Memoryless Reigns of the “Sons of Heaven”

Human lifetimes have increasing failure rates; as people age (beyond early childhood) they are more likely to die. Viewing the succession of Chinese Emperors as a statistical ensemble we show that, unlike lifetimes, their reigns ceased at a constant rate for over two millennia, unaffected by elapsed time. In fact reign lengths of the “Sons of Heaven”, as the Chinese Emperors were known, followed a memoryless exponential distribution with a 10-year half-life. Becoming emperor not only influenced the duration of remaining life, but length of rule was independent of age at ascent. We propose an explanation for the observed exponentiality using asymptotic results from the theory of stationary stochastic processes.     

Random Effects Misspecification Can Have Severe Consequences for Random Effects Inference in Linear Mixed Models

There has been considerable and controversial research over the past two decades into how successfully random effects misspecification in mixed models (i.e. assuming normality for the random effects when the true distribution is non‐normal) can be diagnosed and what its impacts are on estimation and inference. However, much of this research has focused on fixed effects inference in generalised linear mixed models. In this article, motivated by the increasing number of applications of mixed models where interest is on the variance components, we study the effects of random effects misspecification on random effects inference in linear mixed models, for which there is considerably less literature. Our findings are surprising and contrary to general belief: for point estimation, maximum likelihood estimation of the variance components under misspecification is consistent, although in finite samples, both the bias and mean squared error can be substantial. For inference, we show through theory and simulation that under misspecification, standard likelihood ratio tests of truly non‐zero variance components can suffer from severely inflated type I errors, and confidence intervals for the variance components can exhibit considerable under coverage. Furthermore, neither of these problems vanish asymptotically with increasing the number of clusters or cluster size. These results have major implications for random effects inference, especially if the true random effects distribution is heavier tailed than the normal. Fortunately, simple graphical and goodness‐of‐fit measures of the random effects predictions appear to have reasonable power at detecting misspecification. We apply linear mixed models to a survey of more than 4 000 high school students within 100 schools and analyse how mathematics achievement scores vary with student attributes and across different schools. The application demonstrates the sensitivity of mixed model inference to the true but unknown random effects distribution.     

基于边限检验理论关于我国R&D投入和经济增长关系的实证研究——从分解视角的考虑

基于我国1991~2006年间数据,运用边限检验理论对我国R&D投入和经济增长之间的关系进行了实证研究,结果表明:我国R&D投入和经济增长之间存在长期的稳定关系,从短期来看,上期GDP增量和本期企业R&D投入对我国经济增长的促进作用显著;从长期关系看,企业R&D投入对经济增长的推动作用为正,而政府R&D投入、金融机构的R&D贷款对经济增长的推动作用为负。     

Does the law of one price hold in a high-inflation environment? A tale of two cities in Turkey

This study addresses the price convergence in two cities in Turkey (Istanbul and Ankara) using annual data over the three-quarters of the twentieth century (1922–1998), characterized by prevailing high inflation rates for most of the period. In contrast to the rest of the literature addressing convergence in price levels with a typical result of extremely slow convergence rates at best, we argue that convergence is much easier detected in growth rates rather than levels of prices. We suggest using the bounds testing procedure of Pesaran et al. (2001) for this purpose. We find a clear-cut evidence on the existence of a common driving force behind inflation dynamics in Istanbul and Ankara – a finding that is in contrast with the results typically reported in related literature.     

Spontaneous visualization and concept evaluation

This paper proposes that customers often respond to brand extension concepts by visualizing the product. We call this process spontaneous visualization and suggest that it precedes concept evaluations. In two studies, we show that spontaneous visualization is enhanced by the fit between the parent brand and the extension category and by the ease with which the product category can be imagined. The appeal of the visualized image in turn determines whether visualization enhances or decreases concept evaluations. In addition, we find a stronger link between product evaluations and delayed choice when evaluations are based on visualization; evaluations based on visualization hence appear to be more “valid” in the sense of predicting subsequent behavior. Implications of these findings and ideas for future research are discussed.

