Is risk aversion irrational? Examining the “fallacy” of large numbers

A moderately risk averse person may turn down a 50/50 gamble that either results in her winning $200 or losing$100. Such behaviour seems rational if, for instance, the pain of losing $100 is felt more strongly than the joy of winning$200. The aim of this paper is to examine an influential argument that some have interpreted as showing that such moderate risk aversion is irrational. After presenting an axiomatic argument that I take to be the strongest case for the claim that moderate risk aversion is irrational, I show that it essentially depends on an assumption that those who think that risk aversion can be rational should be skeptical of. Hence, I conclude that risk aversion need not be irrational

Ambiguity Aversion behind the Veil of Ignorance

The veil of ignorance argument was used by John C. Harsanyi to defend Utilitarianism and by John Rawls to defend the absolute priority of the worst off. In a recent paper, Lara Buchak revives the veil of ignorance argument, and uses it to defend an intermediate position between Harsanyi's and Rawls' that she calls Relative Prioritarianism. None of these authors explore the implications of allowing that agent's behind the veil are averse to ambiguity. Allowing for aversion to ambiguity---which is both the most commonly observed and a seemingly reasonable attitude to ambiguity---however supports a version of Egalitarianism, whose logical form is quite different from the theories defended by the aforementioned authors. Moreover, it turns out that the veil of ignorance argument neither supports standard Utilitarianism nor Prioritarianism unless we assume that rational people are insensitive to ambiguity

Land Users – Land Watchers

GróLind is a collaborative project with the aim of monitoring Icelandic vegetation and soil resources. It was founded in 2017 by the Icelandic National Associations of Sheep Farmers, the Farmers Association of Iceland, Ministry of Industries and Innovation, and the Soil Conservation Service of Iceland. GróLind is a collaborative project and cooperation with stakeholders, such as the science community, landowners, and others, is a fundamental concept in the project. In this project, the state of vegetation and soils are evaluated. Currently, a citizen science project is being developed within GróLind, in which land-users will annually monitor, using a mobile app, the conditions of the land they utilize. The monitoring will be based up on permanent photo-points and simple ecological measurements. These data will be used together with more detailed measurements done by specialists, to assess the state and changes in Iceland\u27s vegetation and soil resources. Land users\u27 participation provides more extensive and accurate monitoring, both spatially and temporally. Cooperation between scientists and land users increases the flow of knowledge and trust between groups, ensuring that the knowledge gained in the project will be used for sustainable land management. Furthermore, the data will be used to develop research-based indicators for sustainable land-use that later can simplify the monitoring

How a pure risk of harm can itself be a harm: A reply to Rowe

Argues that given an appropriate understanding of objective probabilities, pure objective risk of harm can itself be a harm

The tragedy of the risk averse

Those who are risk averse with respect to money, and thus turn down some gambles with positive monetary expectations, are nevertheless often willing to accept bundles involving multiple such gambles. Therefore, it might seem that such people should become more willing to accept a risky but favourable gamble if they put it in context with the collection of gambles that they predict they will be faced with in the future. However, it turns out that when a risk averse person adopts the long-term perspective, she faces a decision-problem that can be analysed as a noncooperative game between different "time-slices" of herself, where it is in the interest of each time-slice (given its prediction about other slices) to turn down the gamble with which it is faced. Hence, even if a risk averse but rational person manages to take the long-term perspective, she will, in the absence of what Hardin called "mutual coercion", end up in a situation analogous to the "tragedy of the commons"

In defence of Pigou-Dalton for chances

I defend a weak version of the Pigou-Dalton principle for chances. The principle says that it is better to increase the survival chance of a person who is more likely to die rather than a person who is less likely to die, assuming that the two people do not differ in any other morally relevant respect. The principle justifies plausible moral judgements that standard ex post views, such as prioritarianism and rank-dependent egalitarianism, cannot accommodate. However, the principle can be justified by the same reasoning that has recently been used to defend the core axiom of ex post prioritarianism and egalitarianism, namely, Pigou-Dalton for well-being. The arguably biggest challenge for proponents of Pigou-Dalton for chances is that it violates State Dominance for social prospects. However, I argue that we have independent reason for rejecting State Dominance for social prospects, since it prevents a social planner from properly respecting people's preferences

Radical interpretation and decision theory

This paper takes issue with an influential interpretationist argument for physicalism about intentionality based on the possibility of radical interpretation. The interpretationist defends the physicalist thesis that the intentional truths supervene on the physical truths by arguing that it is possible for a radical interpreter, who knows all of the physical truths, to work out the intentional truths about what an arbitrary agent believes, desires, and means without recourse to any further empirical information. One of the most compelling arguments for the possibility of radical interpretation, associated most closely with David Lewis and Donald Davidson, gives a central role to decision theoretic representation theorems, which demonstrate that if an agent’s preferences satisfy certain constraints, it is possible to deduce probability and utility functions that represent her beliefs and desires. We argue that an interpretationist who wants to rely on existing representation theorems in defence of the possibility of radical interpretation faces a trilemma, each horn of which is incompatible with the possibility of radical interpretation

Climate Change and Decision Theory

Many people are worried about the harmful effects of climate change but nevertheless enjoy some activities that contribute to the emission of greenhouse gas (driving, flying, eating meat, etc.), the main cause of climate change. How should such people make choices between engaging in and refraining from enjoyable greenhouse-gas-emitting activities? In this chapter we look at the answer provided by decision theory. Some scholars think that the right answer is given by interactive decision theory, or game theory; and moreover think that since private climate decisions are instances of the prisoner’s dilemma, one rationally should engage in these activities provided that one enjoys them. Others think that the right answer is given by expected utility theory, the best-known version of individual decision theory under risk and uncertainty. In this chapter we review these different answers, with a special focus on the latter answer and the debate it has generated