Vaccines famously possess positive externalities that make them susceptible to the collective action dilemma: when I get vaccinated, I protect not only myself, but also those who I might otherwise have infected. Thus, some people will have an incentive to free ride on the immunity of others. In a population of rational agents, the critical level of vaccination uptake required for herd immunity will therefore be difficult to attain in the long run, which poses difficulties for disease eradication. In this doctoral dissertation, I explore different implications of the collective action dilemma of vaccination, and different ways of ameliorating it. First: given that coercion or force could solve the dilemma, and democracies may be less likely to engage in policies that violate the physical integrity of citizens, democracies may also be at a disadvantage compared to non-democracies when securing herd immunity. In essay I, I show that this is, empirically, indeed the case. Barring the use of extensive coercion therefore necessitates other solutions. In essay II, I highlight the exception to individual rationality found in other-regarding motivations such as altruism. Our moral psychology has likely evolved to take other's welfare into account, but the extent of our prosocial motivations vary: a wider form of altruism that encompasses not just family or friends, but strangers, is likely to give way to a more narrow form when humans pair-bond and have children. This dynamic is shown to apply to the sentiments underlying vaccination behavior as well: appeals to the welfare of society of getting vaccinated have positive effects on vaccination propensity, but this effect disappears in people with families and children. On this demographic, appeals to the welfare of close loved ones instead appears to have large effects. In essay III, I investigate whether the prosocial motivations underlying vaccination behavior are liable to be affected by motivation crowding - that is, whether they are crowded out when introducing economic incentives to get vaccinated. I find that on average, economic incentives do not have adverse effects, but for a small minority of highly prosocially motivated people, they might.

Two contrasting forms of advice for decision-makers are to either follow one’s heart (emotions) or one’s head (reason). This is a false dichotomy – but how should decision-makers combine heart and head? Decisions can be fruitfully analysed as a set of components: a decision-problem embedded within an on-going situation, with values-at-stake, possible options-with-consequences, choice, action and review. Structured decision-making models (head theories) approach this multifaceted nature of decisions by a divide-and-conquer strategy with thinking tasks provided to help decision-makers clarify the decision-problem, identify important values-at-stake, find credible options, choose the most credible option, act effectively and fairly review the outcomes of the choice. Emotions are complex and can also fruitfully be analysed as a set of components: an appraisal of a situation’s implication for the actor’s goals and values, bodily and cognitive changes, phenomenological experience and desires. Emotions can both help and hinder decision making, so wise decision-makers should neither ignore nor rely upon emotions, but instead treat emotions as fallible resources. The complex nature of emotions implies that different emotion-enabled tasks might assist decision-makers for different components of the decision. On the basis of this analysis an emotion-enabled, structured, decision-making procedure was developed and investigated by taking ten participants with decision dilemmas through the procedure. This investigation, based on repeated use of the Hermeneutic Single-Case Efficacy Design, provided some initial support for the effectiveness of the model: participants found the procedure generally helpful (p < 0.005), had increased confidence in their final choice (p < 0.005), which at follow-up they were satisfied with (p < 0.005). The use of emotions as fallible resources was also investigated through tracing emotion-enabled changes in participants’ decision making. Suggestions for further development and investigation of integrating emotions into structured approaches are offered.

We investigate principles of rationality based on symmetry in Polyadic Pure Inductive Logic. The aim of Pure Inductive Logic (PIL) is to determine how to assign probabilities to sentences of a language being true in some structure on the basis of rational considerations. This thesis centres on principles arising from instances of symmetry for sentences of first-order polyadic languages. We begin with the recently introduced Permutation Invariance Principle (PIP), and find that it is determined by a finite number of permutations on a finite set of formulae. We test the consistency of PIP with established principles of the subject and show, in particular, that it is consistent with Super Regularity. We then investigate the relationship between PIP and the two main polyadic principles thus far, Spectrum Exchangeability and Language Invariance, and discover there are close connections. In addition, we define the key notion of polyadic atoms as the building blocks of polyadic languages. We explore polyadic generalisations of the unary principle of Atom Exchangeability and prove that PIP is a natural extension of Atom Exchangeability to polyadic languages. In the second half of the thesis we investigate polyadic approaches to the unary version of Constant Exchangeability as invariance under signatures. We first provide a theory built on polyadic atoms (for binary and then general languages). We introduce the notion of a signature for non-unary languages, and principles of invariance under signatures, independence, and instantial relevance for this context, as well as a binary representation theorem. We then develop a second approach to these concepts using elements as alternative building blocks for polyadic languages. Finally, we introduce the concepts of homomorphisms and degenerate probability functions in Pure Inductive Logic. We examine which of the established principles of PIL are preserved by these notions, and present a method for reducing probability functions on general polyadic languages to functions on binary languages.

