Why Approximate Coherence?

Abstract

Chapter 4 begins to answer the question of how Bayesians can justify the claim that approximating probabilistic coherence is beneficial for non-ideal thinkers. Dutch book arguments are often put forth to argue that ideal rationality requires being coherent. I show that we can justify that it is better to be less incoherent by showing that decreased incoherence is associated with decreased losses from Dutch books. While incoherent thinkers can never be immune from Dutch book losses, the amount they stand to lose, given that we standardize bet sizes, is greater the more incoherent their credences are.