The paper introduces a new bias measure, infra-marginality, to quantify unfairness in group fairness.
problem The trade-off between group fairness and individual-level bias in decision-making.
method Proposes a new notion of -infra-marginality, proves its independence from accuracy, and provides practical methods to measure and avoid it.
result High accuracy does not lead to high infra-marginality, but maximizing group fairness often increases infra-marginality.