In this thesis, I explore a number of epistemological issues concerning the relations between knowledge, belief and practical matters. In particular, I defend a view, which I call credal pragmatism. This view is compatible with moderate invariantism, a view that takes knowledge to depend exclusively on truth-relevant factors and to require an invariant epistemic standard of knowledge that can be quite easily met. The thesis includes a negative and a positive part. In the negative part (Ch. 1-4) I do two things: i) I critically examine some moderate invariantist accounts of the intuitive influence of practical factors on knowledge ascriptions, and ii) I provide a criticism of the idea that knowledge is the norm of practical reasoning. In Chapter 1, I provide a general overview of the issues that constitute the background for the views and arguments defended in my thesis. In particular, I provide a thorough discussion of two aspects of the relation between knowledge and practical matters: one is constituted by the practical factors' effects on knowledge ascriptions; the other is the intuitive normative role of knowledge in the regulation and assessments of action and practical reasoning. In Chapter 2, I consider and criticize Timothy Williamson's account according to which an alleged failure to acknowledge the distinction between knowing and knowing that one knows generates the intuition that knowledge ascriptions are sensitive to practical factors. In Chapter 3, I argue against the idea that practical reasoning is governed by a knowledge norm. The argument generalizes to other candidate epistemic norms of practical reasoning. In Chapter 4, I criticise a number of accounts which explain effects of practical factors on knowledge ascriptions in terms of the influence of practical factors on belief. These include the accounts of Brain Weatherson, Dorit Ganson, Kent Bach and Jennifer Nagel. In the positive part of the thesis (Ch. 5-6), I develop and argue for credal pragmatism, an original account of the nature and interaction of different doxastic attitudes and the role of practical factors in their rational regulation. On this view, given a certain fixed amount of evidence, the degree of credence of an adaptively rational agent varies in different circumstances depending on practical factors, while the threshold on the degree of credence necessary for outright belief remains fixed across contexts. This account distinguishes between two kinds of outright belief: occurrent belief, which depends on the actual degree of credence, and dispositional belief, which depends on the degree of credence in normal circumstances. In Chapter 5, I present the view and I show how credal pragmatism can explain the practical factors' effects on knowledge ascriptions. In Chapter 6, I develop a fallibilist account of several features about knowledge ascriptions including i) why in folk epistemological practices knowledge is often taken to be a necessary and sufficient epistemic condition for relying on a proposition in practical reasoning; ii) concessive knowledge attributions and related data; and iii) the infallibilist intuition that knowledge excludes error possibilities.

This thesis analyses theories of practical reason. In particular I compare desire theories of reasons with value theories of reasons. Desire theories of reasons, as I define them, claim that it is a necessary condition of A having a reason to ф that A’s reason depend on A’s antecedent desires. In contrast, I define value theories of reasons as those theories that claim that it is a necessary condition of A having a reason to ф that A’s ф-ing be valuable. In this thesis my main concern lies with those value theorists who accept the motivational requirement: the claim that if an agent is to have a reason to ф, then it must be possible for the agent to ф on the basis of this reason. In particular, I concentrate on those value theorists who claim that A has a reason to ф iff a) A’s ф-ing is valuable; b) it is possible for A to ф on the basis of this reason. I reject desire theories of reasons on the basis of several criticisms. I claim that our desires are normatively arbitrary, and that according to desire theories of reasons, some of our desires ought to be eradicated. I argue instead for a value theory of reasons that adopts a particular interpretation of the motivational requirement. I distinguish three different interpretations of the motivational requirement, each offering a connection between reasons and motivations that differs in strength. The first, strongest requirement claims that in order for A to have a normative reason to ф, it must be possible for A to ф on the basis of this reason given certain qualities that A possesses (where I take the sense of ‘possible’ relevant to these interpretations to be one that reflects an agent’s capacities). The second and weakest requirement claims that in order for A to have a normative reason to ф, it must be possible for A to ф on the basis of this reason if A possessed certain qualities. The last and moderate requirement claims that in order for A to have a normative reason to ф, it must be possible for A to ф on the basis of this reason if A possessed certain qualities and A either has these qualities, or it is possible for her to get herself into a state where she has them. I argue for a value theory of reasons that employs this last, moderate motivational requirement. I argue that a value theory that adopts the moderate motivational requirement is best, as it allows the theory to be practically useful; reasons on this account have a role in deterrence, encouragement and praise- and blame-worthiness. The theory also aligns with a plausible account of eligible candidates for reasons. While the employment of the moderate motivational requirement in a value theory of reasons likens the theory, in some respects, to a desire theory, it avoids the objections raised against desire theories of reasons. In this way, a value theory of reasons that employs the moderate motivational requirement combines the attractive features of a desire theory and a value theory. Specifically, it generates reasons that are both dependent on an individual’s qualities, and also aligned with an account of value. / Thesis (Ph.D.) - University of Adelaide, School of Humanities, 2008

