关于我国劳动合同短期化的经济学思考

维护劳动者合法权益,建立和谐的劳动关系,是构建和谐社会的重要内容.当前,劳动合同短期化现象普遍存在,引起了社会的广泛关注.劳动合同短期化引发的问题不利于劳动关系的稳定以及国家社会的和谐发展.通过运用市场逆向选择,第二方执行契约和静态比较优势理论对劳动合同短期化现象进行经济学的阐释,并提出一系列解决劳动合同短期化问题的政策思路,实现劳动关系的和谐发展.     

Bayesian adaptive bandit-based designs using the Gittins index for multi-armed trials with normally distributed endpoints

Adaptive designs for multi-armed clinical trials have become increasingly popular recently because of their potential to shorten development times and to increase patient response. However, developing response-adaptive designs that offer patient-benefit while ensuring the resulting trial provides a statistically rigorous and unbiased comparison of the different treatments included is highly challenging. In this paper, the theory of Multi-Armed Bandit Problems is used to define near optimal adaptive designs in the context of a clinical trial with a normally distributed endpoint with known variance. We report the operating characteristics (type I error, power, bias) and patient-benefit of these approaches and alternative designs using simulation studies based on an ongoing trial. These results are then compared to those recently published in the context of Bernoulli endpoints. Many limitations and advantages are similar in both cases but there are also important differences, specially with respect to type I error control. This paper proposes a simulation-based testing procedure to correct for the observed type I error inflation that bandit-based and adaptive rules can induce.     

Blinded assessment of treatment effects for survival endpoint in an ongoing trial

Many assumptions, including assumptions regarding treatment effects, are made at the design stage of a clinical trial for power and sample size calculations. It is desirable to check these assumptions during the trial by using blinded data. Methods for sample size re‐estimation based on blinded data analyses have been proposed for normal and binary endpoints. However, there is a debate that no reliable estimate of the treatment effect can be obtained in a typical clinical trial situation. In this paper, we consider the case of a survival endpoint and investigate the feasibility of estimating the treatment effect in an ongoing trial without unblinding. We incorporate information of a surrogate endpoint and investigate three estimation procedures, including a classification method and two expectation–maximization (EM) algorithms. Simulations and a clinical trial example are used to assess the performance of the procedures. Our studies show that the expectation–maximization algorithms highly depend on the initial estimates of the model parameters. Despite utilization of a surrogate endpoint, all three methods have large variations in the treatment effect estimates and hence fail to provide a precise conclusion about the treatment effect. Copyright © 2012 John Wiley & Sons, Ltd.     

Sample size considerations for Japanese patients in a multi‐regional trial based on MHLW guidance

Since the publication of the International Conference on Harmonization E5 guideline, new drug approvals in Japan based on the bridging strategy have been increasing. To further streamline and expedite new drug development in Japan, the Ministry of Health, Labour and Welfare, the Japanese regulatory authority, recently issued the ‘Basic Principles on Global Clinical Trials' guidance to promote Japan's participation in multi‐regional trials. The guidance, in a Q&A format, provides two methods as examples for recommending the number of Japanese patients in a multi‐regional trial. Method 1 in the guidance is the focus of this paper. We derive formulas for the sample size calculations for normal, binary and survival endpoints. Computations and simulation results are provided to compare different approaches. Trial examples are used to illustrate the applications of the approaches. Copyright © 2009 John Wiley & Sons, Ltd.     

关于拓展我国券商融资渠道的分析与思考

在对我国券商8种融资主渠道(增资扩股、发行中长期债券、上市发行股票、国债回购、股票质押贷款、银行间同业拆借、短期金融券和资产管理业务等)进行分析的基础上,提出从提高券商信用、创新金融工具、建立证券金融公司、推动券商间战略重组等4个方面消除券商融资障碍、进一步拓展融资渠道的对策建议。     

从认知心理学角度谈外语学习过程中的记忆

外语学习是一种极为复杂的、特殊的认知过程。人们掌握外语和运用外语的能力都是通过学习过程习得的,而这一学习过程与认知心理学密切相关。文章运用语言的心理机制理论,试从记忆的功能和记忆的结构两个角度深入论述外语学习过程中的记忆,以期改进学习者在外语学习上的技巧和策略,从而提高学习者的外语水平。     

英语教育专业“短学期”实践教学的研究与实践

＂短学期＂实践教学是贯彻本科英语教学大纲精神的一项创新性举措,是课堂教学的延伸和扩展。以邯郸学院英语教育专业＂短学期＂实践教学为例,提出了＂短学期＂实践教学应具备创新性实践、合作性实践、学术性实践和教育性实践的特征;针对当前＂短学期＂实践教学存在的突出问题,从加强教师教学微技能的训练、转变教师角色、制定多元化成绩评定体系、开展教学研究、建立科学的课程管理体系五个方面提出了加强＂短学期＂实践教学的建议。     

基于HP滤波模型的农产品价格波动分析——以水果为例

运用2001-2011年的鲜果零售价格数据,分析了我国水果价格波动主要特征,运用X11季节调整模型实证分析季节性因素对我国水果价格波动的影响;运用HP滤波分解模型将2001—2011年我国水果价格指数序列分解为趋势值序列和波动值序列,据此考察我国水果价格长期波动的趋势,并对短期波动的周期进行划分。研究发现:我国水果价格具有稳步上涨的长期趋势,但季节性因素、不可观测性因素及国际经济因素会使价格在短期内剧烈波动;此外,研究期内我国水果价格波动可划分为7个周期,各周期持续的时间长度、谷-峰落差都不尽相同,研究末期水果价格波动的幅度和频率都明显提高。提出为了稳定我国水果价格,有必要从生产、消费及进口方面采取针对性措施对水果价格加以调控。     

A Legal Structure for Limiting the Agency Cost of Stock Rights Transfer

股权表决权能的单独处分会减损其他股东的福利，资本多数决之下限制或者禁止股权转让的合约安排可能会侵害股东的退出权，进而减损股权市场对高管的制约力量，间接推高管理层滥权谋私的代理成小。在创设股权转让的法律结构时，必须任合约自由、资本多数决与降低代理成本之间求取妥当的平衡。法官应认定投票权转让行为无效，以保证投票权与剩余索取权匹配，并保持股东投票权之于高管的约束功能。章程概括性地禁止股权转让，阻塞了股东退出权，不利于遏制控股股东与高管潜在的滥权行为，当属无效。法官必须本着长期契约与短期契约、章程初始条款及修订条款的差异化视角，区分各类限制股权转让的章程约定的效力。     

有期徒刑分等的机能与依据——以刑事立法与行刑的不同范式为视角

有期徒刑等级的划分应以修正的刑罚分配主义为指导。在立法阶段,有期徒刑的轻重等级划分具有标示罪行轻重的形式机能,应以5年和10年作为轻等、中等与重等有期徒刑的界点;在行刑阶段,有期徒刑的长短期划分具有标示不同期限自由刑改造效果的实质机能,应以1年和15年作为短期、中期与长期有期徒刑的界点。