•  67
    Are objective chances compatible with determinism?
    Philosophy Compass 12 (8). 2017.
    We review the question of whether objective chances are compatible with determinism. We first outline what we mean by chance and what we mean by determinism. We then look at the alleged incompatibility between those concepts. Finally, we look at some ways that one might attempt to overcome the incompatibility.
  •  188
    Rational credence should be coherent in the sense that your attitudes should not leave you open to a sure loss. Rational credence should be such that you can learn when confronted with relevant evidence. Rational credence should not be sensitive to irrelevant differences in the presentation of the epistemic situation. We explore the extent to which orthodox probabilistic approaches to rational credence can satisfy these three desiderata and find them wanting. We demonstrate that an imprecise pro…Read more
  •  198
    This paper presents a decision problem called the holiday puzzle. The decision problem is one that involves incommensurable goods and sequences of choices. This puzzle points to a tension between three prima facie plausible, but jointly incompatible claims. I present a way out of the trilemma which demonstrates that it is possible for agents to have incomplete preferences and to be dynamically rational. The solution also suggests that the relationship between preference and rational permission …Read more
  •  19
    Learning by Ignoring the Most Wrong
    Kriterion – Journal of Philosophy 36 (1): 9-31. 2022.
    Imprecise probabilities are an increasingly popular way of reasoning about rational credence. However they are subject to an apparent failure to display convincing inductive learning. This paper demonstrates that a small modification to the update rule for IP allows us to overcome this problem, albeit at the cost of satisfying only a weaker concept of coherence.
  •  458
    On the appropriate and inappropriate uses of probability distributions in climate projections and some alternatives
    with Joel Katzav, Erica L. Thompson, James Risbey, David A. Stainforth, and Mathias Frisch
    Climatic Change 169 (15). 2021.
    When do probability distribution functions (PDFs) about future climate misrepresent uncertainty? How can we recognise when such misrepresentation occurs and thus avoid it in reasoning about or communicating our uncertainty? And when we should not use a PDF, what should we do instead? In this paper we address these three questions. We start by providing a classification of types of uncertainty and using this classification to illustrate when PDFs misrepresent our uncertainty in a way that may adv…Read more
  •  9
    Scientific uncertainty and decision making
    Dissertation, London School of Economics. 2012.
    It is important to have an adequate model of uncertainty, since decisions must be made before the uncertainty can be resolved. For instance, flood defenses must be designed before we know the future distribution of flood events. It is standardly assumed that probability theory offers the best model of uncertain information. I think there are reasons to be sceptical of this claim. I criticise some arguments for the claim that probability theory is the only adequate model of uncertainty. In particula…Read more
  •  4
    Probabilistic forecasting: why model imperfection is a poison pill
    with Roman Frigg, Reason L. Machete, and Leonard A. Smith
    In Hanne Andersen, Dennis Dieks, Wenceslao Gonzalez, Thomas Ubel & Gregory Wheeler (eds.), New Challenges to Philosophy of Science, . pp. 479-492. 2013.
    This volume is a serious attempt to open up the subject of European philosophy of science to real thought, and provide the structural basis for the interdisciplinary development of its specialist fields, but also to provoke reflection on the idea of ‘European philosophy of science’. This efforts should foster a contemporaneous reflection on what might be meant by philosophy of science in Europe and European philosophy of science, and how in fact awareness of it could assist philosophers interpre…Read more
  •  12
    Making sense of non-factual disagreement in science
    Studies in History and Philosophy of Science Part A 83 36-43. 2020.
  •  11
    This chapter explores the topic of imprecise probabilities as it relates to model validation. IP is a family of formal methods that aim to provide a better representationRepresentation of severe uncertainty than is possible with standard probabilistic methods. Among the methods discussed here are using sets of probabilities to represent uncertainty, and using functions that do not satisfy the additvity property. We discuss the basics of IP, some examples of IP in computer simulation contexts, po…Read more
  •  88
    Imprecise Probabilities
    Stanford Encyclopedia of Philosophy. 2019.
  •  6
    Laplace's demon and climate change
    with Roman Frigg, Hailiang Du, and Leonard A. Smith
  •  44
    Models on the move: Migration and imperialism
    Studies in History and Philosophy of Science Part A 77 81-92. 2019.
    We introduce ‘model migration’ as a species of cross-disciplinary knowledge transfer whereby the representational function of a model is radically changed to allow application to a new disciplinary context. Controversies and confusions that often derive from this phenomenon will be illustrated in the context of econophysics and phylogeographic linguistics. Migration can be usefully contrasted with concept of ‘imperialism’, that has been influentially discussed in the context of geographical econ…Read more
  •  93
    There is currently much discussion about how decision making should proceed when an agent's degrees of belief are imprecise; represented by a set of probability functions. I show that decision rules recently discussed by Sarah Moss, Susanna Rinard and Rohan Sud all suffer from the same defect: they all struggle to rationalize diachronic ambiguity aversion. Since ambiguity aversion is among the motivations for imprecise credence, this suggests that the search for an adequate imprecise decision ru…Read more
  •  788
    Dutch Book Arguments and Imprecise Probabilities
    In Dennis Dieks, Stephan Hartmann, Michael Stoeltzner & Marcel Weber (eds.), Probabilities, Laws and Structures, Springer. 2012.
  •  769
    Scientific Uncertainty: A User's Guide
    Grantham Institute on Climate Change Discussion Paper. 2012.
