Building Socially-Equitable Public Models
Yejia Liu, Jianyi Yang, Pengfei Li, Tongxin Li, Shaolei Ren
TL;DR
This paper tackles fairness for public models that support multiple downstream agents by introducing an Equitable Objective $\mathcal{L}_{EQ}^q$, inspired by $\alpha$-fairness, to promote uniform downstream performance. It develops Equitable PM, a policy-gradient–based training algorithm that handles both differentiable and non-differentiable downstream costs and can batch experiences to optimize across agents. The authors prove that increasing $q$ improves equity in the cost-regret distribution (via variance and entropy) and provide generalization bounds linking equitable training to out-of-sample performance. Empirically, two real-world–motivated cases (data-center carbon efficiency and EV charging) show that higher $q$ yields more uniform agent outcomes and lower average regret, even if pure prediction accuracy is not minimized. The work lays a foundation for socially responsible public models that balance diverse downstream objectives while highlighting privacy, robustness, and scalability as avenues for future work.
Abstract
Public models offer predictions to a variety of downstream tasks and have played a crucial role in various AI applications, showcasing their proficiency in accurate predictions. However, the exclusive emphasis on prediction accuracy may not align with the diverse end objectives of downstream agents. Recognizing the public model's predictions as a service, we advocate for integrating the objectives of downstream agents into the optimization process. Concretely, to address performance disparities and foster fairness among heterogeneous agents in training, we propose a novel Equitable Objective. This objective, coupled with a policy gradient algorithm, is crafted to train the public model to produce a more equitable/uniform performance distribution across downstream agents, each with their unique concerns. Both theoretical analysis and empirical case studies have proven the effectiveness of our method in advancing performance equity across diverse downstream agents utilizing the public model for their decision-making. Codes and datasets are released at https://github.com/Ren-Research/Socially-Equitable-Public-Models.
