# A Dutch Book against Sleeping Beauties Who Are Evidential Decision Theorists

## TL;DR

This paper presents a Dutch book argument challenging evidential decision theory in the Sleeping Beauty problem, showing that both halfers and thirders are vulnerable under certain informational conditions.

## Contribution

It introduces a novel Dutch book scenario that demonstrates the limitations of evidential decision theory in symmetric informational contexts within the Sleeping Beauty problem.

## Key findings

- Evidential decision theorists can be susceptible to Dutch books in the Sleeping Beauty problem.
- The vulnerability applies to both halfers and thirders under certain informational symmetries.
- The argument extends the understanding of decision theory limitations in epistemic puzzles.

## Abstract

In the context of the Sleeping Beauty problem, it has been argued that so-called "halfers" can avoid Dutch book arguments by adopting evidential decision theory. I introduce a Dutch book for a variant of the Sleeping Beauty problem and argue that evidential decision theorists fall prey to it, whether they are halfers or thirders. The argument crucially requires that an action can provide evidence for what the agent would do not only at other decision points where she has exactly the same information, but also at decision points where she has different but "symmetric" information.