Mark Budolfson

Animals, like humans, experience different levels of well-being depending on decisions made by others. As a result, the well-being of animals must be included in any full accounting of the well-being consequences of decisions. However, this is almost never done in large-scale policy and investment analyses, even though it is common to quantify the consequences for human welfare in these decision analyses. This is partly due to prejudice, but increasingly also because we do not currently have good methods for quantifying animal well-being consequences and putting them on the same scale as quantified human well-being consequences. We might call this ‘the problem of interspecies comparisons.’ This important barrier to including animal well-being in decision-making is the result of an insufficiently developed theory and practice of animal well-being and its relation to human well-being. This chapter explains the problem of interspecies comparisons, explains recent research that develops methods to overcome this problem.

The spectre of the repugnant conclusion and the search for a population axiology that avoids it has endured as a focus of population ethics. This is in part because the repugnant conclusion is often interpreted as a defining problem for totalism, while the implications of averagism and related views are taken to illustrate the theoretical cost of avoiding the repugnant conclusion. However, we show that this interpretation cannot be sustained unless one focuses only on a special case of the repugnant conclusion: namely, the subset of instances of the repugnant conclusion where there is no portion of the population unaffected by the choice between population outcomes (as in Derek Parfit’s original illustration). To avoid an inappropriate focus on only this proper subset of instances of the repugnant conclusion, we formulate a general characterization of the repugnant conclusion. We then prove formally that all leading welfarist axiologies imply this conclusion, including averagism and Ng’s Theory X0, including probabilistic and ‘very repugnant’ variants that involve the addition of negative lives. We then prove that the full range of axiologies considered by population ethics each imply an extended version of the repugnant conclusion, including axiologies that are incomplete, intransitive, rank-dependent, person-affecting, and/or pluralist. The upshot is that the repugnant conclusion does not ultimately tell against any approach to axiology, and the methodological requirement to avoid the repugnant conclusion should be dropped from population axiology.

When is it wrong to buy something? Is it wrong whenever the product was produced unethically? What if your purchase doesn’t make adifference to whether the unethical practice continues? What about purchasing and eating animal products specifically? And however answer all those questions, how should we engage with people who act wrongly as consumers? In this essay, Mark Budolfson provides some tools for thinking more clearly about these questions, arguing that we need to be careful to separate our assessment of how things are produced from our assessment of consumers.

It is often stated that optimal global climate policy requires global harmonization of marginal abatement costs – i.e., a single carbon price throughout the world. Chichilnisky and Heal (1994) have shown quite generally that this is only the case if distributional issues are ignored, or if lump-sum transfers are made between countries. Else, a policy in which different regions face different carbon prices may be superior to one with a single global carbon price from a welfare point of view. Still, most integrated assessment models (IAMs) assume away distributional issues and report a single optimal carbon price. We calculate utilitarian-optimal carbon prices under zero cross-regional lump-sum transfers in the multi-region IAM NICE. The result is optimal global climate policy with different regional carbon prices in which the poorest regions face initially low prices, while the richest regions face very high prices from the outset. This entails significant welfare gains over the standard single price optima commonly reported, which, as we argue briefly in conclusion, can be improved upon still by allowing international trading in the corresponding emissions allocations.

The health co-benefits of CO2 mitigation can provide a strong incentive for climate policy through reductions in air pollutant emissions that occur when targeting shared sources. However, reducing air pollutant emissions may also have an important co-harm, as the aerosols they form produce net cooling overall. Nevertheless, aerosol impacts have not been fully incorporated into cost-benefit modeling that estimates how much the world should optimally mitigate. Here we find that when both co-benefits and co-harms are taken fully into account, optimal climate policy results in immediate net benefits globally, overturning previous findings from cost-benefit models that omit these effects. The global health benefits from climate policy could reach trillions of dollars annually, but will importantly depend on the air quality policies that nations adopt independently of climate change. Depending on how society values better health, economically optimal levels of mitigation may be consistent with a target of 2 °C or lower.

Formal arguments have proven that avoiding the Repugnant Conclusion is impossible without rejecting one or more highly plausible population principles. To many, such proofs establish not only a deep challenge for axiology, but also pose an important practical problem of how policymaking can confidently proceed without resolving any of the central questions of population ethics. Here we offer deflationary responses: first to the practical challenge, and then to the more fundamental challenge for axiology. Regarding the practical challenge, we provide an overview of recent literature that explores the implications for public policy of the Repugnant Conclusion and related puzzles within population ethics, and shows that there is more commonality in the implications of different population axiologies than is generally recognized. The upshot is that uncertainty about population ethics presents no important problem for policymaking, and the importance of population ethics to policymaking has been overstated. We then turn to more fundamental issues about axiology, and describe a new series of formal proofs that undermine the idea that any plausible axiology could avoid the Repugnant Conclusion, including those that are assumed to avoid it in the literature. The philosophical upshot is that the Repugnant Conclusion cannot plausibly be avoided, and so it is a mistake to assume as a constraint on a plausible axiology that it must be avoided, as is assumed by most of the literature in population ethics, including by all of the fundamental impossibility theorems.

