Advancing Methodological Knowledge Within State and Local Demography: a Case Study

Much of the academic literature dealing with state and local demography involves the development and evaluation of methods for estimating population. The focus on estimation methods is not surprising because they are used in many states to allocate resources. The quality control in regard to the validity and reliability afforded these methods by the traditional academic peer review process is important because, among other things, it serves to reduce the high potential for conflict that exists when resources are at stake. There are, however, methods being used by state and local demographers that have not been subject to peer review. While not necessarily unsound, these fugitive methods serve to keep the potential for conflict high because of the uncertainty regarding their validity and reliability. This paper examines just such a situation in the form of a case study. It is a discussion of a regression model developed in Nevada following the 2000 census that led to conflict over its use to estimate the population of Clark County, Nevada in 2002. The discussion reveals statistical and methodological shortcomings in this model that lead to an alternative model not subject to these shortcomings. This example illustrates how this type of analysis and discussion can lead to a wider understanding of methods on the part of practitioners through the corrective process of academic peer review. It also suggests that states in which estimates are used to allocate resources would be well-served by subjecting new methods being considered for use to academic peer review before they are adopted.     

立法后评估结果的回应机制

立法后评估结果的回应机制,就是特定的国家机关针对立法后评估报告中提出来的问题,采取特定方式作出回复或反应的具体运作过程。有效的立法后评估的回应机制建立在立法后评估结果的信度与效度上,其回应主体是立法后评估报告所涉及的有关立法与执法机关或人员,同时还要求运用特定的回应方式与内容。为保障立法后评估结果顺畅的有效回应,还需要建立完善的立法后评估结果回应的监控制度。     

新凯恩斯主义视域下中国近十年货币政策轨迹

基于开放经济新凯恩斯主义货币政策动态随机一般均衡模型的新凯恩斯主义菲利普斯曲线、动态IS曲线、新凯恩斯主义工资菲利普斯曲线,考察了不同货币政策机制对中国近十年货币政策轨迹的拟合度。通过全样本预测,发现混合规则对于中国近十年的产出缺口具有最佳的拟合度,单一的价格规则或数量规则均无法较好地拟合中国现实数据;二阶矩匹配的结果进一步证实了这一论断。     

基于评级模型的违约率估计

违约率是信用风险建模的核心输入变量,文章基于评级模型对违约率进行估计。估计违约数据很少的低违约组合的违约率是一个比较困难的问题,用最大谨慎原则方法解决这类问题时结果偏大,过于保守。文章将最大谨慎原则的思想与极大似然方法相结合,估计了低违约组合的违约率。估计的结果比仅用最大谨慎原则得到的结果很大程度上降低了保守度。     

一种估计连续策略博弈的两阶段方法

 最近实证博弈研究的迅速发展为分析市场中的策略互动、进行政策分析与反事实实验提供了有效的工具。本文提出一种估计不完全信息连续策略博弈的两阶段方法,它可以处理私有信息的影响。第一阶段通过非参数分位数回归估计局中人的策略与期望支付函数;第二阶段利用贝叶斯——纳什均衡不等式构造模拟最小距离估计量,最终获得结构参数的估计。数值模拟显示本方法有良好的小样本表现。与现有文献的嵌套固定点方法相比,本方法不需计算均衡,极大地降低了计算量,并减轻了多重均衡的干扰。本方法既可以用于估计离散状态博弈,也适用于连续状态博弈。     

On the estimation and application of max-stable processes

The theory of max-stable processes generalizes traditional univariate and multivariate extreme value theory by allowing for processes indexed by a time or space variable. We consider a particular class of max-stable processes, known as M4 processes, that are particularly well adapted to modeling the extreme behavior of multiple time series. We develop procedures for determining the order of an M4 process and for estimating the parameters. To illustrate the methods, some examples are given for modeling jumps in returns in multivariate financial time series. We introduce a new measure to quantify and predict the extreme co-movements in price returns.     

Bayesian and likelihood-based inference for the bivariate normal correlation coefficient

The paper develops some objective priors for correlation coefficient of the bivariate normal distribution. The criterion used is the asymptotic matching of coverage probabilities of Bayesian credible intervals with the corresponding frequentist coverage probabilities. The paper uses various matching criteria, namely, quantile matching, highest posterior density matching, and matching via inversion of test statistics. Each matching criterion leads to a different prior for the parameter of interest. We evaluate their performance by comparing credible intervals through simulation studies. In addition, inference through several likelihood-based methods have been discussed.     

感知实绩、顾客满意与顾客忠诚--微观层次上的审视

最近几十年来,对顾客满意-企业利润之间关系的认识不断深化,使得对顾客满意的研究得到了很大的发展.其中,顾客忠诚被认为是顾客满意影响企业利润的中介.然而,对于顾客满意影响顾客忠诚的微观过程,目前缺乏一致的结论.我们采用声誉、重复消费意向和推荐他人消费意向作为中间变量,对顾客感知实绩、满意和忠诚之间的因果联系进行了实证研究.结果表明,顾客满意同顾客忠诚之间并无直接的因果联系,因此,企业在制定市场份额策略时,不应该仅局限于提高感知实绩和顾客满意的范畴,而应从多个角度出发来提高顾客忠诚.     

Removing the singularity of a penalty via thresholding function matching

By introducing the idea of thresholding function matching, it is illustrated that both bridge penalty and log penalty can be transformed so as to circumvent certain difficulties in numerical computation and the definition of local minimality. The fact that both bridge penalty and log penalty have derivatives going to infinity at zero. This hinders their applications in statistics although it is reported in the literature that they allow recovery of sparse structure in the data under some conditions. It is illustrated in the simulation studies that in the variable selection problems, penalized likelihood estimation based on the transformed penalty obtained by the proposed thresholding function matching method outperform those based on many other state-of-art penalties, particularly when the covariates are strongly correlated. The one-to-one correspondence between the transformed penalties and their thresholding functions are also established.     

Some subjective bayesian considerations in the selection of models

Some considerations relating to the post-data selection of models are discussed. These include some difficulties with orthodox theory, implementation of the likelihood principle, and Bayesian tests of hypotheses.