Berry-Esseen Theorem for Sample Quantiles with Locally Dependent Data
Partha S. Dey, Grigory Terlov
TL;DR
This work derives a Gaussian Central Limit Theorem for sample quantiles under locally dependent data, providing an explicit convergence rate through a reduction to sums of indicator variables and the use of Stein's method for local dependence. It establishes univariate and multivariate CLTs with concrete finite-sample bounds that depend on dependency-neighborhood sizes $D_1,D_2,D_3$, and extends naturally to joint convergence of multiple quantiles with a covariance structure $\Sigma_n$. An application to moving-average models shows Gaussian approximations hold when the MA order $q$ satisfies $q\ll n^{1/4}$, and the paper discusses potential rate-optimality, including an i.i.d. case where the rate is $O(\log n/\sqrt{n})$ and a conjectured $O(n^{-1/2})$-type refinement. Overall, the results provide practical Gaussian approximations for quantile-based statistics under broad local-dependence structures, enabling precise inference for dependent time-series quantiles. $
Abstract
We derive a Gaussian Central Limit Theorem for the sample quantiles based on locally dependent random variables with explicit convergence rate. Our approach is based on converting the problem to a sum of indicator random variables, applying Stein's method for local dependence, and bounding the distance between two normal distributions. We also generalize this approach to the joint convergence of sample quantiles with an explicit convergence rate.
