Multi-Output Distributional Fairness via Post-Processing

Fuente: arXiv
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Main Authors: Li, Gang, Lin, Qihang, Ghosh, Ayush, Yang, Tianbao
Format: Preprint
Published: 2024
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author Li, Gang
Lin, Qihang
Ghosh, Ayush
Yang, Tianbao
author_facet Li, Gang
Lin, Qihang
Ghosh, Ayush
Yang, Tianbao
contents The post-processing approaches are becoming prominent techniques to enhance machine learning models' fairness because of their intuitiveness, low computational cost, and excellent scalability. However, most existing post-processing methods are designed for task-specific fairness measures and are limited to single-output models. In this paper, we introduce a post-processing method for multi-output models, such as the ones used for multi-task/multi-class classification and representation learning, to enhance a model's distributional parity, a task-agnostic fairness measure. Existing methods for achieving distributional parity rely on the (inverse) cumulative density function of a model's output, restricting their applicability to single-output models. Extending previous works, we propose to employ optimal transport mappings to move a model's outputs across different groups towards their empirical Wasserstein barycenter. An approximation technique is applied to reduce the complexity of computing the exact barycenter and a kernel regression method is proposed to extend this process to out-of-sample data. Our empirical studies evaluate the proposed approach against various baselines on multi-task/multi-class classification and representation learning tasks, demonstrating the effectiveness of the proposed approach.
format Preprint
id arxiv_https___arxiv_org_abs_2409_00553
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Multi-Output Distributional Fairness via Post-Processing
Li, Gang
Lin, Qihang
Ghosh, Ayush
Yang, Tianbao
Machine Learning
Artificial Intelligence
Computers and Society
The post-processing approaches are becoming prominent techniques to enhance machine learning models' fairness because of their intuitiveness, low computational cost, and excellent scalability. However, most existing post-processing methods are designed for task-specific fairness measures and are limited to single-output models. In this paper, we introduce a post-processing method for multi-output models, such as the ones used for multi-task/multi-class classification and representation learning, to enhance a model's distributional parity, a task-agnostic fairness measure. Existing methods for achieving distributional parity rely on the (inverse) cumulative density function of a model's output, restricting their applicability to single-output models. Extending previous works, we propose to employ optimal transport mappings to move a model's outputs across different groups towards their empirical Wasserstein barycenter. An approximation technique is applied to reduce the complexity of computing the exact barycenter and a kernel regression method is proposed to extend this process to out-of-sample data. Our empirical studies evaluate the proposed approach against various baselines on multi-task/multi-class classification and representation learning tasks, demonstrating the effectiveness of the proposed approach.
title Multi-Output Distributional Fairness via Post-Processing
topic Machine Learning
Artificial Intelligence
Computers and Society
url https://arxiv.org/abs/2409.00553