Real-world utilization of molecular diagnostic testing and matched drug therapies in the treatment of metastatic cancers

Aims: To assess the frequency of biopsies and molecular diagnostic testing (human DNA/RNA analysis), anti-cancer drug use (genomically-matched targeted therapy [GMTT], unmatched targeted therapy [UTT], endocrine therapy [ET], and chemotherapy [CT]), and medical service costs among adults with metastatic cancer.

Methods: Adults diagnosed with metastatic breast, non-small cell lung (NSCLC), colorectal, head and neck, ovarian, and uterine cancer (2010Q1–2015Q1) were identified in the OptumHealth Care Solutions claims database and followed from first metastatic diagnosis for ≥1 month and until the end of data availability. Utilization was assessed for each cancer cohort (all and patients aged ≥65 years); per-patient-per-month (PPPM) medical service costs were assessed for all patients. Testing frequency estimates were applied to Surveillance, Epidemiology, and End Results Program data to estimate the number of untested patients (2010–2014).

Results: Patients with metastatic cancer (n?=?8,193; breast [n?=?3,414], NSCLC [n?=?2,231], colorectal [n?=?1,611], head and neck [n?=?511], ovarian [n?=?275], and uterine [n?=?151]) were 63 years old (mean), with 11.1–22.2 months of observation. Biopsy and molecular diagnostic testing frequencies ranged from 7% (uterine) to 73% (ovarian), and from 34% (head and neck) to 52% (breast), respectively. Few were treated with GMTT (breast, 11%; NSCLC, 9%; colorectal, 6%). Treatment with UTT ranged from 0.7% (uterine) to 21% (colorectal). Biopsy, diagnostic testing, and anti-cancer drug therapy were less frequent for those ≥65 years. Medical service costs (PPPM, mean) ranged from $6,618 (head and neck) to $9,940 (ovarian). The estimated number of untested new patients with metastatic cancer was 636,369 (all) and 341,397 (≥65).

Limitations: In addition to the limitations of claims analyses, diagnostic testing frequency may be under-estimated if patients underwent testing prior to study inclusion.

Conclusions: The low frequency of molecular diagnostic testing suggests there are opportunities to better inform management of patients with advanced cancer, particularly decisions to treat with GMTT.     

关于压裂支撑剂评价实验的若干思考

水力压裂是油气井增产、水井增注的有效措施,压裂支撑剂性能的好坏直接影响人工裂缝的导流能力。在从事支撑剂性能评价试验中,发现若干对支撑剂性能评价试验的影响因素。研究结果对压裂支撑剂的评价标准以及下一步有效地改进具有重要的指导意义。     

浅层出砂井地层测试工艺探讨与应用

为解决海上油井浅层出砂井中封隔器密封性和座封、出砂控制、排液方式等问题,根据浅层出砂井的地质特征,通过增加管柱重量、优选测试工具及管柱设计、排液方式等测试工艺措施,探讨了螺杆泵排液＋钻铤＋测试阀测试管柱结构的可行性,通过现场应用,该测试工艺在浅层出砂井中具有极强相容性及优越性。     

形成性评估在口语测试中的应用研究

教学评估包括终结性评估和形成性评估。与终结性评估相比,形成性评估能使教师和学生及时地获得反馈信息,改善教与学的进程,提高教育质量。通过对学生进行的为期一年的口语教学和测试研究得出如下结论：新的口语测试模式可以激发学生的学习热情,能较快地提高学生的口语能力。形成性评估在口语测试中的积极效应是毋庸置疑的。     

经济增长与外商直接投资关系研究——基于上海市数据的实证分析

本文根据1990-2005年上海市GDP与FDI的时间序列数据分析,采用线性回归分析方法研究FDI与上海市经济增长之间的关系.格兰杰因果分析表明:上海市经济增长与外商直接投资之间存在着单向因果关系,即只存在从GDP到FDI的单向因果关系.之后的方差分析表明:上海市经济增长对于外商直接投资的影响非常显著,反之却影响甚微.而二者在长期中却有着因果关联性及互动关系.为此,在吸引外资战略上要采取长期而非短期的政策.