<p>This essay presents empirical tests of one of the conclusions from Bryan Caplan's 2007 book <em>The Myth of the Rational Voter. </em>Caplan claims that voters suffer from systematic biases about economic policy that through elections affects economic policy negatively. I derive three hypotheses from Caplan's theory and test them on a cross-country panel of 19 countries covering the time 1973 to 2009. The hypotheses stipulate that increased turnout lead to lower economic freedom, lower levels of foreign aid and higher inflation. After controlling for country specific effects turnout does not seem to have the effect stipulated in the three hypotheses.</p>

This essay presents empirical tests of one of the conclusions from Bryan Caplan's 2007 book The Myth of the Rational Voter. Caplan claims that voters suffer from systematic biases about economic policy that through elections affects economic policy negatively. I derive three hypotheses from Caplan's theory and test them on a cross-country panel of 19 countries covering the time 1973 to 2009. The hypotheses stipulate that increased turnout lead to lower economic freedom, lower levels of foreign aid and higher inflation. After controlling for country specific effects turnout does not seem to have the effect stipulated in the three hypotheses.

In this paper, a view of non-compliance in practical healthcare is provided that identifies certain non-compliant behaviours as rational. This view of rational non-compliance is used to update a current form of doctor patient relationships with the aim of reducing non-compliance. In addition to reforming one standard doctor patient relationship model, the normative implications of understanding non-compliance as a rational form of human behaviour are described.

Since equity premium puzzle had long been a problem, many economists tried to give reasonable interpretations to the puzzle. I focus on the type of theories using bounded rationality as the answer to the problem. I am willing to find out that whether the puzzle still exists in recent decades. If it does exist, are the theories of bounded rationality still able to explain the puzzle? In the beginning, I introduce two theories referring to bounded rationality. Afterwards, I empirically analyze the data of the U.S., Japan and Euro-area by using a simpler model based on rationality. Interestingly, circumstances vary a lot from country to country. One theory may be suitable for one country but not for the others. Even so, the “suitable” theory fails to completely explain the whole tendency of variation during the observed period in the country. In the future, we still need to explore in depth of the puzzle.

Alasdair MacIntyre is one of the key philosophers in contemporary revival of virtue ethics, and often labeled as a representative of communitarianism in liberal-communitarian debate. The purpose of this thesis is to provide a narrative of the development of MacIntyre's philosophy, from his early Marxist thought to the later virtue ethics, and to examine the continuities and discrepancies between different stages of his philosophy. This thesis argues that the central theme of MacIntyre's philosophy is a diagnosis of the crisis of modernity and the ways through which we can overcome the predicament of alienation. In other words, MacIntyre's critique of capitalism and liberalist individualism shows the sophistication of his political thought and therefore cannot simply be described as "communitarian." To demonstrate MacIntyre's analysis of the crisis of modernity, this thesis focuses on four sets of binary concepts that constitute the foundations of his critiques, that is, "is-ought", "theory-practice", "individualism-holism", and "philosophy-history". The key to his theory of overcoming alienation, in this interpretation, is to understand the dialectic relations within each set of binary concepts respectively. This thesis illustrates how young MacIntyre tried to combine Marxism and Christian theology to answer these problematics, as well as how the later MacIntyre turned to Aristotle and Aquinas for theoretical inspirations. Aside from re-articulating the role of virtues in ethics, other MacIntyre's important theoretical innovations include transcending modern instrumental rationality by elevating the significance of teleological rationality and reconstructing the dynamic relations between rationality and traditions.