Do bettors prefer long shots because they are risk-lovers,or are they just overconfident?

This study examines whether bettors' risk preferences or overconfidence in choosing winners better explains their well documented preference for low-probability wagers. Although previous studies using racetrack data often suggest that risk-loving behavior explains long-shot preference, such data cannot distinguish between the alternative explanations. We use football betting data to make the comparison and find that overconfidence more closely fits the data. This result complements evidence of overconfidence from behavioral studies as well as stock-market models of overconfident noise traders.     

工业革命:过去与未来

通过全球经济增长的跨世纪比较,作者洞察出18世纪末开始的工业革命之后的经济增长与先前经济增长之根本不同在于工业世界是以人口总量相对于产出总量的增长率呈现稳定下降态势和广大普通民众生活水准的普遍提高为典型特征。进一步的分析表明,以马尔萨斯(Malthus)的人口理论为代表的传统经济增长理论可以成功解释传统农业社会里各国人均收入大致相等且基本上不随时间的变化而改变,而以贝克尔(Becker)的人力资本积累理论为代表的现代经济增长理论则可以成功解释现代工业社会中全球人均收入的持续大幅度成长、跨国人均收入的巨大不平等和人均收入跨国分布的动态变化。最后,作者指出随着仍然处在进行中的工业革命向全球各个角落扩散,世界人均收入整体上将不断提高,而解决全球低收入人群生活水准的最佳途径是不断地增加世界产出总量,而非重新分配现有的世界总产出。     

An Improved Method on Wilcoxon Rank Sum Test for Gene Selection from Microarray Experiments

Selecting a small subset out of the thousands of genes in microarray data is important for accurate classification of phenotypes. In this paper, we propose a flexible rank-based nonparametric procedure for gene selection from microarray data. In the method we propose a statistic for testing whether area under receiver operating characteristic curve (AUC) for each gene is equal to 0.5 allowing different variance for each gene. The contribution to this “single gene” statistic is the studentization of the empirical AUC, which takes into account the variances associated with each gene in the experiment. Delong et al. proposed a nonparametric procedure for calculating a consistent variance estimator of the AUC. We use their variance estimation technique to get a test statistic, and we focus on the primary step in the gene selection process, namely, the ranking of genes with respect to a statistical measure of differential expression. Two real datasets are analyzed to illustrate the methods and a simulation study is carried out to assess the relative performance of different statistical gene ranking measures. The work includes how to use the variance information to produce a list of significant targets and assess differential gene expressions under two conditions. The proposed method does not involve complicated formulas and does not require advanced programming skills. We conclude that the proposed methods offer useful analytical tools for identifying differentially expressed genes for further biological and clinical analysis.     

Some restrictions on the use of corner method hypothesis tests

Beguin et al (1980) introduced the Corner Method as a tool for identifying the order (p,q) of an ARMA proc.ess. In addition they derived approximate hypothesis tests,based on asymptotic theory, to aid in the identification. We show that there are restrictions implicit in the use of these tests which, if violated,could yield spurious results.     

The Effects of a Healthy Families Home Visitation Program on Rapid and Teen Repeat Births

The prevention of Rapid Repeat Births (RRBs) and Teen Repeat Births (TRBs) is an important indicator of the effectiveness of home visitation programs that serve mothers who are at-risk for child maltreatment. This study examined the effects on RRBs and TRBs of a rural/small town home visitation program based on the Healthy Families America (HFA) model. The participants in this study were referred between 1999 and 2007 and included a Treatment Group of 140 at-risk mothers who met minimum engagement criteria and a Comparison Group of 241 at-risk mothers who were referred for services but not enrolled due to limits on program capacity. In addition, county-wide TRB data was used as the basis for a static group comparison. With regard to RRBs, the rates for the Treatment (18%) and Comparison (30%) groups were compared using a Chi-Square test of homogeneity. The null hypothesis that there would be no difference between the rates for the two groups was rejected at the .05 level. Similarly, with regard to TRBs, the null hypothesis that there would be no difference between the rates for the Treatment (9%) and Comparison (27%) groups was rejected at that .01 level. Furthermore, using a Chi-Square test of independence, this investigation tested the null hypothesis that the rates for the two groups would not differ from the county-wide rate (24%). This hypothesis was also rejected at the .01 level. Overall, these results of this inquiry support the conclusion that participants in a rigorously implemented HFA program show significantly lower rates of RRB and TRB when compared to a comparable group of at-risk nonparticipants. They also appear to have a significantly lower incidence of TRB than teen mothers in the general population.     

The Biosociology of Solidarity

For well over a century, sociologists have directed considerable attention to understanding and explaining the processes that produce social solidarity – the feeling of interpersonal connectedness that binds members of society together. Despite the centrality of solidarity to sociological thought, many sociologists remain unaware of the biosocial processes and mechanisms that create and sustain it. We espouse a biosociological viewpoint, which illuminates solidarity as a complex and fascinating interplay between biological and social elements. In this paper we discuss three important advances within the field of neuroscience that point to exciting new avenues of research for sociologists: (i) the discovery of mirror neurons, (ii) developments in the understanding of brain plasticity, and (iii) increased appreciation of the role of non‐conscious processes in social interaction. Additionally, we discuss ongoing basic and applied research to demonstrate how sociologists can capitalize on recent scientific developments to advance their own research agendas. VIDEO ABSTRACT ‐ http://www.youtube.com/watch?v=Is9de_ajheM&hd=1