博彩者特征和彩票功能悖论

一些经济学理论认为理性的人可能在一定情形下因偏好风险而参加博彩,而一些心理学实验研究则发现博彩者可能存在系统性的心理偏误。对理论的分析发现,彩票对穷人更具有吸引力且博彩者存在非理性心理。国内实证文献也支持这两个结论。如果博彩行为是非理性行为,那么博彩业就有利用人们非理性幼稚心理牟利的嫌疑。政府宣称发行彩票的目的是筹集资金用于社会公益事业,这就形成了一个悖论,即从贫穷群体那里筹集资金来改善他们的处境。     

股东派生诉讼若干问题解读

我国新《公司法》在我国初步确立了股东派生诉讼制度,规定了对股东资格的限制,提起诉讼的前置程序以及提起诉讼所依据的理由。但是有关一些问题并没有在法律上明确规定,相关的一些理论问题也亟待澄清。有必要结合域外经验与诉讼法理论的新发展对这些问题进行探讨,并提出有益的建议。     

网络微文化初探

网络微文化指的是一种进入个人互联网时代后逐渐形成并发展的注重微观和个体,以个体性、平等性为核心的价值观念和行为模式的全新社会文化现象。网络微文化在兴起和发展中有其独特的基本内涵和深远的社会影响。网络微文化的健康发展也需要国家正确的引导,包括推进高新技术的发展、发挥网络微文化的正能量和推进网络微文化健康发展的系统工程。总之,对于网络微文化的正确探索和理解已成为人文、社会学者以及相关政府决策部门需要面对的时代课题。     

Measuring the health patterns of the ‘mixed/multiple’ ethnic group in Britain: data quality problems,reporting issues,and implications for policy

The ‘mixed’ group, officially recognised in the 2001 Census, is one of the most rapidly growing ethnic groups in Britain. Although ‘mixed’ categorisation was added to ethnic coding in NHS datasets, our knowledge of health patterns for this population is meagre. Data quality problems remain a key obstacle, including poor reproducibility of the data and constraints on reporting due to sparse data bias. The consequent minimal and indicative evidence base has focused mainly on risky health behaviours, mental health and generic measures of self-rated health, as it has in the U.S.A. and Canada. There is negligible information on the main underlying causes of death, such as neoplasms, heart disease and stroke. Consideration should be given to pooling data across multiple years of health and general purpose surveys to enable reporting for the four ‘mixed’ categories and adjustment for mediating factors and relevant confounders, such as measures of socio-economic status.     

Estimates of subgroup treatment effects in overall nonsignificant trials: To what extent should we believe in them?

In drug development, it sometimes occurs that a new drug does not demonstrate effectiveness for the full study population but appears to be beneficial in a relevant subgroup. In case the subgroup of interest was not part of a confirmatory testing strategy, the inflation of the overall type I error is substantial and therefore such a subgroup analysis finding can only be seen as exploratory at best. To support such exploratory findings, an appropriate replication of the subgroup finding should be undertaken in a new trial. We should, however, be reasonably confident in the observed treatment effect size to be able to use this estimate in a replication trial in the subpopulation of interest. We were therefore interested in evaluating the bias of the estimate of the subgroup treatment effect, after selection based on significance for the subgroup in an overall “failed” trial. Different scenarios, involving continuous as well as dichotomous outcomes, were investigated via simulation studies. It is shown that the bias associated with subgroup findings in overall nonsignificant clinical trials is on average large and varies substantially across plausible scenarios. This renders the subgroup treatment estimate from the original trial of limited value to design the replication trial. An empirical Bayesian shrinkage method is suggested to minimize this overestimation. The proposed estimator appears to offer either a good or a conservative correction to the observed subgroup treatment effect hence provides a more reliable subgroup treatment effect estimate for adequate planning of future studies.     

The role of social and cognitive factors in individual gambling: An empirical study on college students

Most of the studies on the determinants of individual gambling behaviour rely on cognitive theories. In our study, we argue that, besides cognitive factors, several social factors might play an important role as well. We analyse data from an ad hoc webmail survey conducted on about 2000 undergraduate students enrolled in a large public university in the Northern Italy in the academic year 2012–13. Using a variety of statistical techniques (standard regression models, boosted regression trees and structural equations models), we show that social variables affect both participation in gambling in the past year and latent gambling propensity. In particular, controlling for several proxies for individual cognitive ability and understanding of probability, gambling propensity is positively affected by the degree of gambling in the social surrounding (parents, peers, neighbourhood) and the acceptability of gambling activities to the individual. Moreover, in our sample of college students the role of social factors appears to be larger than that of cognitive factors, and this is consistent across different types of models and specifications.     

Inappropriate Comparisons: The LGB Population's Missing Reference Group

ABSTRACT

Given that many professional organizations emphasize the need for comparing assessment results to appropriate reference groups in their codes of ethics, we consider this practice through an ecological perspective as it applies to the lesbian, gay, and bisexual (LGB) population. The purpose of norming and types of assessment bias is discussed with respect to LGB population, which frequently lack specific norming data. The authors discuss whether the LGB population has characteristics similar to other commonly normed for groups and explore how group-shared constructs such as minority stress and internalized homophobia may introduce bias and affect the validity of assessments. A social anxiety assessment as well as a personality disorder inventory are examined for bias as case examples explaining how these assessments may exhibit bias when used with the LGB population. Increases in validity and effects on treatment planning are discussed as benefits of providing LGB-specific norms. Risks of providing these norms, such as minimizing subgroup differences and possibly increasing the risk of discrimination are also addressed before providing clinicians with recommendations as to how they may minimize the risk of bias in their assessment process.     

Merging data from multiple sources: pretest and shrinkage perspectives

In this article, we have developed asymptotic theory for the simultaneous estimation of the k means of arbitrary populations under the common mean hypothesis and further assuming that corresponding population variances are unknown and unequal. The unrestricted estimator, the Graybill-Deal-type restricted estimator, the preliminary test, and the Stein-type shrinkage estimators are suggested. A large sample test statistic is also proposed as a pretest for testing the common mean hypothesis. Under the sequence of local alternatives and squared error loss, we have compared the asymptotic properties of the estimators by means of asymptotic distributional quadratic bias and risk. Comprehensive Monte-Carlo simulation experiments were conducted to study the relative risk performance of the estimators with reference to the unrestricted estimator in finite samples. Two real-data examples are also furnished to illustrate the application of the suggested estimation strategies.     

A class of exponential-type ratio estimators of a general parameter

This paper addresses the problem of estimating a general parameter using information on an auxiliary variable X. We have suggested a class of exponential-type ratio estimators for the parameter and its properties are studied. It is identified that the estimators due to Upadhyaya et al. [Journal of Statistical Theory and Practice (2011), 5(2), 285–302] and Yadav and Kadilar [Revista Columbiana de Estadistica, (2013), 36(1), 145–152] are members of the proposed estimator. We have also shown that the suggested estimator is more efficient than the estimators of Upadhyaya et al. (2011 Upadhyaya, L.N., Singh, H.P., Chatterjee, S., Yadav, R. (2011). Improved ratio and product exponential type estimators. J. Stat. Theo. Pract. 5 (2): 285–302.[Taylor &; Francis Online] , [Google Scholar]) and Yadav and Kadilar (2013 Yadav, S.K., Kadilar, C. (2013). Improved exponential type ratio estimator of population variance. Revis. Colum. de Estadist. 36(1): 145–152. [Google Scholar]). Numerical illustration is provided in support of the present study.