Testing for parameter constancy in the time series direction in panel data models

We propose tests for parameter constancy in the time series direction in panel data models. We construct a locally best invariant test based on Tanaka [Time series analysis: nonstationary and noninvertible distribution theory. New York: Wiley; 1996] and an asymptotically point optimal test based on Elliott and Müller [Efficient tests for general persistent time variation in regression coefficients. Rev Econ Stud. 2006;73:907–940]. We derive the limiting distributions of the test statistics as T→∞ while N is fixed, and calculate the critical values by applying numerical integration and response surface regression. Simulation results show that the proposed tests perform well if we apply them appropriately.     

The story of Lucy: lessons learned,lessons taught

ABSTRACT

This article provides an extended case example highlighting the value of a supportive approach to practice, in addition to the importance of holding a psychodynamic developmental frame of reference. Concepts of repetition compulsion, the holding environment, and object constancy are applied to the clinical material. The case is underscored for its value as a teaching tool.     

Tests for structural breaks in memory parameters of long-memory heterogeneous autoregressive models

Tests for structural breaks in the coefficients of the long-memory heterogeneous autoregressive (HAR) models are developed. The tests are based on the partial sum process of the normalized efficient score vector. The tests have the nice property of identifying the parameters of the daily, weekly, and monthly regressors in which breaks occur. Limiting null distributions of the proposed tests are proven to be derived from standard Brownian bridges. A finite sample Monte-Carlo experiment shows reasonable size and power properties of the proposed tests. The proposed method is illustrated by a real data analysis.     

汉魏晋学术的走向与玄学的兴起

汉魏晋学术的走向是在“同”与“统”、“变”与“常”的纠结中向前推进的。不论是“三同”还是“一统”,天、道都是既变又不变 ,儒家天道必须为自身的合法性进行论证。百家之统合其实不在于学派的门户 ,而在于是否能够从理论上说明致极归一、以一会众的道理。玄学作为儒道兼综而搅起魏晋学术变革波澜的产物 ,首要的问题是如何将孔、老二圣会通起来。儒道轮替交织 ,“三玄”因变而兴起。“性与天道”玄之又玄 ,但玄虚亦需要周乎时变 ,从而走出一条既不回避孔老的对立冲突、又能将双方引向互补共济的新路。     

税收特征的哲学解读

运用对立统一规律分析了税收基本特征中存在的强制性与自愿性、无偿性收入与有偿性支出、固定性与可变性的三对矛盾。分析认为,在诸矛盾中,强制性与自愿性是主要矛盾。强制性是税收个别无偿性与整体有偿性实现的前提;为防止强制征收中的随意性,要求征税标准相对固定。当无偿性收入和有偿性支出各自达到一定数量时,二者可以相互转化。在纠正对税收特征传统认识的同时,提出通过提高公民文化素质、完善法律和提高财政支出的使用效率等方法来提高公民纳税自觉性的观点。     

论“第三代”诗人的持续性写作

20世纪80年代末期,"第三代"诗歌运动结束之后,基于个人和社会等各种原因,有的诗人选择了放弃诗歌,还有的诗人则选择留守在现场,继续自己的诗歌创作之路。经过了90年代这十年的积累和沉淀,不少诗人在新世纪又返归诗坛,重新创作。他们在新世纪的持续性写作,既可能是对80年代诗歌传统的一种精神延续,同时也深刻地影响了新世纪以来诗歌格局的形成和诗歌生态的变化。     

哲学与政治学的关系哲学

哲学是人学。这是因为在现象学意义上哲学既创造世界又创造人类,即在视界融合和效果历史双重认知条件下的解释学循环。哲学创造人的类本质,完成人类种系的本体论承诺。而创造的重任不折不扣地落在了个体人的肩上,即少数个体人的智慧基因的变异,并且在进化论的规则下变成整体性的表现性特征。但是,个体人的生产却必须由伦理化的政治学承担。于是,哲学与政治学就产生一种奇异的循环。这正是世界和宇宙发展和进化的必由之路。     

学习贯彻"三个代表"重要思想的基本要求

“三个代表”重要思想是面向21世纪的中国化的马克思主义,是实现全面建设小康社会宏伟目标的根本指针。学习贯彻“三个代表”重要思想不是对广大群众的一般要求和权宜之计,重在党的领导干部、重在实践落实、重在持之以恒。     

Assessing noninferiority: Evaluating efficacy of a new treatment without complete data

The FDA released the final guidance on noninferiority trials in November 2016. In noninferiority trials, validity of the assessment of the efficacy of the test treatment depends on the control treatment's efficacy. Therefore, it is critically important that there be a reliable estimate of the control treatment effect—which is generally obtained from historical trials, and often assumed to hold in the current setting (the assay constancy assumption). Validating the constancy assumption requires clinical data, which are typically lacking. The guidance acknowledges that “lack of constancy can occur for many reasons.” We clarify the objectives of noninferiority trials. We conclude that correction for bias, rather than assay constancy, is critical to conducting valid noninferiority trials. We propose that assay constancy not be assumed and discounting or thresholds be used to address concern about loss of historical efficacy. Examples are provided for illustration.     

Testing for Smooth Structural Changes in Time Series Models via Nonparametric Regression

Checking parameter stability of econometric models is a long‐standing problem. Almost all existing structural change tests in econometrics are designed to detect abrupt breaks. Little attention has been paid to smooth structural changes, which may be more realistic in economics. We propose a consistent test for smooth structural changes as well as abrupt structural breaks with known or unknown change points. The idea is to estimate smooth time‐varying parameters by local smoothing and compare the fitted values of the restricted constant parameter model and the unrestricted time‐varying parameter model. The test is asymptotically pivotal and does not require prior information about the alternative. A simulation study highlights the merits of the proposed test relative to a variety of popular tests for structural changes. In an application, we strongly reject the stability of univariate and multivariate stock return prediction models in the postwar and post‐oil‐shocks periods.