{"title":"Sufficient conditions for relative aging orders of (n−k+1)-out-of-n systems","authors":"M. Kayid, M. Shrahili","doi":"10.1016/j.spl.2025.110383","DOIUrl":"10.1016/j.spl.2025.110383","url":null,"abstract":"<div><div>In this paper, we derive sufficient conditions for the preservation of relative aging orders of component lifetimes under the structure of <span><math><mrow><mo>(</mo><mi>n</mi><mo>−</mo><mi>k</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow></math></span>-out-of-<span><math><mi>n</mi></math></span> systems. Our results strengthen two relative aging properties of <span><math><mrow><mo>(</mo><mi>n</mi><mo>−</mo><mi>k</mi><mo>+</mo><mn>1</mn><mo>)</mo></mrow></math></span>-out-of-<span><math><mi>n</mi></math></span> systems obtained by Misra and Francis (2015).</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110383"},"PeriodicalIF":0.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A short memory condition for infinitely divisible random fields","authors":"Vitalii Makogin , Evgeny Spodarev","doi":"10.1016/j.spl.2025.110385","DOIUrl":"10.1016/j.spl.2025.110385","url":null,"abstract":"<div><div>This small note yields a sufficient condition for the short range dependence of measurable stationary infinitely divisible moving average random fields with <span><math><mi>d</mi></math></span>-dimensional index space. Here, the short/long range dependence concept is borrowed from the paper (Kulik and Spodarev 2021). In the special case of symmetric stable moving averages, our new condition coincides with the one from paper (Makogin et al., 2021).</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110385"},"PeriodicalIF":0.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mixingale and physical dependence equality with applications","authors":"Jonathan B. Hill","doi":"10.1016/j.spl.2025.110380","DOIUrl":"10.1016/j.spl.2025.110380","url":null,"abstract":"<div><div>We prove Wu (2005)’s physical dependence and Wu and Min (2005)’s <span><math><msub><mrow><mi>L</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>-weak dependence properties are asymmetrically equivalent to the adapted mixingale property (each implying the other with possibly different memory decay rates), and identical under geometric memory. We apply the result to two unique cases: (<span><math><mi>i</mi></math></span>) a new Gaussian approximation theory for high dimensional near epoch dependent processes, and (<span><math><mrow><mi>i</mi><mi>i</mi></mrow></math></span>) a new maximal moment inequality for <span><math><msub><mrow><mi>L</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>-physical dependent arrays when 1 <span><math><mo><</mo></math></span> <span><math><mi>p</mi></math></span> <span><math><mo><</mo></math></span> 2.</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110380"},"PeriodicalIF":0.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Necessary and sufficient conditions for the Marcĕnko–Pastur law for sample correlation matrices","authors":"Zhaorui Dong, Jianfeng Yao","doi":"10.1016/j.spl.2025.110377","DOIUrl":"10.1016/j.spl.2025.110377","url":null,"abstract":"<div><div>Necessary and sufficient conditions are found for the Marcĕnko–Pastur law to hold for a fairly general class of sample correlation matrices under different moment conditions.</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110377"},"PeriodicalIF":0.9,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Banu Baydil, Victor H. de la Peña, Haolin Zou, Heyuan Yao
{"title":"Unbiased estimation of the Gini coefficient","authors":"Banu Baydil, Victor H. de la Peña, Haolin Zou, Heyuan Yao","doi":"10.1016/j.spl.2025.110376","DOIUrl":"10.1016/j.spl.2025.110376","url":null,"abstract":"<div><div>The Gini coefficient is a fundamental statistical measure of dispersion used widely across multiple fields. The interest in the study of the properties of the Gini coefficient is highlighted by the fact that every year the World Bank ranks the level of income inequality between countries using it. In order to calculate the coefficient, it is common practice to assume a Gamma-distributed set of values when modeling the dispersion of individual incomes in a given population. The asymptotic behavior of the sample Gini coefficient for populations following a Gamma distribution has been well-documented in the literature. However, research on the finite sample behavior has been absent due to the challenge posed by the denominator. This study aims to fill this gap by demonstrating theoretically that the sample Gini coefficient is an unbiased estimator of the population Gini coefficient for a population having Gamma (<span><math><mi>α</mi></math></span>, <span><math><mi>β</mi></math></span>) distribution. Furthermore, our result provides a way to quantify the downward bias due to grouping when the population Gini coefficient is estimated using the sample Gini coefficient of equal-sized groups.