CAS: A Causal Attribution Score for Local and Global Explainable Artificial Intelligence
This study addresses the challenge that existing predictive explanation methods conflate predictive importance with drivers of heterogeneous causal effects, thereby failing to attribute outcomes to genuine intervention effects. To resolve this, the authors propose a causal Shapley attribution framework grounded in intervention coalition games, integrated with DoubleML causal estimation to construct a local-to-global Causal Attribution Score (CAS). This approach explicitly disentangles causal effect modification from predictive contribution without altering the Shapley value formulation, enabling interpretable analysis of heterogeneous treatment effects. Empirical results demonstrate strong performance: on synthetic data, the method achieves a mean absolute error as low as 0.107; on real-world datasets—401(k) and Pennsylvania reemployment—it identifies key causal effect modifiers via Feature-CAS that markedly differ from those highlighted by conventional SHAP, substantially outperforming current baselines.