论成品油定价机制中的有限规制：基于合谋的视角

利用单期静态博弈分析法、有限期动态博弈分析法和无限期动态博弈分析法对成品油定价机制中寡头厂商的合谋行为进行了分析。研究发现：两家寡头厂商在合谋条件下的收益均高于双方各自独立定产条件下的收益，因此，双方存在进行价格合谋的利益激励。基于此，我国成品油价格形成机制的改革可以考虑采用有限规制等手段。     

Generalizing the standardized hazard ratio to multivariate proportional hazards regression,with an application to clinical~genomic studies

The standardized hazard ratio for univariate proportional hazards regression is generalized as a scalar to multivariate proportional hazards regression. Estimators of the standardized log hazard ratio are developed, with corrections for bias and for regression to the mean in high-dimensional analyses. Tests of point and interval null hypotheses and confidence intervals are constructed. Cohort sampling study designs, commonly used in prospective–retrospective clinical genomic studies, are accommodated.     

基于多维效应的能源效率评估理论——以非参数DEA方法为例

基于多维效应的能源效率评估使人们在达到经济增长目的的同时兼顾能源安全、竞争力、环境、社会和技术的可持续性。论述能源效率内涵演化发展的路径，在此基础上将能源效率的内涵扩展至多维效应。以非参数DEA（Data Envelopment Analysis）方法为例，研究基于多维效应的能源效率评估方法的演化与发展趋势。研究结果显示:采用DEA方法对基于多维效应的能源效率进行评估的发展趋势主要有以下3点:能源效率的内涵不断延伸；DEA模型向非导向非径向模型转变；能源效率评估的研究维度不断扩展。对多维效应的能源效率综合指标评价体系和评价方法还需做深入研究。     

Asymptotically optimal shrinkage estimates for non-normal data

Motivated by several practical issues, we consider the problem of estimating the mean of a p-variate population (not necessarily normal) with unknown finite covariance. A quadratic loss function is used. We give a number of estimators (for the mean) with their loss functions admitting expansions to the order of p ^?1/2 as p→∞. These estimators contain Stein's [Inadmissibility of the usual estimator for the mean of a multivariate normal population, in Proceedings of the Third Berkeley Symposium in Mathematical Statistics and Probability, Vol. 1, J. Neyman, ed., University of California Press, Berkeley, 1956, pp. 197–206] estimate as a particular case and also contain ‘multiple shrinkage’ estimates improving on Stein's estimate. Finally, we perform a simulation study to compare the different estimates.     

节目试看对网络视频运营商市场策略影响研究

随着网络视频运营商收费节目试看的兴起，而节目试看对网络视频运营商诸如市场规模，利润等市场策略的影响所知甚少。本文在考虑网络用户情绪效用情况下，通过构建高质量视频运营商首播节目与后来跟进的低质量视频运营商播出该节目的博弈模型，研究高质量视频运营商首播节目之前提供节目试看对两个运营商收费模式下的节目最优收费价格和免费模式下的最优嵌入广告量以及视频节目提供模式选择的影响。研究表明，高质量视频运营商在节目首播之前提供节目充分试看能够实现节目最优收费价格最高，利润最大，因此节目充分试看是其最优策略；并且低质量运营商在其单位广告收益与用户单位广告"成本"满足一定条件下，高质量运营商提供的节目的充分试看能够减少低质量运营商总利润，因此避免低质量视频运营商搭乘节目试看的顺风车；高质量视频运营商提供节目充分试看情况下，高质量视频运营商只采取收费模式为其最优市场策略，低质量视频运营商采取免费模式为其最优市场策略。本文的研究成果对网络视频运营商日常运营有一定的管理学启示与应用价值。     

Utilizing Bayesian predictive power in clinical trial design

The Bayesian paradigm provides an ideal platform to update uncertainties and carry them over into the future in the presence of data. Bayesian predictive power (BPP) reflects our belief in the eventual success of a clinical trial to meet its goals. In this paper we derive mathematical expressions for the most common types of outcomes, to make the BPP accessible to practitioners, facilitate fast computations in adaptive trial design simulations that use interim futility monitoring, and propose an organized BPP-based phase II-to-phase III design framework.     

Early stopping in seamless phase I/II clinical trials

In recent years, seamless phase I/II clinical trials have drawn much attention, as they consider both toxicity and efficacy endpoints in finding an optimal dose (OD). Engaging an appropriate number of patients in a trial is a challenging task. This paper attempts a dynamic stopping rule to save resources in phase I/II trials. That is, the stopping rule aims to save patients from unnecessary toxic or subtherapeutic doses. We allow a trial to stop early when widths of the confidence intervals for the dose-response parameters become narrower or when the sample size is equal to a predefined size, whichever comes first. The simulation study of dose-response scenarios in various settings demonstrates that the proposed stopping rule can engage an appropriate number of patients. Therefore, we suggest its use in clinical trials.     

Cultural metaphors as means to contextualised understanding of child and childhood

The conceptualizations about children and childhoods enrich our understanding of adult–child interactions, educational practice, policy and child-welfare interventions. This study explored 42 cultural metaphors drawn from diverse socio-economic, geographical and linguistic settings to construct Indian childhoods. The paper reports an interpretative analysis of reconstructions leading to a typology of metaphors-in-use. The conceptual-analytical exercise helped unpack nuances and contextual meanings of metaphors. The paper argues for richness and subtlety in theorising childhoods, which is multilayered, situated and intertwined with contextual issues and tensions. The study offers methodological, pedagogical and conceptual insights and proposes possibilities for using cultural tools into inquiring childhoods.     

Response‐adaptive designs for binary responses: How to offer patient benefit while being robust to time trends?

Response‐adaptive randomisation (RAR) can considerably improve the chances of a successful treatment outcome for patients in a clinical trial by skewing the allocation probability towards better performing treatments as data accumulates. There is considerable interest in using RAR designs in drug development for rare diseases, where traditional designs are not either feasible or ethically questionable. In this paper, we discuss and address a major criticism levelled at RAR: namely, type I error inflation due to an unknown time trend over the course of the trial. The most common cause of this phenomenon is changes in the characteristics of recruited patients—referred to as patient drift. This is a realistic concern for clinical trials in rare diseases due to their lengthly accrual rate. We compute the type I error inflation as a function of the time trend magnitude to determine in which contexts the problem is most exacerbated. We then assess the ability of different correction methods to preserve type I error in these contexts and their performance in terms of other operating characteristics, including patient benefit and power. We make recommendations as to which correction methods are most suitable in the rare disease context for several RAR rules, differentiating between the 2‐armed and the multi‐armed case. We further propose a RAR design for multi‐armed clinical trials, which is computationally efficient and robust to several time trends considered.     

Enacting reflective and deliberative practices in action research

ABSTRACT

We consider action research as a form of deliberative policy analysis. This analysis explores a “reconstruction clinic” in which stakeholders and public officials engaged memories, hopes and obligations as they sought to resolve controversies over details of policy implementation. We ask how institutional design shaped participants’ reflective and deliberative progress. Reflection in action can prompt not only changes in cognitive frames, but new behavioural capacities for action. Deliberative practices can shape new relationships between parties through the work of apology, recognition, appreciation, and emergent collaboration.