Estimation of High Dimensional Bounded Discrete Graphical Models via Regularized Generalized Score Matching

Abstract

Graphical models for multivariate count data are widely used to characterize conditional dependence structures. For count variables with unbounded support, however, ensuring a finite normalizing constant typically imposes restrictive constraints on interaction parameters. We propose bounded discrete graphical models for multivariate discrete responses with finite support, which remove such constraints by construction while retaining interpretable dependence on the observed scale. We develop a regularized generalized score matching estimator (BRIDGE), which provides a normalization-free surrogate for likelihood-based estimation. The approach yields a unified system of estimating equations for all parameters and enables joint regularization through an $\ell_1$ penalty. To address degeneracy in the loss geometry, we introduce a reparameterization that restores curvature along the intercept direction and facilitates stable computation. On the theoretical side, we analyze a nonconvex objective and establish a population separation property that replaces global convexity. This yields nonasymptotic estimation error bounds and exact support recovery in high-dimensional regimes. Simulation studies and real data analyses demonstrate that BRIDGE accurately recovers graph structure and provides a stable and interpretable framework for high-dimensional discrete graphical modeling.