    There are different kinds of uncertainty. I outline some of the various ways that uncertainty enters science, focusing on uncertainty in climate science and weather prediction. I then show how we cope with some of these sources of error through sophisticated modelling techniques. I show how we maintain confidence in the face of error.
  •  302
    Should subjective probabilities be sharp?
    Episteme 11 (3): 277-289. 2014.
    There has been much recent interest in imprecise probabilities, models of belief that allow unsharp or fuzzy credence. There have also been some influential criticisms of this position. Here we argue, chiefly against Elga (2010), that subjective probabilities need not be sharp. The key question is whether the imprecise probabilist can make reasonable sequences of decisions. We argue that she can. We outline Elga's argument and clarify the assumptions he makes and the principles of rationality he…Read more
  •  114
    Laplace's demon and the adventures of his apprentices
    with Roman Frigg, Hailiang Du, and Leonard A. Smith
    Philosophy of Science 81 (1): 31-59. 2014.
    The sensitive dependence on initial conditions (SDIC) associated with nonlinear models imposes limitations on the models’ predictive power. We draw attention to an additional limitation than has been underappreciated, namely, structural model error (SME). A model has SME if the model dynamics differ from the dynamics in the target system. If a nonlinear model has only the slightest SME, then its ability to generate decision-relevant predictions is compromised. Given a perfect model, we can take …Read more
  •  45
    "Chance" crops up all over philosophy, and in many other areas. It is often assumed -- without argument -- that chances are probabilities. I explore the extent to which this assumption is really sanctioned by what we understand by the concept of chance.
  •  90
    Uncertainty, Learning, and the “Problem” of Dilation
    with Katie Siobhan Steele
    Erkenntnis 79 (6): 1287-1303. 2014.
    Imprecise probabilism—which holds that rational belief/credence is permissibly represented by a set of probability functions—apparently suffers from a problem known as dilation. We explore whether this problem can be avoided or mitigated by one of the following strategies: (a) modifying the rule by which the credal state is updated, (b) restricting the domain of reasonable credal states to those that preclude dilation
  •  40
    Probabilistic forecasting: why model imperfection is a poison pill
    with Roman Frigg, Reason L. Machete, and Leonard A. Smith
    In Hanne Andersen, Dennis Dieks, Wenceslao Gonzalez, Thomas Ubel & Gregory Wheeler (eds.), New Challenges to Philosophy of Science, . pp. 479-492. 2013.
    This volume is a serious attempt to open up the subject of European philosophy of science to real thought, and provide the structural basis for the interdisciplinary development of its specialist fields, but also to provoke reflection on the idea of ‘European philosophy of science’. This efforts should foster a contemporaneous reflection on what might be meant by philosophy of science in Europe and European philosophy of science, and how in fact awareness of it could assist philosophers interpre…Read more
  •  56
    Nonclassical Probability and Convex Hulls
    Erkenntnis 82 (1): 87-101. 2017.
    It is well known that the convex hull of the classical truth value functions contains all and only the probability functions. Work by Paris and Williams has shown that this also holds for various kinds of nonclassical logics too. This note summarises the formal details of this topic and extends the results slightly.
  •  31
    Vague Chance?
    Ergo: An Open Access Journal of Philosophy 3. 2016.
  •  272
    This paper considers a puzzling conflict between two positions that are each compelling: it is irrational for an agent to pay to avoid `free' evidence before making a decision, and rational agents may have imprecise beliefs and/or desires. Indeed, we show that Good's theorem concerning the invariable choice-worthiness of free evidence does not generalise to the imprecise realm, given the plausible existing decision theories for handling imprecision. A key ingredient in the analysis, and a potent…Read more
  •  109
    Modelling Inequality
    with Karim Thébault and Alexander Reutlinger
    British Journal for the Philosophy of Science 69 (3): 691-718. 2018.
    Econophysics is a new and exciting cross-disciplinary research field that applies models and modelling techniques from statistical physics to economic systems. It is not, however, without its critics: prominent figures in more mainstream economic theory have criticized some elements of the methodology of econophysics. One of the main lines of criticism concerns the nature of the modelling assumptions and idealizations involved, and a particular target are ‘kinetic exchange’ approaches used to mo…Read more
  •  34
    In a recent paper, Samir Okasha presented an argument that suggests that there is no rational way to choose among scientific theories. This would seriously undermine the view that science is a rational entreprise. In this paper I show how a suitably nuanced view of what scientific rationality requires allows us to avoid Okasha’s conclusion. I go on to argue that making further assumptions about the space of possible scientific theories allows us to make scientific rationality more contentful. I …Read more
  •  48
    In this paper we argue that there is a problem with the conjunction of David Lewis' account of counterfactual conditionals and his account of laws of nature. This is a pressing problem since both accounts are individually plausible, and popular.
  •  84
    Constraints on Rational Theory Choice
    British Journal for the Philosophy of Science 68 (3): 639-661. 2017.
    ABSTRACT In a recent article, Samir Okasha presented an argument that suggests that there is no rational way to choose among scientific theories. This would seriously undermine the view that science is a rational enterprise. In this article, I show how a suitably nuanced view of what scientific rationality requires allows us to sidestep this argument. In doing so, I present a new argument in favour of voluntarism of the type favoured by van Fraassen. I then show how such a view of scientific rat…Read more