The Matrix Reloaded: A Counterfactual Perspective on Bias in Machine Learning

This paper introduces a novel data-centric framework for bias analysis in machine learning, leveraging the power of counterfactual reasoning. We propose a Counterfactual Confusion Matrix, from which we derive a suite of metrics that provide a comprehensive view of a model's behaviour under counterfactual conditions. These metrics offer unique insights into the model's resilience and susceptibility to changes in sensitive attributes such as sex or race. We demonstrate their utility and complementarity with standard fairness metrics through experiments on synthetic data and known real-world datasets. Our results show that our metrics can reveal subtle biases that traditional bias evaluation strategies may overlook, providing a more nuanced understanding of potential model bias.