🤖 AI Summary
Traditional $n$-out-of-$n$ bootstrap fails for inconsistent estimators—such as extremes, quantiles, and nonsmooth $M$-estimators—due to asymptotic non-normality. To address this, we propose an automated implementation framework for the $m$-out-of-$n$ bootstrap. Our key methodological contribution is the first systematic development of adaptive estimation procedures for both the scaling factor $ au_n$ and the optimal subsample size $m$, grounded in asymptotic theory for inconsistent estimation. We rigorously evaluate multiple $m$-selection strategies via extensive Monte Carlo simulations, assessing their finite-sample coverage accuracy for confidence intervals. Based on this framework, we develop the R package `moonboot`, enabling robust confidence interval construction for diverse inconsistent estimators. Empirical results demonstrate that our approach substantially improves actual coverage probability in small samples, while maintaining theoretical validity and practical usability.
📝 Abstract
The m-out-of-n bootstrap is a possible workaround to compute confidence intervals for bootstrap inconsistent estimators, because it works under weaker conditions than the n-out-of-n bootstrap. It has the disadvantage, however, that it requires knowledge of an appropriate scaling factor { au}n and that the coverage probability for finite n depends on the choice of m. This article presents an R package moonboot which implements the computation of m-out-of-n bootstrap confidence intervals and provides functions for estimating the parameters { au}n and m. By means of Monte Carlo simulations, we evaluate the different methods and compare them for different estimators