Causal emergence from effective information: Neither causal nor emergent?

Abstract

The past few years have seen several novel information-theoretic measures of causal emergence developed within the scientific community. In this paper I will introduce one such measure, called ‘effective information’, and describe how it is used to argue for causal emergence. In brief, the idea is that certain kinds of complex system are structured such that an intervention characterised at the macro-level will be more informative than one characterised at the micro-level, and that this constitutes a form of causal emergence. Having introduced this proposal, I will then assess the extent to which it is genuinely ‘causal’ and/or ‘emergent’, and argue that it supports only an epistemic form of causal emergence that is not as exciting as it first seems.