Core Concepts
Causal representations that preserve interventional control over a target variable while minimizing information about the input variables.
Abstract
The paper introduces the Causal Information Bottleneck (CIB) method, which extends the Information Bottleneck (IB) framework to learn representations that are causally interpretable and can be used for reasoning about interventions.
Key highlights:
- The authors propose an axiomatic definition of optimal causal representation, which extends previous definitions of optimal representation to the causal setting.
- They derive the CIB Lagrangian from these axioms, formulating the problem of optimal causal representation learning as a minimization problem.
- The CIB method produces representations that retain a chosen amount of causal information about a target variable Y while minimizing the information preserved about the input variables X.
- The authors derive a backdoor adjustment formula to compute the post-intervention distribution of the target variable given the learned representation.
- They define a notion of equivalence between representations and propose a metric to detect it in the deterministic case.
- Experimental results on three toy problems demonstrate that the CIB method can learn representations that accurately capture causality as intended.
Stats
The paper does not contain any explicit numerical data or statistics. The experiments use synthetic data generated from Structural Causal Models.
Quotes
"To effectively study complex causal systems, it is often useful to construct representations that simplify parts of the system by discarding irrelevant details while preserving key features."
"Methods that disregard the causal structure of a system when constructing abstractions may yield results that are uninformative or even misleading, particularly when the objective is to manipulate the system or gain causal insights."