在公正与效率之间:证人出庭作证制度的困境和出路

证人出庭作证问题,涉及证明标准与法律假设、法律规则与法律标准、诉讼效率与诉讼成本、自利偏见与社会效应等诸多方面。证人不出庭作证的规范依据仍然存在、证人出庭作证的权利和义务不对等、配套措施不完善等原因,导致证人不愿意出庭。美国辩诉交易制度在很大程度上减少了开庭刑事案件的数量,其关于书面陈述的规定也减少了证人出庭作证的需求,在一定程度上实现了被告人人权保护和公共利益的平衡,值得借鉴。完善证人出庭作证制度,应以案件"客观需要"为标准,以追求事实真相为出发点,以人权保护和人性回归为落脚点,遵循限制性处罚原则和禁止利益冲突原则,提高相关规定的可操作性。因此,不宜盲目追求证人高出庭作证率。     

Testing variance components in balanced linear growth curve models

It is well known that the testing of zero variance components is a non-standard problem since the null hypothesis is on the boundary of the parameter space. The usual asymptotic chi-square distribution of the likelihood ratio and score statistics under the null does not necessarily hold because of this null hypothesis. To circumvent this difficulty in balanced linear growth curve models, we introduce an appropriate test statistic and suggest a permutation procedure to approximate its finite-sample distribution. The proposed test alleviates the necessity of any distributional assumptions for the random effects and errors and can easily be applied for testing multiple variance components. Our simulation studies show that the proposed test has Type I error rate close to the nominal level. The power of the proposed test is also compared with the likelihood ratio test in the simulations. An application on data from an orthodontic study is presented and discussed.     

Sequential estimation problems for negative exponential populations

The literature on sequential estimation problems for negative exponential populations has been reviewed here, We attempt to bring in all the published and unpublished materials known to us in a fairly coherent fashion. Both the concepts and theoretical findings are discussed.     

Testing for exponentiality against monotone failure rate average alternatives

We propose a test for exponentiality against the class of non-exponential distributions having monotone failure rate averages. The test statistic, which is a U-statistic and hence asymptotically normally distributed, is much simpler than its competitors yet compares favorably with them in efficiency and power comparisons.     

城市人口密度、国内市场规模与就业增长

我国经济“高增长、低就业”现象的原因在于我国贸易成本过高，国内市场规模较少。解决我国就业问题的关键在于减少行政干预，顺应市场要求，促进人口在空间上的适度集中，提高人口密度，提高消费效率，扩大市场规模。应进一步完善城乡一体的户籍制度，完善整合城乡劳动力市场，提高要素流动能力等。     

巧妙利用小组合作学习实现英语单元复习的高效性

比起形式丰富多彩的新授课,学生经常感到复习课枯燥乏味。为了激发学生的学习热情,在英语单元复习课上,采用小组合作学习的方式,引导学生开展各种各样的游戏和竞赛活动,使学生在宽松、愉悦的学习氛围中成功地将知识内化吸收,从而实现英语单元复习的高效性。     

Strategic Learning and the Topology of Social Networks

We consider a group of strategic agents who must each repeatedly take one of two possible actions. They learn which of the two actions is preferable from initial private signals and by observing the actions of their neighbors in a social network. We show that the question of whether or not the agents learn efficiently depends on the topology of the social network. In particular, we identify a geometric “egalitarianism” condition on the social network that guarantees learning in infinite networks, or learning with high probability in large finite networks, in any equilibrium. We also give examples of nonegalitarian networks with equilibria in which learning fails.     

带权重约束的DEA超效率评价模型及其应用研究

针对产学研协同创新项目的相对效率比较问题,数据包络分析（DEA）法是比较有效的数量分析方法。但DEA法所构建的优化模型中,由于约束条件没有充分考虑评价指标体系内部指标之间客观存在的内在权重大小信息,从而导致模型过分强调了评价单元的投入产出特征差异,甚至出现了原本非常重要的指标其权重却为0的不合理现象。本文提出DEMATEL法和数据包络分析法有机结合的思想,将运用DEMATEL法获得的指标之间内在的权重大小信息,纳入DEA法非阿基米德无穷小量ε限制的CCR模型及其超效率模型的约束条件,创新模型的可行域,构建了权重约束型ε-CCR模型和超效率ε-CCR模型。并以美国2014-2015年度国家科学基金会产学研合作研究中心发布的年度报告数据,对美国71个以高校为主导的产学研协同创新中心的相对效率进行了实证分析。实证结果显示,权重约束型超效率ε-CCR模型比没有权重约束的超效率ε-CCR模型更有效,不仅能对多个评价单位进行全排序,而且能克服无权重约束的超效率ε-CCR模型存在的评价结果不合理现象。这些结果有助于进一步推动DEA法的理论创新和应用推广,并能为多投入多产出项目的决策提供新的方法,使实际问题决策更合理更科学。     

基于历史法和零和DEA方法的用能权与碳排放权初始分配研究

本文引入了同时考虑用能权与碳排放权初始分配的零和DEA方法,从公平与效率视角对比分析了历史法与零和DEA方法两种分配方式的适用性,并应用市场交易模型检验了不同初始分配方式对各地区交易行为的影响。研究结果表明,零和DEA方法能够提高用能权与碳排放权初始分配的公平性,但却是以牺牲前沿技术效率水平为代价。其次,完善的市场机制能够提高基于零和DEA方法调配用能权与碳排放权的配置效率,生产技术水平较高的地区可以通过出售多余的用能权和碳排放权来获得额外收益,有利于促进绿色技术创新;相反,历史法容易导致高耗能、高排放的地区在初始分配中获得较多的用能权和碳排放权,不利于正向促进技术进步。最后,当市场机制不完善时,基于零和DEA方法配置用能权和碳排放权,可能会抑制技术进步,而基于历史法的初始分配方式则至少可以在短期内维持现有生产技术水平。     

基于E-NSBM模型的中国省际资源环境效率动态评价

从资源环境系统的内部结构出发,将资源环境评价体系分为生产系统和环境治理系统,针对该结构建立了扩展强自由处置性下的网络DEA模型——E-NSBM模型,将其与窗口分析法相结合,对2005-2012年中国各省资源环境效率进行了评价。结果表明：我国经济发达地区的生产系统效率普遍较高而环境治理系统效率较低;中、西部地区环境治理系统效率较高,但东部地区环境治理系统效率改进幅度最大;综合效率表现差的省份普遍表现为高的能耗强度、碳排放强度和硫强度。因此,各省应根据各自发展需要来确定资源环境效率的改进途径。