of money. This principle shows that the 10% income donation sacrifice for the secretary is a larger sacrifice than the same percentage donation of income for the surgeon. This is true both because of income and net wealth. Assessed solely in terms of income, the surgeon will still have gobs of money left to spend after donating 10%. Further, because the surgeon is likely to save and invest far more than the secretary, the marginal utility of money for the secretary and the surgeon will likely continue to diverge throughout their careers.

Because the principle accounts for net wealth, it captures part of historical and contemporary injustices that result in wealth inequalities. This is both true across countries and within them. For example, because of the average wealth difference between Whites and Blacks in the US is large, it would require Whites to donate more than Blacks, on average. This would also apply to those individuals in countries that became wealthy in part through colonial exploitation and theft, unfair trade practices, etc.

To recap so far, a principle of progressive giving better fits the two main reasons MacAskill, Mogensen, and Ord give in support of their principle, namely the ease of which a giver can donate and the good that would likely result. It does this by overcoming an overdemandingness objection, being more action guiding, setting a fairer and more adjustable giving floor, and accounting for wealth differences (and thereby some historical injustices).

MacAskill, Mogensen, and Ord might reply that their proposal has practical purchase in that even though it is imperfect in the ways I have addressed, pushing tithing is an easy message to remember, measure, and implement. One way to think about this is the difference between ideal and non-ideal theory. Therefore it might end up doing more good than a Singerian suggestion of a progressive giving model based on income (Singer 2009, chap. 10). This is an empirical question, one to which we have no answer (of which I am aware). It is worth investigating. However, given the advantages of the principle progressive giving, especially the vast amounts of wealth being left on the proverbial table, plus the duty for at least those with sufficient privilege to be moderately well informed (Vanderheiden 2016), without further evidence to the contrary, I find this objection unpersuasive. There is also a practical aspect to this proposal. Each billionaire who gives $1b to effective organizations is the equivalent of 250,000 secretaries (earning $40,000) donating 10% of their after-tax income. Because of how easy it is for billionaires to give, and because over 200 have already taken a giving pledge (The Giving Pledge n.d..), it may be strategically preferable for effective altruists to focus more on persuading these economic elites to give more and to redirect their giving to the most effective organizations. Some Effective Altruist aligned organizations such as Founders Pledge and Effective Giving already focus on (ultra) high net worth individuals.

Conclusion

MacAskill, Mogensen, and Ord are right that giving does not have to be demanding, and that most rich people should donate more than they do to some of the most effective causes. But a principle of very weak sacrifice is likely better operationalized through a principle of progressive giving rather than a lower bar of tithing for most of the top 50% of income earners. Such a progressive giving principle should be based on a broader means of purchasing power than income alone, such as wealth, and a broader array of costs, including risks to bad outcomes and historical injustices.

Let me conclude with a potential exception for obligations to donate at a specific time. On either MacAskill, Mogensen, and Ord’s or my proposal, perhaps there should be some exceptions to donate today (or this year) if the good one could do in the future with the funds one could donate today will likely outweigh the good by donating done today (or this year) (MacAskill 2019; Moller 2006; Valentini 2011). If one has good reason to believe that expected investment returns would allow one to do more good in the future than giving to the most effective organization this year, this is an important reason to allow or require postponing donating. If one thinks that there are some instances where it is better to invest rather than donate today, considerations of net wealth become even more important.

Acknowledgments

Thanks to the anonymous reviewers, Lydie Cabane, Wouter Kalf, Honorata Mazepus, James Pattison, Andrei Poama, Ajume Wingo, Scott Wisor, the participants at the Leiden University Center for Political Philosophy, and the Netherlands Institute for Government 2019 Conference for helpful feedback on earlier versions of this paper and to Gordon Bearn for introducing me to work of Peter Singer many years ago.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

¹ Thanks to an anonymous reviewer for this helpful suggestion.