This symposium contains a selection of the papers that were presented at a conference we organized on Rational Choice and Philosophy that was held at Vanderbilt University on 16 and 17 May 2014. The aim of the conference was to provide an inter-disciplinary forum for philosophical work that uses ideas and tools from rational choice theory, understood broadly to include decision theory, game theory and social choice theory.

We address the question, in decision theory, of how the value of risky options (gambles) should be assessed when they have no finite standard expected value, that is, where the sum of the probability-weighted payoffs is infinite or not well defined. We endorse, combine and extend (1) the proposal of Easwaran (2008) to evaluate options on the basis of their weak expected value, and (2) the proposal of Colyvan (2008) to rank options on the basis of their relative expected value.

The paper seeks to defend Telic Egalitarianism (TE) by distinguishing two distinct categories into which typical objections to it fall. According to one category of objections (for example, levelling down) TE is groundless. That is, there is simply no good reason to think that inequality as such is bad. The other type of objections to TE focuses on its counterintuitive implications: it is forced to condemn inequalities between ourselves and long-dead Inca peasants, or between us and worse-off aliens from other planets. The paper shows that once we unpack these two types of objections to TE they become much less persuasive.

We introduce a ‘reason-based’ framework for explaining and predicting individual choices. The key idea is that a decision-maker focuses on some but not all properties of the options and chooses an option whose ‘motivationally salient’ properties he/she most prefers. Reason-based explanations can capture two kinds of context-dependent choice: (i) the motivationally salient properties may vary across choice contexts, and (ii) they may include ‘context-related’ properties, not just ‘intrinsic’ properties of the options. Our framework allows us to explain boundedly rational and sophisticated choice behaviour. Since properties can be recombined in new ways, it also offers resources for predicting choices in unobserved contexts.

In Rescuing Justice and Equality, G.A. Cohen argues that the incentive inequalities permitted by John Rawls's difference principle are unjust since people cannot justify them to their fellow citizens. I argue that citizens of a Rawlsian society can justify their acceptance of a wide range of incentive inequalities to their fellow citizens. They can do so because they possess the right to freedom of occupational choice, and are permitted – as a matter of justice – to exercise this right by making occupational decisions on the basis of a wide range of values and preferences.

This paper explores the contrast between mentalistic and behaviouristic interpretations of decision theory. The former regards credences and utilities as psychologically real, while the latter regards them as mere representations of an agent's preferences. Philosophers typically adopt the former interpretation, economists the latter. It is argued that the mentalistic interpretation is preferable if our aim is to use decision theory for descriptive purposes, but if our aim is normative then the behaviouristic interpretation cannot be dispensed with.

What value should we put on our chances of obtaining a good? This paper argues that, contrary to the widely accepted theory of von Neumann and Morgenstern, the value of a chance of some good G may be a non-linear function of the value of G. In particular, chances may have diminishing marginal utility, a property that is termed chance uncertainty aversion. The hypothesis that agents are averse to uncertainy about chances explains a pattern of preferences often observed in the Ellsberg paradox. While these preferences have typically been taken to refute Bayesian decision theory, it is shown that chance risk aversion is perfectly compatible with it.

Should people who perform equal work receive equal pay? Most would say ‘yes’, at least insofar as this question is understood to be asking whether employers should be permitted to discriminate against employees on the basis of race or sex. But suppose the employees belong to all of the same traditionally protected groups. Is (what I call) nondiscriminatory unequal pay for equal work wrong? Drawing an analogy with price discrimination, I argue that it is not intrinsically wrong, but it can be deceptive, in which case it is wrong.

G.A. Cohen has criticized the capability approach for focusing on individuals’ freedom – their capability to control their lives – and ignoring benefits achieved passively. He argues that this view of well-being is excessively ‘athletic’. However, if the capability approach is employed to guide egalitarian public policy, capabilities are the appropriate goal of just distributive policies, not just components of individual well-being. When understood as a policy-guide, I argue that the capability approach's focus on ‘athletic’ individual freedom and control is justified: in the public domain, it is important not just that individuals receive benefits, but that they participate in their achievement.

Proponents of behavioural policies seek to justify them as ‘evidence-based’. Yet they typically fail to show through which mechanisms these policies operate. This paper shows – at the hand of examples from economics and psychology – that without sufficient mechanistic evidence, one often cannot determine whether a given policy in its target environment will be effective, robust, persistent or welfare-improving. Because these properties are important for justification, policies that lack sufficient support from mechanistic evidence should not be called ‘evidence-based’.

