cs.LGJun 22, 2026

Statistical Matching via Schrödinger Bridge beyond Conditional Independence

Authors: Eunho KooTongseok LimJinwon Sohn

Abstract

Statistical matching combines partially overlapping datasets that share covariates XX but observe the target YY and auxiliary variables ZZ separately. Classical approaches typically invoke the conditional independence assumption (CIA), which makes the problem identifiable but fundamentally implies that the imported auxiliary variable provides no additional predictive power for YY once XX is known. To capture this latent YY--ZZ dependence, we propose a novel dependency-aware Schrödinger bridge for predictive statistical matching. Our approach couples the two separated databases by tilting the conservative CIA baseline with a transportation-based compatibility cost, recovering an informative joint distribution. The resulting statistical learning framework yields full probabilistic posterior rules for bidirectional imputation. Theoretically, we establish a sufficient condition under which the learned bridge strictly improves over the CIA baseline, alongside an exact joint recovery guarantee in the Gaussian setting under an appropriate cost. Across synthetic benchmarks and real-world datasets (CelebA and Adult), we demonstrate that our dependency-aware completion consistently improves downstream predictive utility, proving especially beneficial in settings like data recoding where the underlying population exhibits strong YY--ZZ dependence.

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