The effectiveness of heuristics has received contradicting interpretations in the behavioural sciences. We study the policy implications of two programmes that dispute the effectiveness of heuristics – the biases and heuristics and the fast and frugal heuristics programmes. While the first blames heuristics for most errors in judgement, the second posits heuristics as simple mental algorithms that work well in a range of environments. We argue that the fast and frugal programme is less paternalistic insofar as it models humans as effective decision-makers in a range of environments. However, in the rapidly changing environments of the 21st century, both are needed to inform evidence-based policies.

In this paper I argue that libertarianism neither prohibits exchanges in which consent is gained through deceit, nor does it entail that such exchanges are morally invalid. However, contra James Child’s (1994) similar claim, that it is incapable of delivering these verdicts, I argue that libertarians can claim that exchanges involving deceitfully obtained consent are morally invalid by appealing to an external theory of moral permissibility.

Team reasoning is thought to be descriptively and normatively superior to the classical individualistic theory of rational choice primarily because it can recommend coordination on Hi in the Hi-Lo game and cooperation in Prisoner's Dilemma-type situations. However, left unanswered is whether it is rational for individuals to become team members, leaving a gap between reasons for individuals and reasons for team members. In what follows, I take up Susan Hurley's attempt to show that it is rational for an individual to become a team member. I argue that her account fails to show that becoming a team member is necessary to gain the advantages of coordination in Hi-Lo games or cooperation in Prisoner's Dilemma-type situations, and that individuals will often fare better reasoning as individual agents than as members of a team. I argue further that there is a more general problem for team reasoning, specifically that the conditions needed to make it rational for a team member to employ team reasoning make becoming a team member unnecessary.

The Small Improvement Argument (SIA) is the leading argument for value incomparability. All vagueness-based accounts of the SIA have hitherto assumed the truth of supervaluationism, but supervaluationism has some well-known problems. This paper explores the implications of epistemicism, a leading rival theory. We argue that if epistemicism is true, then options are comparable in small improvement cases. Moreover, even if SIAs do not exploit vagueness, if epistemicism is true, then options cannot be on a par. The epistemicist account of the SIA has an advantage over leading existing rival accounts of the SIA because it accounts for higher-order hard cases.

Standard lessons from economics tell us that an externality creates inefficiency, and that this inefficiency can be removed by internalizing the externality. This papers considers how successfully these lessons can be extended to intergenerational externalities such as emissions of greenhouse gas. For intergenerational externalities, the standard lessons involve comparisons between states whose populations of people differ, either in their identities or their numbers. Common notions of efficiency break down in these comparisons. This paper supplies a new notion of efficiency that allows the lessons to survive, but at the cost of reducing their practical significance.

In this paper, we analyse the difference between two types of behavioural policies – nudges and boosts. We distinguish them on the basis of the mechanisms through which they are expected to operate and identify the contextual conditions that are necessary for each policy to be successful. Our framework helps judging which type of policy is more likely to bring about the intended behavioural outcome in a given situation.