From Fragile to Certified: Wasserstein Audits of Group Fairness Under Distribution Shift

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ehyaei, Ahmad-Reza, Farnadi, Golnoosh, Samadi, Samira
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909816704729088
author Ehyaei, Ahmad-Reza
Farnadi, Golnoosh
Samadi, Samira
author_facet Ehyaei, Ahmad-Reza
Farnadi, Golnoosh
Samadi, Samira
contents Group-fairness metrics (e.g., equalized odds) can vary sharply across resamples and are especially brittle under distribution shift, undermining reliable audits. We propose a Wasserstein distributionally robust framework that certifies worst-case group fairness over a ball of plausible test distributions centered at the empirical law. Our formulation unifies common group fairness notions via a generic conditional-probability functional and defines $\varepsilon$-Wasserstein Distributional Fairness ($\varepsilon$-WDF) as the audit target. Leveraging strong duality, we derive tractable reformulations and an efficient estimator (DRUNE) for $\varepsilon$-WDF. We prove feasibility and consistency and establish finite-sample certification guarantees for auditing fairness, along with quantitative bounds under smoothness and margin conditions. Across standard benchmarks and classifiers, $\varepsilon$-WDF delivers stable fairness assessments under distribution shift, providing a principled basis for auditing and certifying group fairness beyond observational data.
format Preprint
id arxiv_https___arxiv_org_abs_2509_26241
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle From Fragile to Certified: Wasserstein Audits of Group Fairness Under Distribution Shift
Ehyaei, Ahmad-Reza
Farnadi, Golnoosh
Samadi, Samira
Machine Learning
Group-fairness metrics (e.g., equalized odds) can vary sharply across resamples and are especially brittle under distribution shift, undermining reliable audits. We propose a Wasserstein distributionally robust framework that certifies worst-case group fairness over a ball of plausible test distributions centered at the empirical law. Our formulation unifies common group fairness notions via a generic conditional-probability functional and defines $\varepsilon$-Wasserstein Distributional Fairness ($\varepsilon$-WDF) as the audit target. Leveraging strong duality, we derive tractable reformulations and an efficient estimator (DRUNE) for $\varepsilon$-WDF. We prove feasibility and consistency and establish finite-sample certification guarantees for auditing fairness, along with quantitative bounds under smoothness and margin conditions. Across standard benchmarks and classifiers, $\varepsilon$-WDF delivers stable fairness assessments under distribution shift, providing a principled basis for auditing and certifying group fairness beyond observational data.
title From Fragile to Certified: Wasserstein Audits of Group Fairness Under Distribution Shift
topic Machine Learning
url https://arxiv.org/abs/2509.26241