My work in decision theory and practical rationality deals with the question of what rationality demands when choices are made both over time and in the context of uncertainty. I have worked on the adequacy of alternatives to expected utility theory in temporally extended choice contexts. And my PhD dissertation argues that the core requirements of standard expected utility theory are requirements of instrumental rationality only for agents who desire to have stable choice dispositions over time.
In ethics, I have published on social contract theory. I am particularly interested in the use of game theory when it comes to determining the terms of the social contract. In philosophy of science, I have been concerned with the social structure of science. I have programmed an agent-based model to study the epistemic benefits from division of labour in science using Netlogo. And I have worked on the methodological question of what idealised models can teach us about the world.
Work in Progress:
Risk Writ Large (with Jonathan Weisberg)
Abstract: Risk-weighted expected utility (REU) theory is motivated by small-world problems like the Allais paradox, but it is a grand-world theory by nature. And, at the grand-world level, its ability to handle the Allais paradox is dubious. The REU model described in Risk & Rationality turns out to be risk-seeking rather than risk-averse on one natural way of formulating the Allais gambles in the grand-world context. This result illustrates a general problem with the case for REU theory, we argue. There is a tension between the small-world thinking marshaled against standard expected utility theory, and the grand-world thinking inherent to the risk-weighted alternative.
Risk Aversion and the Long Run
Abstract: While expected utility theory has problems accounting for attitudes to risk we find intuitively sensible, Buchak’s risk-weighted expected utility theory claims to offer a vindication of the ordinary decision-maker’s attitudes to risk. This paper argues that Buchak’s vindication is unsuccessful. All the examples that motivate the theory involve risk aversion for gambles with small stakes. I argue that risk aversion for such gambles is consistent with risk-weighted expected utility theory only if the agent framed her decision problem too narrowly, and thus displayed a kind of irrationality. But seeing that expected utility theory also has problems accounting for risk aversion with respect to such small stakes gambles, this paper concludes that we currently have no good account of how risk aversion for small stakes everyday gambles could be rational.
Published Papers:
On the Hidden Thought Experiments of Economic Theory (2016) in Philosophy of the Social Sciences 46 (2), pp. 129-146.
Abstract: Most papers in theoretical economics contain thought experiments. They take the form of more informal bits of reasoning that precede the presentation of the formal, mathematical models these papers are known for. These thought experiments differ from the formal models in various ways. In particular, they do not invoke the same idealized assumptions about the rationality, knowledge and preferences of agents. The presence of thought experiments in papers that present formal models, and the fact that they differ from the formal models in this way are often ignored in debates on what, if anything, we can learn from formal models in theoretical economics. I show that paying due attention to thought experiments in theoretical economics has serious implications for this debate. Differences between thought experiments and formal models are especially problematic for Sugden’s ‘credible worlds’ account.
Bargaining and the Impartiality of the Social Contract (2015) in Philosophical Studies 172 (12), pp. 3335-3355.
Abstract: The question of what a group of rational agents would agree on were they to deliberate on how to organise society is central to all hypothetical social contract theories. If morality is to be based on a social contract, we need to know the terms of this contract. One type of social contract theory, contractarianism, aims to derive morality from rationality alone. Contractarians need to show, amongst other things, that rational and self-interested individuals would agree on an impartial division of a cooperative surplus. But it is often claimed that contractarians cannot show this without introducing moral assumptions. This paper argues that on the right understanding of the question contractarians are asking, these worries can be answered. Without relying on moral assumptions, the paper offers a novel derivation of symmetry, which is the axiom responsible for the impartiality of the most famous economic bargaining solutions appealed to by contractarians.
The Epistemic Division of Labor Revisited (2015) in Philosophy of Science 82 (3), pp. 454-472. (programmed with Netlogo)
Abstract: Some scientists are happy to follow in the footsteps of others; some like to explore novel approaches. It is tempting to think that herein lies an epistemic division of labor conducive to overall scientific progress: the latter point the way to fruitful areas of research, and the former more fully explore those areas. Weisberg and Muldoon’s model, however, suggests that it would be best if all scientists explored novel approaches. I argue that this is due to implausible modeling choices, and I present an alternative ‘epistemic landscape’ model that demonstrates the alleged benefits from division of labor, with one restriction.
