Track and Tweak: Monitoring and Improving Group Fairness for Temporal Graph Neural Networks in Real Time

The prevalence of temporal networks in real-world applications, like financial transaction networks for loan approval prediction, poses significant challenges for ensuring fairness across different groups. These dynamic systems increasingly rely on Temporal Graph Neural Networks (TGNNs) to model evolving interactions between users over time, but TGNNs can inadvertently produce unfair outcomes across different demographic groups. In this work, we are the first to investigate group fairness on temporal graphs and propose a novel real-time framework for monitoring and improving group fairness in TGNNs. We begin by incorporating a fixed fairness regularization term into the TGNN framework, named FTGNN-R, which operates in real-time but exhibits several critical limitations. To address this, we propose FTGNN-M, a new monitoring-based approach that assesses fairness on the fly, without relying on unseen test data. By conducting a sensitivity analysis, FTGNN-M further identifies the specific channels of node embeddings responsible for unfairness and adaptively adjusts the corresponding subset of model parameters. This approach enables a trade-off between fairness and utility in dynamic settings. FTGNN-M offers theoretical guarantees for both fairness assessment and fairness promotion. Extensive experiments on five temporal transaction network datasets demonstrate the effectiveness of our proposed FTGNN-M model in terms of both utility and fairness metrics.