MainFL: Intertemporal Data Valuation for Robust Auction-based Federated Learning

Auction-based Federated Learning (AFL) provides a principled framework for incentivizing data owners and allocating decentralized training resources to data consumers. However, practical AFL systems face a coupled valuation and allocation challenge: data quality is uncertain before training, post-training feedback can be strategically distorted, and heterogeneous deadlines render late model updates ineffective for learning. We propose MainFL, an incentive-compatible intertemporal data valuation mechanism for robust auction-based federated learning. MainFL integrates three components: (i) a bounded mutual-information peer prediction rule that elicits truthful pre-training quality reports without requiring ground-truth labels; (ii) an intertemporal reliability calibration scheme that updates future valuations using post-session validation signals; and (iii) a deadline-induced layered clinching mechanism that allocates quality-weighted data while enforcing budget and feasibility constraints.We theoretically establish Bayes–Nash truthfulness for data owners, allocation feasibility and budget safety, and truthful residual-demand equilibrium for data consumers under standard clinching-auction regularity conditions. Empirical results on widely used federated learning benchmarks show that MainFL improves social welfare by up to 12.1% and model accuracy by up to 7.4% compared to state-of-the-art AFL baselines, while substantially reducing straggler-induced task timeouts.