Procedural Fairness Through Decoupling Objectionable Data Generating Components
Zeyu Tang, Jialu Wang, Yang Liu, Peter Spirtes, Kun Zhang
TL;DR
The paper tackles disguised procedural unfairness by shifting fairness attention from outcomes to the data generating process itself. It introduces a Rawls-inspired framework that decouples objectionable components from neutral ones using a value instantiation rule and reference-point configurations, ensuring predictions rely only on neutral information where possible. The approach is implemented via modular local causal mechanisms and an ex post optimization to maximize the least advantaged group’s expected outcome, with experiments on simulated data and real datasets (UCI Adult, Folktables) showing improved fairness for disadvantaged groups compared to outcome-centric methods. This modular, transparent framework provides procedural guarantees on fairness of the generation process and offers a scalable path for applying fairness principles to complex causal models in decision-making tasks.
Abstract
We reveal and address the frequently overlooked yet important issue of disguised procedural unfairness, namely, the potentially inadvertent alterations on the behavior of neutral (i.e., not problematic) aspects of data generating process, and/or the lack of procedural assurance of the greatest benefit of the least advantaged individuals. Inspired by John Rawls's advocacy for pure procedural justice, we view automated decision-making as a microcosm of social institutions, and consider how the data generating process itself can satisfy the requirements of procedural fairness. We propose a framework that decouples the objectionable data generating components from the neutral ones by utilizing reference points and the associated value instantiation rule. Our findings highlight the necessity of preventing disguised procedural unfairness, drawing attention not only to the objectionable data generating components that we aim to mitigate, but also more importantly, to the neutral components that we intend to keep unaffected.
