The increasing application of Artificial Intelligence and Machine Learning
models poses potential risks of unfair behavior and, in light of recent
regulations, has attracted the attention of the research community. Several
researchers focused on seeking new fairness definitions or developing
approaches to identify biased predictions. However, none try to exploit the
counterfactual space to this aim. In that direction, the methodology proposed
in this work aims to unveil unfair model behaviors using counterfactual
reasoning in the case of fairness under unawareness setting. A counterfactual
version of equal opportunity named counterfactual fair opportunity is defined
and two novel metrics that analyze the sensitive information of counterfactual
samples are introduced. Experimental results on three different datasets show
the efficacy of our methodologies and our metrics, disclosing the unfair
behavior of classic machine learning and debiasing models