Published online by Cambridge University Press: 01 January 2022
Algorithmic information theory gives an idealized notion of compressibility that is often presented as an objective measure of simplicity. It is suggested at times that Solomonoff prediction, or algorithmic information theory in a predictive setting, can deliver an argument to justify Occam’s razor. This article explicates the relevant argument and, by converting it into a Bayesian framework, reveals why it has no such justificatory force. The supposed simplicity concept is better perceived as a specific inductive assumption, the assumption of effectiveness. It is this assumption that is the characterizing element of Solomonoff prediction and wherein its philosophical interest lies.
For valuable feedback on several versions and presentations of this article, I am indebted to Peter Grünwald, Jan-Willem Romeijn, the members of the Groningen PCCP seminar, Simon Huttegger, Hannes Leitgeb, Samuel Fletcher, Filippo Massari, Teddy Seidenfeld, and an anonymous referee. This research was supported by NWO Vici project 639.073.904.