Integrated assessment models of climate and the economy provide estimates of the social cost of carbon and inform climate policy. We create a variant of the Regional Integrated model of Climate and the Economy (RICE)—a regionally disaggregated version of the Dynamic Integrated model of Climate and the Economy (DICE)—in which we introduce a more fine-grained representation of economic inequalities within the model’s regions. This allows us to model the common observation that climate change impacts are not evenly distributed within regions and that poorer people are more vulnerable than the rest of the population. Our results suggest that this is important to the social cost of carbon—as significant, potentially, for the optimal carbon price as the debate between Stern and Nordhaus on discounting.

Integrated assessment models (IAMs) of climate and the economy provide estimates of the social cost of carbon and inform climate policy. With the Nested Inequalities Climate Economy model (NICE) (Dennig et al. PNAS 112:15,827–15,832, 2015), which is based on Nordhaus’s Regional Integrated Model of Climate and the Economy (RICE), but also includes inequalities within regions, we investigate the comparative importance of several factors—namely, time preference, inequality aversion, intraregional inequalities in the distribution of both damage and mitigation cost and the damage function. We do so by computing optimal carbon price trajectories that arise from the wide variety of combinations that are possible given the prevailing range of disagreement over each factor. This provides answers to a number of questions, including Thomas Schelling’s conjecture that properly accounting for inequalities could lead the inequality aversion parameter to have an effect opposite to what is suggested by the Ramsey equation.

This chapter identifies and critically examines a standard form of argument for organic and vegan alternatives to industrial agriculture. This argument faces important objections to its empirical premises, to its presumption that there is a single food system that minimizes harm and is best for the environment, and to the presumption that the ethically best food system for us to promote is the one that would be best in ideal theory or the one that would be best from the perspective of our own society. Instead, determining which food system should be promoted arguably requires a complex global, empirical, and ethical integrated assessment that includes a proper accounting for values of global justice in nonideal theory. This proper accounting arguably recommends sustainable intensification of food systems (as it is called in the food-science literature), which is importantly distinct from contemporary systems as well as from organic, local, and/or vegan-centered alternatives.

Over the past few decades, we have improved our understanding of the health impacts of climate change.1 Although many public health researchers have contributed to this knowledge, relatively few are aware of how their work may relate to the social cost of carbon. The social cost of carbon is a core economic concept in climate policy and one that can—and should—benefit directly from research produced by the public health community. The concept’s importance was recently highlighted by this past year’s Nobel Prize in Economic Sciences, which was awarded to William Nordhaus in part for his pioneering work developing models to estimate the social cost of carbon. Below we describe this concept, explain how it is calculated, and provide some brief guidance on how health research can improve its estimation.

How much should the present generations sacrifice to reduce emissions today, in order to reduce the future harms of climate change? Within climate economics, debate on this question has been focused on so-called “ethical parameters” of social time preference and inequality aversion. We show that optimal climate policy similarly importantly depends on the future of the developing world. In particular, although global poverty is falling and the economic lives of the poor are improving worldwide, leading models of climate economics may be too optimistic about two central predictions: future population growth in poor countries, and future convergence in total factor productivity (TFP). We report results of small modifications to a standard model: under plausible scenarios for high future population growth (especially in sub-Saharan Africa) and for low future TFP convergence, we find that optimal near-term carbon taxes could be substantially larger.

In this chapter, Mark Budolfson and Dean Spears analyse the marginal effect of philanthropic donations. The core of their analysis is the observation that marginal good done per dollar donated is a product (in the mathematical sense) of several factors: change in good done per change in activity level of the charity in question, change in activity per change in the charity’s budget size, and change in budget size per change in the individual’s donation to the charity in question. They then discuss the “hidden zero problem” that some of the terms in the equation (in particular, the last term) might be “hidden zeros” that prevent donations from doing any good—or worse, imply that they do harm—even if the charity is at the top of effective altruism rankings based on the other factors.

