š¤ AI Summary
This paper addresses inference for parameters defined by multivariate three-sample U-statisticsāsuch as the volume under the ROC surface (VUS) in multi-class classificationāwhere conventional asymptotic approximations suffer from poor coverage and high computational cost. We propose a jackknife pseudo-value-based empirical likelihood (JEL) framework, the first to extend empirical likelihood to multivariate three-sample U-statistics. Under mild regularity conditions, the proposed JEL ratio statistic follows a Wilks-type chi-square asymptotic distribution, obviating explicit variance estimation and computationally intensive resampling. Monte Carlo simulations demonstrate that our method achieves coverage probabilities closer to nominal levels than normal approximation or kernel-based approaches, while reducing computation time substantially. Empirical evaluation on real classification datasets confirms its robustness and practical utility. Key contributions include: (i) theoretical innovationāa novel inferential framework with rigorous asymptotic theory; (ii) methodological advantagesāvariance-free and resampling-free inference; and (iii) applied impactāsimultaneous improvements in accuracy and efficiency for VUS inference.
š Abstract
We develop a jackknife empirical likelihood (JEL) framework for inference on parameters defined through multivariate three-sample U-statistic. From three independent multivariate samples, we construct JEL ratio statistic based on suitable jackknife pseudo-values and, under mild regularity conditions, establish a Wilks-type result showing that the log JEL ratio converges in distribution to a chi-square limit. This provides asymptotically valid confidence intervals for the parameter of interest without explicit variance estimation or heavy resampling. To illustrate the usefulness of the proposed method, we construct confidence intervals for differences in volume under the surface (VUS) measures, which are widely used in classification problems. Through Monte Carlo simulations, we compare the performance of JEL-based confidence intervals with those obtained from normal approximation of U-statistic and kernel-based methods. The findings indicate that the proposed JEL approach outperforms existing methods in terms of coverage probability and computational efficiency. Finally, we apply our methods to a recent real dataset.