A Simpler, More Compelling Money Pump with Foresight

One might think that money pumps directed at agents with cyclic preferences can be avoided by foresight. This view was challenged two decades ago by the discovery of a money pump with foresight, which works against agents who use backward induction. But backward induction implausibly assumes that the agent would act rationally and retain her trust in her future rationality even at choice nodes that could only be reached if she were to act irrationally. This worry does not apply to BI-terminating decision problems, where at each choice node backward induction prescribes a move that terminates further action. For BI-terminating decision problems, it is enough to assume that rationality and trust in rationality are retained at choice nodes reachable by rational moves. The old money pump with foresight was not BI-terminating. In this paper, we present a new money pump with foresight, one that is both BI-terminating and considerably simpler.

Bursting Bubbles? QALYs and Discrimination

The use of Quality-Adjusted Life Years (QALYs) in healthcare allocation has been criticized as discriminatory against people with disabilities. This article considers a response to this criticism from Nick Beckstead and Toby Ord. They say that even if QALYs are discriminatory, attempting to avoid discrimination – when coupled with other central principles that an allocation system should favour – sometimes leads to irrationality in the form of cyclic preferences. I suggest that while Beckstead and Ord have identified a problem, it is a misdiagnosis to lay it at the feet of an anti-discrimination principle. The problem in fact comes from a basic tension between respecting reasonable patient preferences and other ways of ranking treatment options. As such, adopting a QALY system does not solve the problem they identify.

The real puzzle of the self-torturer: uncovering a new dimension of instrumental rationality

The puzzle of the self-torturer raises intriguing questions concerning rationality, cyclic preferences, and resoluteness. Interestingly, what makes the case puzzling has not been clearly pinpointed. The puzzle, it seems, is that a series of rational choices foreseeably leads the self-torturer to an option that serves his preferences worse than the one with which he started. But this is a very misleading way of casting the puzzle. I pinpoint the real puzzle of the self-torturer and, in the process, reveal a neglected but crucial dimension of instrumental rationality.