</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"222 ","pages":"Article 110376"},"PeriodicalIF":0.9,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deviation inequalities for the spectral norm of structured random matrices","authors":"Guozheng Dai, Zhonggen Su","doi":"10.1016/j.spl.2025.110378","DOIUrl":"10.1016/j.spl.2025.110378","url":null,"abstract":"<div><div>We study the deviation inequality for the spectral norm of structured random matrices with non-gaussian entries. In particular, we establish an optimal bound for the <span><math><mi>p</mi></math></span>-th moment of the spectral norm by transfering the spectral norm into the suprema of canonical processes. A crucial ingredient of our proof is a comparison of weak and strong moments. As an application, we show a deviation inequality for the smallest singular value of a rectangular random matrix.</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110378"},"PeriodicalIF":0.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the increments of some extensions of the fractional Brownian motion","authors":"Charles El-Nouty","doi":"10.1016/j.spl.2025.110381","DOIUrl":"10.1016/j.spl.2025.110381","url":null,"abstract":"<div><div>Let <span><math><mrow><mo>{</mo><msub><mrow><mi>B</mi></mrow><mrow><mi>H</mi></mrow></msub><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow><mo>,</mo><mi>t</mi><mo>≥</mo><mn>0</mn><mo>}</mo></mrow></math></span> be a fractional Brownian motion with Hurst index <span><math><mrow><mn>0</mn><mo><</mo><mi>H</mi><mo><</mo><mn>1</mn></mrow></math></span>. Given that the process <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span> has stationary increments, a detailed understanding of the characteristics of small, medium, and large increments is essential. This exploration extends to the QHASI class presented as a collection of centered Gaussian processes. This class is mainly characterized by a self-similarity, a quasi-helix and an approximately stationary increments assumptions. However, the analysis of these increments requires a different approach when considering the new extension of <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span> proposed in some previous research. This investigation reveals significant differences in the behavior of increments within this extended framework.</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110381"},"PeriodicalIF":0.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Propagation of chaos for mean-field reflected BSDEs with jumps","authors":"Yiqing Lin , Kun Xu","doi":"10.1016/j.spl.2025.110382","DOIUrl":"10.1016/j.spl.2025.110382","url":null,"abstract":"<div><div>In this paper, we study a class of mean-field reflected backward stochastic differential equations (MF-RBSDEs) driven by a marked point process and also analyze MF-RBSDEs driven by a Poisson process. Based on a <span><math><mi>g</mi></math></span>-expectation representation lemma, we establish the existence and uniqueness of the particle system of MF-RBSDEs driven by a marked point process under Lipschitz generator conditions and obtain a convergence result of this system. In the Poisson setting, we obtain furthermore the convergence rate of the corresponding particle system toward the solution to the MF-RBSDEs driven by a Poisson process under bounded terminals and bounded obstacle conditions.</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110382"},"PeriodicalIF":0.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The oracle property of the generalized outcome-adaptive lasso","authors":"Ismaila Baldé","doi":"10.1016/j.spl.2025.110379","DOIUrl":"10.1016/j.spl.2025.110379","url":null,"abstract":"<div><div>The generalized outcome-adaptive lasso (GOAL) is a variable selection for high-dimensional causal inference proposed by Baldé et al. (2023). When the dimension is high, it is now well established that an ideal variable selection method should have the oracle property to ensure the optimal large sample performance. However, the oracle property of GOAL has not been proven. In this paper, we show that the GOAL estimator enjoys the oracle property. Our simulation shows that the GOAL method deals with the collinearity problem better than the oracle-like method, the outcome-adaptive lasso (OAL).</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110379"},"PeriodicalIF":0.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiwei Shi , Huisheng Shu , Chunyang Wang , Xuekang Zhang
{"title":"Parameter estimation for Cox–Ingersoll–Ross process with two-sided reflections","authors":"Yiwei Shi , Huisheng Shu , Chunyang Wang , Xuekang Zhang","doi":"10.1016/j.spl.2024.110352","DOIUrl":"10.1016/j.spl.2024.110352","url":null,"abstract":"<div><div>In this paper, the least squares estimator (LSE) for the Cox–Ingersoll–Ross process with two-sided reflections is investigated on the basis of continuous observations. The strong consistency and asymptotic normality of LSE are derived. Computer simulations and empirical analysis are performed to illustrate our theory. Moreover, we also express the regulators using local time process.</div></div>","PeriodicalId":49475,"journal":{"name":"Statistics & Probability Letters","volume":"221 ","pages":"Article 110352"},"PeriodicalIF":0.9,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}