In a recent article in this journal, Duijf claims to have proved that team reasoning can be viewed as a payoff transformation. His formalization mimics team reasoning but ignores its essential agency switch. The possibility of such a payoff transformation was never in doubt, does not imply that team reasoning can be viewed as a payoff transformation, and makes no sense in a game in which payoffs represent players’ utilities. A theorem is proved here that a simpler and more intuitive payoff transformation can mimic any theory that predicts what strategies players will choose in a well-defined game.

This paper argues for two propositions. (I) Large asymmetries of power, status and influence exist between economists. These asymmetries constitute a hierarchy that is steeper than it could be and steeper than hierarchies in other disciplines. (II) This situation has potentially significant epistemic consequences. I collect data on the social organization of economics to show (I). I then argue that the hierarchy in economics heightens conservative selection biases, restricts criticism between economists and disincentivizes the development of novel research. These factors together constrain economics’ capacity to develop new beliefs and reduce the likelihood that its outputs will be true.

We present an abstract model of rationality that focuses on structural properties of attitudes. Rationality requires coherence between your attitudes, such as your beliefs, values and intentions. We define three ‘logical’ conditions on attitudes: consistency, completeness and closedness. They parallel the familiar logical conditions on beliefs, but contrast with standard rationality conditions such as preference transitivity. We establish a formal correspondence between our logical conditions and standard rationality conditions. Addressing John Broome’s programme ‘rationality through reasoning’, we formally characterize how you can (not) become more logical by reasoning. Our analysis connects rationality with logic, and enables logical talk about multi-attitude psychology.

I examine some behavioural and heuristic models of individual decision-making and argue that the diverse psychological mechanisms these models posit are too demanding to be implemented, either consciously or unconsciously, by actual decision makers. Accordingly, and contrary to what their advocates typically claim, behavioural and heuristic models are best understood as ‘as-if’ models. I then sketch a version of scientific antirealism that justifies the practice of as-if modelling in decision theory but goes beyond traditional instrumentalism. Finally, I relate my account of decision models to the recent controversy about mentalism versus behaviourism, reject both positions, and offer an alternative view.

Multiple selves is a conventional assumption in behavioural welfare economics for modelling intrapersonal well-being. Yet an important question is which self has normative authority over others. In this paper, we advance an argument for what we call the ‘ontological approach’ to personal identity in behavioural welfare economics. According to this approach, ethical questions – such as which preference should be granted normative authority over another – can be informed by the ontological criterion of personal persistence, which aims at determining what it takes for an individual to persist from one time to another.

This article refines a foundational tenet of rational choice theory known as the principle of description invariance. Attempts to apply this principle to human agents with imperfect knowledge have paid insufficient attention to two aspects: first, agents’ epistemic situations, i.e. whether and when they recognize alternative descriptions of an object to be equivalent; and second, the individuation of objects of description, i.e. whether and when objects count as the same or different. An important consequence is that many apparent ‘framing effects’ may not violate the principle of description invariance, and the subjects of these effects may not be irrational.

According to the Welfare Diffusion Objection, we should reject Prioritarianism because it implies the ‘desirability of welfare diffusion’: the claim that it can be better for there to be less total wellbeing spread thinly between a larger total number of people, rather than for there to be more total wellbeing, spread more generously between a smaller total number of people. I argue that while Prioritarianism does not directly imply the desirability of welfare diffusion, Prioritarians are nevertheless implicitly committed to certain principles for comparing different-number populations which, together with the Prioritarian same-person axiology, imply the desirability of welfare diffusion.

This article explains how social norms can help to distinguish and understand a range of different kinds of social inequality and social hierarchy. My aim is to show how the literature on social norms can provide crucial resources to relational egalitarianism, which has made social equality and inequality into a central topic of contemporary normative political theorizing. The hope is that a more discriminating and detailed picture of different kinds of social inequality will help relational egalitarians move beyond a discussion of the justice or injustice of social equality as a single general category.

Soda taxes are controversial. While proponents point to their potential health benefits and the public projects that could be funded with their revenue, critics argue that they are paternalistic and regressive. In this paper, we explore the prospects for designing a just soda tax, one that appropriately balances the often-competing ethical considerations of promoting social welfare, respecting people’s autonomy and ensuring distributive fairness. We argue that policymakers have several paths forward for designing a just soda tax, but that the considerations relevant to ethical policy design are more complicated than is sometimes acknowledged.

Normative welfare economics commonly assumes that individuals’ preferences can be reliably inferred from their choices and relies on preference satisfaction as the normative standard for welfare. In recent years, several authors have criticized welfare economists’ reliance on preference satisfaction as the normative standard for welfare and have advocated grounding normative welfare economics on opportunities rather than preferences. In this paper, I argue that although preference-based approaches to normative welfare economics face significant conceptual and practical challenges, opportunity-based approaches fail to provide a more reliable and informative foundation for normative welfare economics than preference-based approaches. I then identify and rebut various influential calls to ground normative welfare economics on opportunities rather than preferences to support my qualified defence of preference-based approaches.

