A Necessary Condition for the Strong Oracle Property

A problem of using a non‐convex penalty for sparse regression is that there are multiple local minima of the penalized sum of squared residuals, and it is not known which one is a good estimator. The aim of this paper is to give a guide to design a non‐convex penalty that has the strong oracle property. Here, the strong oracle property means that the oracle estimator is the unique local minimum of the objective function. We summarize three definitions of the oracle property – the global, weak and strong oracle properties. Then, we give sufficient conditions for the weak oracle property, which means that the oracle estimator becomes a local minimum. We give an example of non‐convex penalties that possess the weak oracle property but not the strong oracle property. Finally, we give a necessary condition for the strong oracle property.     

Combining Inverse Probability Weighting and Multiple Imputation to Improve Robustness of Estimation

Inverse probability weighting (IPW) and multiple imputation are two widely adopted approaches dealing with missing data. The former models the selection probability, and the latter models data distribution. Consistent estimation requires correct specification of corresponding models. Although the augmented IPW method provides an extra layer of protection on consistency, it is usually not sufficient in practice as the true data‐generating process is unknown. This paper proposes a method combining the two approaches in the same spirit of calibration in sampling survey literature. Multiple models for both the selection probability and data distribution can be simultaneously accounted for, and the resulting estimator is consistent if any model is correctly specified. The proposed method is within the framework of estimating equations and is general enough to cover regression analysis with missing outcomes and/or missing covariates. Results on both theoretical and numerical investigation are provided.     

历史地理学研究中GIS的认知过程及其人类因素考量

GIS技术在历史地理学研究领域的引入,为21世纪历史地理学沉淀积累和蓄势待发提供了新的研究视角和路径。随着GIS技术的普遍运用,尤其是在历史自然地理领域的使用,遂成为该研究方向创新和发展的重要因素。不过,GIS技术在人文地理研究领域中的运用情况则略显滞后,其实质在于受人类因素影响下历史文献数据化的标准问题。此外,GIS技术自身定位不再局限于一种研究手段,而是呈现出向新方法和理论高度的认知过程。     

购物中心的商户关系研究

本文基于共生理论尝试性的对购物中心内商户间的相互关系进行了研究,论文选取了竞争、寄生与互惠这三种主要关系进行分析,提出以服饰类和珠宝类商户为代表的同质商户存在着同业聚集的经济效应,这时的同业竞争相对经济效应而言属于次要地位;主力店的选择和自身所处的位置决定了寄生关系的存在与作用大小,一部分非主力店能够凭借自身的吸引力获得客流;在异质商户之间,消耗性生活便利品与超市具有高度互补性,另外百货店与衣服鞋类专卖店也具有高互补性;但是消耗性生活用品与百货店,专卖店与超市的互补性都较低。     

我国金融控股公司立法必要性探析

金融控股公司作为我国金融“分业”体制下实现“混业经营”目的的一种组织创新模式,在我国的发展日益迅速,而我国立法空缺的现状却严重阻碍了其健康发展,也造成了极大的金融风险。文章利用历史分析、比较分析和法经济学的方法,通过对我国金融业历史发展演进的纵向考察,对世界金融控股公司普遍立法现状的横向比较以及金融控股公司作为一种经济组织形式与我国金融立法关系的分析,论证了我国金融控股公司立法的必要性。     

和谐社会与我国行政诉讼制度的发展

行政诉讼是政府和公众之间"利益沟通"的最为权威、正式的法律机制.现阶段,我国的行政诉讼呈现出起诉和受理难、应诉难、审理难、诉讼成本高、当事人胜诉难、执行难等困境,只有通过系统的制度改造,行政诉讼才能真正成为构筑和谐社会的司法公器.     

西部城市公用事业运营模式改革的路径选择——以西部三省(陕西、甘肃、四川)为例

一、引言 城市公用事业是城市为市民提供基础设施和公共服务的重要内容,包括城市供水、供电、供热、供气、公共交通、排水、污水处理、道路桥梁、市政设施、市容卫生、垃圾处理和城市绿化等方面.城市公用事业是城市经济社会发展的载体,直接关系到社会的公共利益和可持续发展.     

城市滨水旧住区问题分析及对策研究——以上海市长风新村街道沿河旧住区为例

一、引言 进入21世纪以来,城市滨水地区由于其悠久的发展历史、丰厚的文化底蕴和重要的城市区位,成为政府、公众和开发商关注的焦点,因此,滨水地带的复兴成为中国城市发展的中心议题之一.     

Labor force participation and juvenile delinquency in Taiwan: a time series analysis

This study examines the null hypothesis of Granger no-causality between labor force participation (LFP) and juvenile delinquency in Taiwan. In order to explore this issue more thoroughly, this study adopts the approach proposed by Toda and Yamamoto (1995, Journal of Econometrics, 66(1–2), 225–250). It uses official time-series data provided by the Government of Taiwan. After estimating both a four- and five-variable VAR system, one that substitutes both male and female LFP rates for the aggregate LFP rate, the primary findings of this study reveal the following: The higher the past juvenile crime rate, the lower the future aggregate and female LFP rate will be. In addition, the higher the past male LFP rate, the higher the future juvenile crime rate will be. These findings are quite robust in terms of different lag-length structures.

海派作家笔下的肺结核病人

从西方浪漫派开始,肺结核病被想象成一种爱情病。肺结核病人往往被描写成浪漫、温情、执着、优雅、多愁、善感,大部分是具有艺术修养的人。浪漫的肺结核疾病意象,多表现在女性人物身上,而男性患者则被描绘成暴躁、肮脏和可怜的。关于女病人海派作家延续了林黛玉病态美的传统审美旨趣。同时,病人形象是男性知识者无法改变生存处境,无力抢夺心爱的女性的一种阉割焦虑的心理体现。张爱玲塑造了一个异质的女肺结核病人的形象。川常不仅仅是作家弃儿情结的反映,它反映了新女性在独立之后无所依托的孤独感。