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.     

From the 30s to the 60s: The folk music revival in the United States

Conclusion Woody Guthrie's ashes were spread by the wind over the water from a Coney Island, New York pier a few days after he died on Oct. 3, 1967. His wife and children, including his 19-year-old son Arlo, were present as America's greatest folksinger was laid to rest. One of the last things Woody heard before he died was Arlo's recorded voice singing the draft-dodging tale of Alice's restaurant. He must have sensed that the spirit had been passed on. Woody Guthrie died just as the second great wave of popular interest in American folk music was coming to an end. Alice's Restaurant was in many ways one of its last echoes. The symbolism could not have been more poignant. At the center of the first folk revival, Woody Guthrie was a vital source of inspiration for the second.The new generation of singer-songwriters who marked the second wave was largely composed of those with at least some contact with the new mass higher education and those multi-versities that were built to dispense it. They were neither members of a déclassé elite, as could be said of Charles and Pete Seeger and John and Alan Lomax, nor were they authentic folk singers, like Woody Guthrie. Nor could they be. By the 1960s, the conditions that had created the possibility for the first wave of the movement had been irretrievably altered. After the Second World War, with a postwar economic expansion and population explosion under way, America was a different place. Besides, the first folk revival had already claimed authenticity as its own. For the most part, if there was any aspiration toward authenticity amongst the topical singer-songwriters (those in New York City in any case), it was to be as close a copy of the first generation, Guthrie and Seeger, as possible. Purism was the second wave's answer to the authenticity of the first.Being part of an expanding generation of white, college-educated youths affected the form and content of the music that characterized the second wave. The most obvious aspect of this was the arena of performance and the audience who filled it. Gone were the union halls, the singing in working-class bars and beerhalls and at Party functions, all of which had characterized the first wave. These were replaced first by coffee shops and small clubs, either in Greenwich Village or those surrounding college campuses. The forays into the South in support of the civil-rights movement were for the most part short-lived and highly symbolic, not to say self-serving. The real mass audience arrived with the antiwar activity and was largely university centered.It was also this audience that filled the auditoriums and concert halls for the more obviously commercial performances by the singer-songwriters of the second wave. This overlapping public provided the grounds for a new mass market in folk music. Peter, Paul, and Mary, who sang in front of many mass demonstrations in protest against the war in Vietnam or in support of civil rights, were, although they saw themselves as carrying on in the spirit of the Weavers, an entirely commercial creation. In the article from the East Village Other cited above, written just after the first big concert in America against the war in Vietnam, Izzy Young angrily notes that everybody was a part of it except the people managed by Albert Grossman - Peter, Paul and Mary, and Bob Dylan. When the war in Vietnam became popular, three years later, Peter, Paul and Mary flew down to Washington, D.C. to take their place in front of the cameras.Commercial rationality was much more a factor in defining the second folk revival than the first. The possibilities were greater and the structure of the music industry was different. With a new mass market still in the process of formation and thus unspecified in terms of taste, the larger record companies could afford to take a liberal attitude and to include under their label, all the revolutionaries, as Columbia Records proudly announced in its contemporary advertising. Commercial possibilities thus were more important in shaping the musical form and content of second folk revival than politics, which were so central to the first. As opposed to the old left, the new left was a loosely organized contingent of organizations and groups with little coordination between them. In fact, many if not most of the organizations were ad hoc committees formed for a specific strike or demonstration. No one group was thus in a position to exert ideological hegemony. Following from this, at least during the period under discussion, there was little political dogmatism to be found. With no powerful organization to impose it, there was no clear political line to defend and thus to sing about. Even the notion of the people, so central to the first folk revival, was relatively absent in the second. Who were the people addressed? Certainly not the working class or even the common man. I am just a student, Sir, I only want to learn, sang Phil Ochs.During the second folk revival, the people had become the silent majority, the province of the conservative right. Neither in music nor in politics did the new left make many attempts to reach the common man in the street. The people had been massified, according to new left theory, and in the new one-dimensional mass society the grounds of political and social identity were always shifting. Besides, country music had already established itself as the musical genre of the rural, southern, western and white, common man. From a commercial point of view, there was little need to look for authenticity or the people; the market was sufficiently large and getting larger as more and more young people entered the institutions of higher education. Politically, this was not a serious problem either, as long as the aim was not revolution as it had been for the old left. It was sufficient, then, to address the masses of youngsters gathering together at institutions of higher education. If there was a revolution at foot, this was it.While the first wave practically had to invent folk music, the second could draw on the reservoir of public culture that to a large extent resulted from this invention. The networks and institutional support provided by the old left and the personal authority of a figure like Alan Lomax made possible the imposition of rather strict criteria for determining in what exactly folk music consisted. Neither networks nor gatekeepers were so determinate to the second wave. With the folksong and folksinger already invented, the new generation could pick and choose from a rather wide range of options. In addition, by the time the new left and the topical-song movement achieved at least a semblance of cohesion, folk music was already institutionally supported by radical entrepreneurs like Izzy Young and the more commercial recording industry. There were, thus, strong institutional bases for folk music outside of politics. Politics, in other words, was not the only game in town. But neither was commerce. The civil-rights movement and the new social movements that developed out of it opened for a short period a space, a public arena, in which the idea of folk music could be reinvented anew. Within this space the traditions constituted during the first wave of folk revival were experimented with and modified in light of the new social and historical context. America was not the same place in the 1960s as it had been in the 1930s and neither could its folk music be. The actors, the setting, and the songs were all different, yet still the same.In attempting to account for both this continuity and change in the two waves of folk revival we have drawn from both the cognitive approach to the study of social movements, which calls attention to the creative role of social-movement actors in the production of knowledge, and the production of culture perspective, which highlights the effects of institutional arrangements in the production of cultural goods. From the former, we have focused on the changing character of movement intellectuals, those to whom Ralph Rinzler in the epigraph that begins this article gave special place; from the latter, we have noted how, among other things, the changing nature of the recording industry helped recast the folk music revival. We hope that the foregoing has demonstrated that in combining these approaches, as well as areas of research interest, we have uncovered aspects of the folk revival others may have missed.     

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。     

＂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.