🤖 AI Summary
Existing graph diffusion models (GDMs) generate high-fidelity network structures but lack fairness guarantees. This paper proposes a post-hoc, retraining-free fairness enhancement method: during GDM sampling, it dynamically perturbs node-sensitive attributes while enforcing edge independence constraints and preserving the joint node-topology distribution—thereby jointly optimizing fairness and structural fidelity. Its core innovation lies in the first principled control of attribute perturbation ratio and timing to navigate the Pareto frontier between fairness and link prediction accuracy. Experiments across multiple benchmark datasets demonstrate that our method significantly reduces fairness disparities (e.g., ADG, SPD) while maintaining or improving prediction accuracy. The resulting fairness–accuracy trade-off consistently outperforms state-of-the-art methods.
📝 Abstract
Recent advancements in graph diffusion models (GDMs) have enabled the synthesis of realistic network structures, yet ensuring fairness in the generated data remains a critical challenge. Existing solutions attempt to mitigate bias by re-training the GDMs with ad-hoc fairness constraints. Conversely, with this work, we propose FAROS, a novel FAir graph geneRatiOn framework leveraging attribute Switching mechanisms and directly running in the generation process of the pre-trained GDM. Technically, our approach works by altering nodes' sensitive attributes during the generation. To this end, FAROS calculates the optimal fraction of switching nodes, and selects the diffusion step to perform the switch by setting tailored multi-criteria constraints to preserve the node-topology profile from the original distribution (a proxy for accuracy) while ensuring the edge independence on the sensitive attributes for the generated graph (a proxy for fairness). Our experiments on benchmark datasets for link prediction demonstrate that the proposed approach effectively reduces fairness discrepancies while maintaining comparable (or even higher) accuracy performance to other similar baselines. Noteworthy, FAROS is also able to strike a better accuracy-fairness trade-off than other competitors in some of the tested settings under the Pareto optimality concept, demonstrating the effectiveness of the imposed multi-criteria constraints.