Individuals often deem market transactions in sex, human organs and surrogacy, among others, repugnant. Repugnance norms can be explained by appealing to social-status concerns. We study an exchange economy in which agents abhor consumption dominance: one’s social status is compromised if one consumes less of every good than someone else does. Dominance may be forestalled by partitioning goods into submarkets and then invoking the repugnance norms that proscribe trade across these submarkets. Dominance may also be forestalled if individuals strategically ‘overconsume’ some goods, interpreted as emergent status goods. When equilibria are multiple, there is scope for welfare-enhancing policies that coordinate on status goods.

We propose a methodology for normative evaluation when preferences are context-dependent. We offer a precise definition of context-dependence and formulate a normative criterion of self-determination, according to which one situation is better than another if individuals are aware of more potential contexts of a choice problem. We provide two interpretations of our normative approach: an extension of Sugden’s opportunity criterion and an application of Sen’s positional views in his theory of justice. Our proposition is consistent with Muldoon’s and Gaus’ approaches of public reason in social contract theory, which account for the diversity of perspectives in non-ideal worlds.

David Lewis is widely regarded as the philosopher who introduced the concept of common knowledge. His account of common knowledge differs greatly from most later accounts in philosophy and economy, with the central notion of his theory being ‘having reason to believe’ rather than ‘knowledge’. Unfortunately, Lewis’s account is rather informal, and the argument has a few gaps. This paper assesses two major attempts to formalise Lewis’s account and argues that these formalisations are missing a crucial aspect of this account. Therefore, a new reconstruction is proposed, which explicitly discusses ‘reasons’ and uses a logic inspired by justification logic.

Behavioural techniques or ‘nudges’ can be used for various purposes. In this paper, we shift the focus from government nudges to nudges used by for-profit market agents. We argue that potential worries about nudges circumventing the deliberative capacities or diminishing the control of targeted agents are greater when it comes to market nudges, given that these (1) are not constrained by the principles that regulate government nudges (mildness, sensitivity to people’s interests and public justifiability) and (2) are often ‘stacked’ – they come in great numbers that overwhelm agents. In addition, we respond to possible objections and derive several policy suggestions.

It has been argued that Prioritarianism violates Risky Non-Antiegalitarianism, a condition stating roughly that an alternative is socially better than another if it both makes everyone better off in expectation and leads to more equality. I show that Risky Non-Antiegalitarianism is in fact compatible with Prioritarianism as ordinarily defined, but that it violates some other conditions that may be attractive to prioritarians. While I argue that the latter conditions are not core principles of Prioritarianism, the choice between these conditions and Risky Non-Antiegalitarianism nonetheless constitutes an important intramural debate for prioritarians.

The philosophical debate concerning political exchange has largely been confined to debating the desirability of vote trading; where individuals can sell their votes or buy votes from others. However, I show that the vote credit systems prevalent in public choice theory entirely avoid the common objections to political exchange that afflict vote trading proposals. Namely, vote credit systems avoid equality concerns and inalienability concerns. I offer an alternative critique to formal mechanisms that encourage political exchange by drawing on the role that impartiality and impartial moral judgements play in democratic and electoral institutions.

The valence of a life – that is, whether it is good, bad or neutral – is an important consideration in population ethics. This paper examines various definitions of valence. The main focus is ‘temporal’ definitions, which define valence in terms of the ‘shape’ of a life’s value over time. The paper argues that temporal definitions are viable only with a restricted domain, and therefore are incompatible with certain substantive theories of well-being. It also briefly considers some popular non-temporal definitions, and raises some problems for these.

In this paper we explore the absentminded driver problem using two different scenarios. In the first scenario we assume that the driver is capable of reasoning about his degree of absentmindedness before he hits the highway. This leads to a Savage-style model where the states are mutually exclusive and the act-state independence is in place. In the second we employ centred possibilities, by modelling the states (i.e. the events about which the driver is uncertain) as the possible final destinations indexed by a time period. The optimal probability we find for continuing at an exit is different from almost all papers in the literature. In this scenario, act-state independence is still violated, but states are mutually exclusive and the driver arrives at his optimal choice probability via Bayesian updating. We show that our solution is the only one guaranteeing immunity from sure loss via a Dutch strategy, and that – despite initial appearances – it is time consistent. This raises important implications for the rationality of commitment in such scenarios.

In Preference, Value, Choice, and Welfare, I argued, among other things, that preferences in economics are and ought to be total subjective comparative evaluations, that the theory of rational choice is a reformulation of everyday folk-psychological explanations and predictions of behaviour, and that revealed preference theory is completely untenable. All three of these theses have been challenged in essays by Erik Angner (2018), Francesco Guala (2019) and Johanna Thoma (2021a, 2021b). This essay responds to these criticisms and defends these three theses.

Endörfer has recently argued that proponents of the harm principle are wrong to exempt market harms as potential justifications for state interference. I argue that – contrary to suggestions in Endörfer’s article – John Stuart Mill did not exempt market harms from his harm principle. On Mill’s view, the state can (as a matter of principle) legitimately interfere with free markets to prevent market harms where they occur but, on the whole, it is better policy not to interfere. Mill’s general preference for free trade rests on utilitarian considerations and not on his harm principle, which does not exclude market harms.