实函数间断点的某些特性

本文给出了几类常见函数间断点及一般实函数第一类间断点的某些特性,并指出它们在实际问题中的应用.     

空气污染与居民心理健康——基于断点回归的估计

使用2010年和2014年中国家庭动态跟踪调查（CFPS）数据,并基于中国北方冬季集中供暖政策的准自然实验,利用断点回归方法估计空气污染对中国居民心理健康状况的影响。研究发现:（1）空气污染对居民的心理健康有显著的负面作用,通过改变空气污染指标,考虑四种不同的污染物均得出相似的结论。（2）空气污染对心理健康的负面作用大小对不同人群而言具有异质性,其中对省会城市居民、受教育程度较低的居民以及女性居民的心理健康损害程度尤为明显。（3）通过对CES-D量表中抑郁症状的分析发现,空气污染更容易导致人们情绪低落,说明空气污染不仅能通过损害人们的身体健康从而作用于其心理状况,而且能直接影响个人情绪,使人产生焦虑、不安等负面情感,对人们的心理健康带来损害。     

福柯"话语"概念之解码

话语理论家福柯在索绪尔结构语言学的基础上,提出"话语"概念。他的"话语"概念是其哲学思想的核心概念,随着其哲学思想的发展而逐步确立。首先,话语定位于以"异位"为开端的知识型的空间构型之中;其次,话语由实践性的陈述整体构成;最后,来源、间断性和离散性成为话语的主要原则。在此概念中,福柯反传统历史观、反西方现代文明的思想得到了充分展现。     

Regression Discontinuity Designs With Sample Selection

This article extends the standard regression discontinuity (RD) design to allow for sample selection or missing outcomes. We deal with both treatment endogeneity and sample selection. Identification in this article does not require any exclusion restrictions in the selection equation, nor does it require specifying any selection mechanism. The results can therefore be applied broadly, regardless of how sample selection is incurred. Identification instead relies on smoothness conditions. Smoothness conditions are empirically plausible, have readily testable implications, and are typically assumed even in the standard RD design. We first provide identification of the “extensive margin” and “intensive margin” effects. Then based on these identification results and principle stratification, sharp bounds are constructed for the treatment effects among the group of individuals that may be of particular policy interest, that is, those always participating compliers. These results are applied to evaluate the impacts of academic probation on college completion and final GPAs. Our analysis reveals striking gender differences at the extensive versus the intensive margin in response to this negative signal on performance.     

Discontinuities in robust nonparametric regression with α-mixing dependence

The main idea of the paper is to introduce a robust regression estimation method under an α-mixing dependence assumption, staying free of any parametric model restrictions while also allowing for some sudden changes in the unknown regression function. The sudden changes in the model may correspond to discontinuity points (jumps) or higher order breaks (jumps in corresponding derivatives) as well. We firstly derive some important statistical properties for local polynomial M-smoother estimates and we will propose a statistical test to decide whether some given point of interest is significantly important for a change to occur or not. As the asymptotic distribution of the test statistic depends on quantities which are left unknown we also introduce a bootstrap algorithm which can be used to mimic the target distribution of interest. All necessary proofs are provided together with some experimental results from a simulation study and a real data example.     

退休对男性老年人健康的影响--基于断点回归的实证研究

退休是个体从过去工作生涯中抽身出来的转折点，退休后个人福利的变化是老龄化社会值得关注的问题。基于中国家庭追踪调查（ CFPS）2012年数据，以男性为例采用模糊断点回归的方法识别退休对个体心理、生理健康的因果影响。结果显示，退休对个体的生理健康并没有显著影响，但对其心理健康有显著的正向效应。从影响渠道来看，退休后个体压力减少，认知功能、记忆力以及对生活满意程度提升是导致健康（尤其是心理健康）改善的主要原因。本文的研究为未来退休政策的制定提供参考。     

Early truancy intervention: Results of an evaluation using a regression discontinuity design

This study evaluates the effectiveness of a truancy reduction program. A Regression Discontinuity design was used to assess attendance outcomes for 700 children. Approximately half received a case management intervention, while the other half received a warning letter, only. Truancy rates in the control group remained at the pre-intervention levels, while truancy in the treatment group significantly declined (p < .01). Successful case closure was associated with a reduction in truancy (p < .001). The intervention was less effective with non-White children and with those who had been previously retained. Findings substantiate continued support for the intervention; however, additional resources should include culturally-responsive treatment approaches and academic enrichment programs.     

Beyond Incentives: Do Schools Use Accountability Rewards Productively?

We use a regression discontinuity design to analyze an understudied aspect of school accountability systems—how schools use financial rewards. For two years, California's accountability system financially rewarded schools based on a deterministic function of test scores. Qualifying schools received per-pupil awards amounting to about 1% of statewide per-pupil spending. Corroborating anecdotal evidence that awards were paid out as teacher bonuses, we find no evidence that winning schools purchased more instructional material, increased teacher hiring, or changed the subject-specific composition of their teaching staff. Most importantly, we find no evidence that student achievement increased in winning schools. Supplemental materials for this article are available online.     

人际-群际非连续性效应介评

人际-群际非连续性效应是指群体比个体更富竞争性的现象。针对这一现象,研究者们整合了现实冲突理论和社会认同理论,从群际互动和人际互动的差异角度提出了相应的理论解释。这些理论认为,相较于人际互动,群际互动中的博弈双方更为贪婪,且对彼此更不信任,其决策更为理性。从该理论出发,研究者们提出了减少群际冲突的几条重要途径,分别是:关注长期利益,委任强硬的领导,诱发对外群体的同情和设置超级目标。在未来的研究中,还需进一步研究这些策略如何彼此补充,以期能对建构现实社会中的群际和谐做出贡献。