Refined Inference on Long Memory in Realized Volatility

There is an emerging consensus in empirical finance that realized volatility series typically display long range dependence with a memory parameter (d) around 0.4 (Andersen et al., 2001; Martens et al., 2004). The present article provides some illustrative analysis of how long memory may arise from the accumulative process underlying realized volatility. The article also uses results in Lieberman and Phillips (2004, 2005) to refine statistical inference about d by higher order theory. Standard asymptotic theory has an O(n^-1/2) error rate for error rejection probabilities, and the theory used here refines the approximation to an error rate of o(n^-1/2). The new formula is independent of unknown parameters, is simple to calculate and user-friendly. The method is applied to test whether the reported long memory parameter estimates of Andersen et al. (2001) and Martens et al. (2004) differ significantly from the lower boundary (d = 0.5) of nonstationary long memory, and generally confirms earlier findings.     

Issues in applying recent CPMP ‘Points to Consider’ and FDA guidance documents with biostatistical implications

The International Conference on Harmonisation guideline ‘Statistical Principles for Clinical Trials’ was adopted by the Committee for Proprietary Medicinal Products (CPMP) in March 1998, and consequently is operational in Europe. Since then more detailed guidance on selected topics has been issued by the CPMP in the form of ‘Points to Consider’ documents. The intent of these was to give guidance particularly to non‐statistical reviewers within regulatory authorities, although of course they also provide a good source of information for pharmaceutical industry statisticians. In addition, the Food and Drug Administration has recently issued a draft guideline on data monitoring committees. In November 2002 a one‐day discussion forum was held in London by Statisticians in the Pharmaceutical Industry (PSI). The aim of the meeting was to discuss how statisticians were responding to some of the issues covered in these new guidelines, and to document consensus views where they existed. The forum was attended by industry, academic and regulatory statisticians. This paper outlines the questions raised, resulting discussions and consensus views reached. It is clear from the guidelines and discussions at the workshop that the statistical analysis strategy must be planned during the design phase of a clinical trial and carefully documented. Once the study is complete the analysis strategy should be thoughtfully executed and the findings reported. Copyright © 2003 John Wiley & Sons, Ltd.     

刻意创新

我们大多数人都认同创新是成长的关键途径。问题是如何创新?许多企业依靠突发机遇。也就是说,他们指望某个人提出产品或服务方面的点子,然后从中获利。然而有些时候,企业必须发掘比以往更多的创意,并先于竞争对手将创意化为切实可行的产品与服务。此时,企业便不能再依靠机缘巧合了。我们需要可持续、可重复的创新方法。     

It is risky business: can social capital reduce risk-taking behaviours among disadvantaged youth?

This study addresses the gap in the research for sound multidimensional assessment of social capital and its relationship with risk-taking behaviour among youths living in disadvantaged communities. Social capital and adolescent risk-taking outcomes were studied cross-sectionally in 1371 secondary students living in two disadvantaged communities within Australia. First, a multidimensional measure of social capital was developed and tested using confirmatory factor analysis. Then, the associations between social capital and a range of youth risk-taking behaviours were examined using structural equation modelling across five-year groups (Grades 7–12). With a few exceptions, higher levels of social capital and belongingness within the school and community were generally associated with decreases in smoking, alcohol and drug consumption, and physical violence. Some outcomes were more strongly associated with family and peer social capital, while others associated more with neighbour and community social capital, indicating that attempts to build social capital need to be targeted across the whole community. This study supports the notion that social capital can be measured empirically and is beneficial in alleviating many of the detrimental health outcomes commonly associated with risk-taking behaviours during adolescence.     

Single Parenting in the African American Community: Implications for Public Policy and Practice

The percentage of female-headed African American families has increased significantly since the 1960s. It is now estimated that over half of all African American children will grow up in a female-headed household. This article examines factors related to the formation of these households as well as the challenges associated with these households. Policies and programs that have been implemented to treat these families are examined.     

A Streetcar Named “Derousal”? A Psychophysiological Examination of the Desire–Arousal Distinction in Sexually Functional and Dysfunctional Women

Research indicates that desire and arousal problems are highly interrelated in women. Therefore, hypoactive sexual desire disorder (HSDD) and female sexual arousal disorder (FSAD) were removed from the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), and a new diagnostic category, female sexual interest/arousal disorder (FSIAD), was created to include both arousal and desire difficulties. However, no research has tried to distinguish these problems based on psychosocial-physiological patterns to identify whether unique profiles exist. This study compared psychosocial-physiological patterns in a community sample of 84 women meeting DSM-IV (American Psychiatric Association, 2000 American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th ed., text rev.). Washington, DC: Author.[Crossref] , [Google Scholar]) criteria for HSDD (n = 22), FSAD (n = 18), both disorders (FSAD/HSDD; n = 25), and healthy controls (n = 19). Women completed self-report measures and watched neutral and erotic films while genital arousal (GA) and subjective arousal (SA) were measured. Results indicated that GA increased equally for all groups during the erotic condition, whereas women with HSDD and FSAD/HSDD reported less SA than controls or FSAD women. Women in the clinical groups also showed lower concordance and greater impairment on psychosocial variables as compared to controls, with women with FSAD/HSDD showing lowest functioning. Results have important implications for the classification and treatment of these difficulties.     

＂Inspire Confidence, Stay Relevant＂

(Continued from the last issue)However,I did not feel I had made the right choice and the next time I saw her I apologized.She said to me I had done nothing wrong and said "it’s not your fault teacher,it’s my fault my English is too poor." But I still insisted that I had made a mistake.Yes,I had corrected her,but at what cost? The experience obviously embarrassed her,and her peers by the third time she repeated the word incorrectly had been shaking their heads.She may have left the classroom being able to pronounce the word correctly but what about the damage to her confidence? I thought about it for literally hours.I feared that perhaps next time she might not want to stand up,or shout out the answer in class in case she might be humiliated again.In her mind it was her own incompetence but for me it was my own ignorance.     

STUDENTS WHO CHOOSE AND THE SCHOOLS THEY LEAVE: Examining Participation in Intradistrict Transfers

Data from one urban school district is analyzed to examine equity‐based arguments about school choice as they pertain to intradistrict transfer policies. We specifically examine which factors influence the propensity for parents to participate in choice, and how choice schools differ from the schools that students are zoned to attend. We find that advantaged and disadvantaged parents make similar choices in that they are both likely to choose more affluent schools with better academic records than the schools they are zoned to attend. However, these choices operate in different spheres, as advantaged parents choose the most affluent schools with the best academic records, and disadvantaged parents choose away from the least affluent schools with the worst academic records to schools that are slightly better.