刍议典权

典权是我国的一项固有法制度。现存完整的规范典权的法令发布于唐中叶,明清两朝律典有关典权的基本律文的内容完全相同。典权为用益物权,有担保的因素,还有债权的性格。典权的风险负担需要根据本国实际情况在立法上加以规定。在我国,典物因不可抗力灭失,典权人的典权和出典人的回赎权均告消灭,而典物重建是典权人的权利。我国大陆的典权实践基本上遵行民国时期的有关民法规则。中国典权制度的未来发展完善取决于典权的形式理性和价值理性。     

The failure of meta-analytic asymptotics for the seemingly efficient estimator of the common risk difference

We consider the case of a multicenter trial in which the center specific sample sizes are potentially small. Under homogeneity, the conventional procedure is to pool information using a weighted estimator where the weights used are inverse estimated center-specific variances. Whereas this procedure is efficient for conventional asymptotics (e. g. center-specific sample sizes become large, number of center fixed), it is commonly believed that the efficiency of this estimator holds true also for meta-analytic asymptotics (e.g. center-specific sample size bounded, potentially small, and number of centers large). In this contribution we demonstrate that this estimator fails to be efficient. In fact, it shows a persistent bias with increasing number of centers showing that it isnot meta-consistent. In addition, we show that the Cochran and Mantel-Haenszel weighted estimators are meta-consistent and, in more generality, provide conditions on the weights such that the associated weighted estimator is meta-consistent.     

Acceptance sampling based on truncated life tests for generalized Rayleigh distribution

This paper considers the problem of an acceptance sampling plan for a truncated life test when the lifetime follows the generalized Rayleigh distribution. For different acceptance numbers, confidence levels, and values of the ratio of the fixed experiment time to the specified mean life, the minimum sample sizes necessary to ensure the specified mean life are found. The operating characteristic values of the sampling plans and producer's risk are discussed. Some tables are presented and the use of the tables is illustrated by a numerical example.     

Tests in a Case–control Design Including Relatives

Abstract.  We present a new approach to handle dependencies within the general framework of case–control designs, illustrating our approach by a particular application from the field of genetic epidemiology. The method is derived for parent–offspring trios, which will later be relaxed to more general family structures. For applications in genetic epidemiology we consider tests on equality of allele frequencies among cases and controls utilizing well-known risk measures to test for independence of phenotype and genotype at the observed locus. These test statistics are derived as functions of the entries in the associated contingency table containing the numbers of the alleles under consideration in the case and the control group. We find the joint asymptotic distribution of these entries, which enables us to derive critical values for any test constructed on this basis. A simulation study reveals the finite sample behaviour of our test statistics.     

On the Distance Between Cumulative Sum Diagram and Its Greatest Convex Minorant for Unequally Spaced Design Points

Abstract.  The supremum difference between the cumulative sum diagram, and its greatest convex minorant (GCM), in case of non-parametric isotonic regression is considered. When the regression function is strictly increasing, and the design points are unequally spaced, but approximate a positive density in even a slow rate ( n ^−1/3), then the difference is shown to shrink in a very rapid (close to n ^−2/3) rate. The result is analogous to the corresponding result in case of a monotone density estimation established by Kiefer and Wolfowitz, but uses entirely different representation. The limit distribution of the GCM as a process on the unit interval is obtained when the design variables are i.i.d. with a positive density. Finally, a pointwise asymptotic normality result is proved for the smooth monotone estimator, obtained by the convolution of a kernel with the classical monotone estimator.     

A robust prediction error criterion for pareto modelling of upper tails

Estimation of the Pareto tail index from extreme order statistics is an important problem in many settings. The upper tail of the distribution, where data are sparse, is typically fitted with a model, such as the Pareto model, from which quantities such as probabilities associated with extreme events are deduced. The success of this procedure relies heavily not only on the choice of the estimator for the Pareto tail index but also on the procedure used to determine the number k of extreme order statistics that are used for the estimation. The authors develop a robust prediction error criterion for choosing k and estimating the Pareto index. A Monte Carlo study shows the good performance of the new estimator and the analysis of real data sets illustrates that a robust procedure for selection, and not just for estimation, is needed.     

Direct Inference, Probability, and a Conceptual Gulf in Risk Communication

Differences in the conceptual frameworks of scientists and nonscientists may create barriers to risk communication. This article examines two such conceptual problems. First, the logic of "direct inference" from group statistics to probabilities about specific individuals suggests that individuals might be acting rationally in refusing to apply to themselves the conclusions of regulatory risk assessments. Second, while regulators and risk assessment scientists often use an "objectivist" or "relative frequency" interpretation of probability statements, members of the public are more likely to adopt a "subjectivist" or "degree of confidence" interpretation when estimating their personal risks, and either misunderstand or significantly discount the relevance of risk assessment conclusions. If these analyses of inference and probability are correct, there may be a conceptual gulf at the center of risk communication that cannot be bridged by additional data about the magnitude of group risk. Suggestions are made for empirical studies that might help regulators deal with this conceptual gulf.     

养老计划倾向与商业养老保险需求——基于CFPS数据的实证研究

养老计划倾向作为一种行为因素，可以通过提高风险认知与管理意图，增加家庭对商业养老保险的需求。利用中国家庭追踪调查数据实证分析养老计划倾向与商业养老保险参保之间的关系，结果显示：（1）计算过养老费用的家庭会系统性地提高参保概率，计算过养老费用与否引致的参保概率差异占样本平均参保水平的40%以上；（2）养老费用计算结果也体现出逆向选择性，预计养老费用越高的家庭越倾向于参与商业养老保险；（3）养老计划倾向还会提高家庭对除商业养老保险外其他类型商业保险的需求，从而提高家庭整体商业保险参与水平。因此，提高家庭的养老计划倾向能有效促进商业养老保险市场，甚至整个商业保险市场的发展。     

证券投资基金中委托代理关系的风险研究

讨论了证券投资基金中投资人和基金管理人在委托代理关系中存在的风险问题，给出了考虑投资总收益作为单一可观测变量的委托代理模型，并进行了风险分析，提出了证券投资基金中风险防范的一些措施．     

网络财务系统的风险及防范

网络财务管理的实施面临着技术落后,内控制度不完善以及企业外部的竞争对手、网络黑客和病毒等三大风险。为此,必须重视先进技术的应用,建立半开放结构,设立安全检测预警系统;必须规范相关法律、法规,强化网络内控制度,加强会计档案管理,重视高素质人才的培养以及防范风险。