On rates of convergence for sample average approximations without smoothness
Abstract
Sample average approximation (SAA) replaces an intractable expected objective by an empirical average and is a basic device of modern stochastic optimization. We develop a rate theory for optimal values and empirical -minimizers that does not assume continuity, lower semicontinuity, or smooth perturbation structure of the sample objectives. Working on with the Hoffmann--J{\o}rgensen outer-probability formalism, we show that uniform control of the empirical objective process transfers deterministically to convergence rates for optimal values, excess risks of empirical -minimizers, and, under a sharp-growth condition, distances to the expected objective solution set. Combined with the directional differentiability of the infimum functional, this yields weak limits for empirical optimal values at the scale. Combined with LILs and maximal inequalities, it yields outer almost-sure and outer-mean rates. The definability, envelope, and VC-subgraph hypotheses are verified for definable discontinuous or non-Lipschitz classes arising in direct -- classification, fixed-architecture neural networks, threshold regression, and non-Lipschitz -type objectives with rational . Practical sufficient conditions for measurability hypotheses are discussed. Together, the framework extends continuity-based SAA theory to a tame-topological setting.
Cite
@article{arxiv.2604.25153,
title = {On rates of convergence for sample average approximations without smoothness},
author = {Hien Duy Nguyen and Jacob Westerhout and Xin Guo},
journal= {arXiv preprint arXiv:2604.25153},
year = {2026}
}