Bele Wollesen

This paper evaluates the Condorcet Jury Theorem in the context of ambiguity. It explores the effects on the assumption of voter competence when voters face situations in which they can no longer ascribe a single probability. In contrast to voting in situations where voters are able to assign such probabilities, this paper demonstrates that voters may fail to vote competently under ambiguity, even if they are honest, practically rational, and epistemically competent. Thus, the conditions under which voter competence can be guaranteed become unclear once we adopt a less idealised framework of uncertainty. Specifically, conditions that ensure voter competence under risk do not necessarily guarantee voter competence under ambiguity. The second contribution is a more positive one. It outlines a fruitful research agenda aimed at identifying collective decision procedures that are better suited to less idealised uncertainty frameworks. In this regard, the paper shows how allowing abstention can have positive effects on the epistemic benefits of voting and extends the Condorcet Jury Theorem accordingly.

Social choice theory provides fundamental tools for many sciences. Moreover, its models are applied and implemented in a remarkable range of diverse contexts to guide collective decision procedures. Understanding these models of collective decision-making and their normative verdicts poses an important challenge to philosophers of science, epistemologists, political philosophers, and philosophers of technology. This thesis is a collection of four papers that question the assumptions in social choice theory models at the intersection of individual decision-making and the design of collective decision mechanisms. The chapters, in particular, target the normative verdicts of these models by drawing on perspectives from the philosophy of science, political philosophy, and psychology. The central claims defended in the thesis are twofold. Firstly, the core claim is that abstracting away from individual decision-making does not always lead to greater generality but often makes the verdicts of social choice models inapplicable to the intended target systems. This observation draws on the fact that most target systems of social choice models involve individuals. Individuals are significant both in how they interact within a collective decision mechanism and as the object of normative consideration. Particular assumptions about individual decision-making, although often absent in a given social choice theory model itself, are needed for the model’s normative verdict to transfer to many target systems. Secondly, many models developed by social choice theory not only require scrutiny of their descriptive assumptions but also need an explication of the normative commitments underpinning them. Normative assumptions in social choice theory typically take the form of axioms or desiderata that are prima facie difficult to reject. However, the values underlying the acceptance of a given axiom can vary greatly, which, in turn, can significantly affect whether the model’s normative verdict successfully transfers to the intended target system.