Non-cognitivism might seem to offer a plausible account of evaluative judgments, at least on the assumption that there is a satisfactory solution to the Frege-Geach problem. However, Cian Dorr has argued that non-cognitivism remains implausible even assuming that the Frege-Geach problem can be solved, on the grounds that non-cognitivism still has to classify some paradigmatically rational inferences as irrational. Dorr's argument is ingenious and at first glance seems decisive. However, in this paper I will show that Dorr's argument equivocates between two different notions of evidence, and that once this equivocation is noted there is no reason to doubt that non-cognitivism is consistent with the rationality of such inferences, at least if it is assumed that the Frege-Geach problem can be solved. In particular, I will show that non-cognitivists can endorse the same explanation of the rationality of such inferences that cognitivists should endorse, and that there is thus no need for non-cognitivists to offer any sort of idiosyncratic account of the epistemology of such cases, in contrast to what other commentators on Dorr's argument have thought.

The standard interpretation of Aldo Leopold’s land ethic is that correct land management is whatever tends to preserve the integrity, stability, and beauty of the biotic community, of which we humans are merely a small part. From this interpretation, it is a short step to interpreting Leopold as a sort of deep ecologist or radical environmentalist. However, this interpretation is based on a small number of quotations from Leopold taken out of context. Once these quota­tions are put into context, and once the broader context of Leopold’s mature writings and his actions as a land manager are taken into account, it becomes clear that he is much closer to being an enlightened anthropocentrist than he is to being anything like a radical environmentalist. When properly understood, Leopold’s land ethic recognizes that fundamental human interests must be treated with the highest possible respect, and it emphasizes the incredible challenge and need for modesty in identifying the correct tradeoffs between lesser human interests and the interests of the broader biotic community.

Collective action problems lie behind many core issues in ethics and social philosophy—for example, whether an individual is required to vote, whether it is wrong to consume products that are produced in morally objectionable ways, and many others. In these cases, it matters greatly what we together do, but yet a single individual’s ‘non-cooperative’ choice seems to make no difference to the outcome and also seems to involve no violation of anyone’s rights. Here it is argued that—contrary to influential arguments by Peter Singer, Alastair Norcross, Shelly Kagan, Derek Parfit, and Allan Gibbard—an appeal to the expected consequences of acts cannot deliver plausible verdicts on many of these cases, because individuals often have a probability of making a difference that is sufficiently small to ensure that ‘non-cooperation’ is the option with the greatest expected value, even when consequentialists themselves agree that ‘cooperation’ is required. In addition, an influential argument by Singer, Norcross, and Kagan is shown to be unsound for the claim that in the collective action situations at issue, the expected effect of one individual’s action equals the average effect of everyone’s similar actions. These results have general implications for normative theory, because they undermine the sort of consequentialist explanation of collective action cases that is initially attractive from many theoretical points of view, consequentialist and otherwise.

The handbook is a partial survey of multiple areas of food ethics: conventional agriculture and alternatives to it; animals; consumption ethics; food justice; food workers; food politics and policy; gender, body image, and healthy eating; and, food, culture and identity. Food ethics, as an academic pursuit, is vast, incorporating work from philosophy as well as anthropology, economics, environmental sciences and other natural sciences, geography, law, and sociology. This Handbook provides a sample of recent philosophical work in food ethics. This philosophical work addresses ethical issues with agricultural production, the structure of the global food system, the ethics of personal food consumption, the ethics of food policy, and cultural understandings of food and eating, among other issues. The work in this Handbook draws on multiple literatures within philosophy, including practical ethics, normative ethics, and political philosophy, as well as drawing on non-philosophical work. Part I considers ethical issues concerning the industrial model of farming that dominates in developed countries, looking most closely at industrial crop farming and its environmental effects. Part II concerns the ethics of animal agriculture. Part III concerns the ethics of consumption: is it morally permissible to consume various products? Part IV concerns justice—including racial, social, and economic justice—in the food system. Part V discusses some ethical and legal issues with specific kinds of food policies, including healthy eating policies, food labeling, and agricultural guest worker programs. Part VI includes four essays taking a critical eye to our public discourse about, and personal experiences of, dieting, healthy eating, and obesity prevention. Lastly, the essays in Part VII concern the personal, social, and moral significance of food.

We analyze the role of ethical values in the determination of the social cost of carbon, arguing that the familiar debate about discounting is too narrow. Other ethical issues are equally important to computing the social cost of carbon, and we highlight inequality, risk, and population ethics. Although the usual approach, in the economics of cost-benefit analysis for climate policy, is confined to a utilitarian axiology, the methodology of the social cost of carbon is rather flexible and can be expanded to a broader set of social-welfare approaches. [Open access]