Behaviourism is the view that preferences, beliefs and other mental states in social-scientific theories are nothing but constructs re-describing people’s behaviour. Mentalism is the view that they capture real phenomena, on a par with the unobservables in science, such as electrons and electromagnetic fields. While behaviourism has gone out of fashion in psychology, it remains influential in economics, especially in ‘revealed preference’ theory. We defend mentalism in economics, construed as a positive science, and show that it fits best scientific practice. We distinguish mentalism from, and reject, the radical neuroeconomic view that behaviour should be explained in terms of brain processes, as distinct from mental states.

What is the value of a life? How should we regard death? This paper uses the methods of economics to defend some of the views of Epicurus against the utilitarian approach that welfare economics takes for granted.

Preference-aggregation problems arise in various contexts. One such context, little explored by social choice theorists, is metaethical. ‘Ideal-advisor’ accounts, which have played a major role in metaethics, propose that moral facts are constituted by the idealized preferences of a community of advisors. Such accounts give rise to a preference-aggregation problem: namely, aggregating the advisors’ moral preferences. Do we have reason to believe that the advisors, albeit idealized, can still diverge in their rankings of a given set of alternatives? If so, what are the moral facts (in particular, the comparative moral goodness of the alternatives) when the advisors do diverge? These questions are investigated here using the tools of Arrovian social choice theory.

I argue that a liberal commitment to value neutrality is best honoured by maintaining a pure cardinality component in our rankings of opportunity sets. Two challenges to this claim are considered. The first holds that cardinality rankings are unnecessary for neutrality, since what matters from this perspective is the variety (and not the mere size) of opportunity sets. The second holds that pure cardinality metrics are insufficient for neutrality, because opportunities cannot be individuated into countable entities without presupposing some relevantly partisan evaluative perspective. In each case, a clear understanding of the liberal basis for valuing liberty yields a satisfying response.

According to some accounts of exploitation, most notably Ruth Sample’s (2003) degradation-based account and Robert Goodin’s (1987) vulnerability-based account, exploitation occurs when an advantaged party fails to constrain their advantage in light of another’s disadvantage, regardless of the cause of this disadvantage. Because the duty of constraint in these accounts does not depend on the cause of the disadvantage, the advantaged’s duty of constraint is what I call a ‘come-what-may’ duty. I show that come-what-may duties create moral hazards that can themselves be exploited by the disadvantaged parties. In such cases these accounts of exploitation are either self-frustrating or over-demanding.

The most basic question one can ask of a model is ‘What is the effect on variable y2 of variable y1?’ Causation is ‘implementation neutral’ when all interventions on external variables that lead to a given change in y1 have the same effect on y2, so that the effect of y1 on y2 is defined unambiguously. Familiar ideas of causal analysis do not apply when causation is implementation neutral. For example, a cause variable cannot be linked to an effect variable by both a direct path and a distinct indirect path. Discussion of empirical aspects of implementation neutrality leads to further unexpected results, such as that if one variable causes another the coefficient representing that causal link is always identified.

Juries, committees and experts panels commonly appraise things of one kind or another on the basis of grades awarded by several people. When everybody's grading thresholds are known to be the same, the results sometimes can be counted on to reflect the graders’ opinion. Otherwise, they often cannot. Under certain conditions, Arrow's ‘impossibility’ theorem entails that judgements reached by aggregating grades do not reliably track any collective sense of better and worse at all. These claims are made by adapting the Arrow–Sen framework for social choice to study grading in groups.

The Pareto principle states that if the members of society express the same preference judgement between two options, this judgement is compelling for society. A building block of normative economics and social choice theory, and often borrowed by contemporary political philosophy, the principle has rarely been subjected to philosophical criticism. The paper objects to it on the ground that it applies indifferently to those cases in which the individuals agree both on their expressed preferences and on their reasons for entertaining them, and those cases in which they agree on their expressed preferences while differing on their reasons. The latter are cases of ‘spurious unanimity’, and it is normatively inappropriate, or so the paper argues, to defend unanimity preservation at the social level for such cases: thus the Pareto principle is formulated much too broadly. The objection seems especially powerful when the principle is applied in an ex ante context of uncertainty, in which individuals can disagree on both their probabilities and utilities, and nonetheless agree on their preferences over prospects.