Kian Mintz-Woo

When probability discounting (or probability weighting), one multiplies the value of an outcome by one's subjective probability that the outcome will obtain in decision-making. The broader import of defending probability discounting is to help justify cost-benefit analyses in contexts such as climate change. This chapter defends probability discounting under risk both negatively, from arguments by Simon Caney (2008, 2009), and with a new positive argument. First, in responding to Caney, I argue that small costs and benefits need to be evaluated, and that viewing practices at the social level is too coarse-grained. Second, I argue for probability discounting using a distinction between causal responsibility and moral responsibility. Moral responsibility can be cashed out in terms of blameworthiness and praiseworthiness, while causal responsibility obtains in full for any effect which is part of a causal chain linked to one's act. With this distinction in hand, unlike causal responsibility, moral responsibility can be seen as coming in degrees. My argument is, given that we can limit our deliberation and consideration to that which we are morally responsible for and that our moral responsibility for outcomes is limited by our subjective probabilities, our subjective probabilities can ground probability discounting.

Parfit denies that the introduction of reasons into our ontology is costly for his theory. He puts forth two positions to help establish the claim: the Plural Senses View and the Argument from Empty Ontology. I argue that, first, the Plural Senses View for ‘exists’ can be expanded to allow for senses which undermine his ontological claims; second, the Argument from Empty Ontology can be debunked by Platonists. Furthermore, it is difficult to make statements about reasons true unless these statements include reference to objects in reality. These arguments show the instability of Parfit’s claimed metaethical advantages over naturalism. [Open access]

I discuss three families of methodologies that could be used to assign values to the normative parameters relevant to social discounting in welfare economics generally, and climate economics more specifically. First, I argue that in particular circumstances, there cannot be philosophical argumentation for normative questions; specifically, this occurs when the particular values being sought are both non-critical and from a quantitative range. Second, I argue that social preferences are insufficient if we take the problem to be normative and that proposals for informed social preferences face significant challenges in implementation. Finally, I argue in favour of expert elicitation for experts in welfare economics, construed as those who understand the theoretical implications of adopting particular judgments. Those who understand the theoretical implications of adopting particular judgments will be better placed to develop coherent social plans while integrating relevant empirical data.