Extension of two-sided test to multiple treatment trials

In a two-treatment trial, a two-sided test is often used to reach a conclusion, Usually we are interested in doing a two-sided test because of no prior preference between the two treatments and we want a three-decision framework. When a standard control is just as good as the new experimental treatment (which has the same toxicity and cost), then we will accept both treatments. Only when the standard control is clearly worse or better than the new experimental treatment, then we choose only one treatment. In this paper, we extend the concept of a two-sided test to the multiple treatment trial where three or more treatments are involved. The procedure turns out to be a subset selection procedure; however, the theoretical framework and performance requirement are different from the existing subset selection procedures. Two procedures (exclusion or inclusion) are developed here for the case of normal data with equal known variance. If the sample size is large, they can be applied with unknown variance and with the binomial data or survival data with random censoring.     

A New Model of Trend Inflation

This article introduces a new model of trend inflation. In contrast to many earlier approaches, which allow for trend inflation to evolve according to a random walk, ours is a bounded model which ensures that trend inflation is constrained to lie in an interval. The bounds of this interval can either be fixed or estimated from the data. Our model also allows for a time-varying degree of persistence in the transitory component of inflation. In an empirical exercise with CPI inflation, we find the model to work well, yielding more sensible measures of trend inflation and forecasting better than popular alternatives such as the unobserved components stochastic volatility model. This article has supplementary materials online.     

Assessing and Improving the Performance of Nearly Efficient Unit Root Tests in Small Samples

Abstract

The development of unit root tests continues unabated, with many recent contributions using techniques such as generalized least squares (GLS) detrending and recursive detrending to improve the power of the test. In this article, the relation between the seemingly disparate tests is demonstrated by algebraically nesting all of them as ratios of quadratic forms in normal variables. By doing so, and using the exact sampling distribution of the ratio, it is straightforward to compute, examine, and compare the test' critical values and power functions. It is shown that use of GLS detrending parameters other than those recommended in the literature can lead to substantial power improvements. The open and important question regarding the nature of the first observation is addressed. Tests with high power are proposed irrespective of the distribution of the initial observation, which should be of great use in practical applications.     

Proposed best practice for statisticians in the reporting and publication of pharmaceutical industry‐sponsored clinical trials

In this paper we set out what we consider to be a set of best practices for statisticians in the reporting of pharmaceutical industry‐sponsored clinical trials. We make eight recommendations covering: author responsibilities and recognition; publication timing; conflicts of interest; freedom to act; full author access to data; trial registration and independent review. These recommendations are made in the context of the prominent role played by statisticians in the design, conduct, analysis and reporting of pharmaceutical sponsored trials and the perception of the reporting of these trials in the wider community. Copyright © 2010 John Wiley & Sons, Ltd.     

Heaven or Hubris: Reflections on the New ‘New Poverty Agenda’

A new construction on poverty reduction links the Millennium Development Goals, an international consensus on how to reduce poverty, Poverty Reduction Strategy Papers, a new set of instruments for delivering aid, and, underpinning the others, results–based management. This new construction has undoubted strengths. There are also cross–cutting risks, that targets will oversimplify, citizenship will be neglected, trade–offs and conflicts of interest will be obscured, macro–economic policy will be neglected, social sectors will be emphasised at the expense of growth policies, and commitment to partnership will degrade into a form of covert conditionality. These risks are not immutable. A way forward is proposed, with a list of six principles and a set of Dos and Don’ts.     

The Flexibility of Scientific Rhetoric: A Case Study of UFO Researchers

The case of ufology demonstrates that cultural packaging—a sort of once-removed indication of scientific authority—can be key in creating knowledge accepted as scientific. This adds a new dimension to the argument that scientific legitimacy is constructed, not just from scientific methodologies and institutional location, but also of language, culture, rhetoric, and symbols. Fringe researchers can make their cases for legitimacy using a variety of strategies—few of which involve actual research. Outside of the scientific community, scientific-sounding explanations and proclamations of expert statuses hold sway. Ambiguities about what constitutes science can be capitalized upon by groups like the UFO research community that assembles shards of legitimacy using science as a cultural template.     

The extent of children's knowledge of court as estimated by guardians ad litem

‘Knowledge of court’ questionnaires were completed by 35 designated professionals (guardians ad litem) with specific responsibility for children in family proceedings in the civil judicial system within England and Wales who then estimated the percentage of 11‐year old children, in general, which they would expect to provide a ‘full’, ‘partial’ and ‘incorrect’ answer to each question. These estimations were compared with normative data on this questionnaire obtained from actual 11‐year‐olds. This comparison suggests that guardians ad litem tend to overestimate the extent of such children's knowledge, implying that individual children may not be as well prepared for involvement with the legal system as such informed professionals might believe; such a tendency might render it less likely that easily corrected misconceptions and gaps in knowledge be identified and subsequently addressed, thereby failing to minimize the stress (e.g. fear of the unknown) which can often accompany contact with the courts. The possibility that the discrepancy between actual and estimated scores might be, in part, due to a failure in adults to adopt the ‘psychological perspective’ of the child in the unfamiliar world of the adult judicial system is discussed. Although this possibility requires further investigation, making an explicit effort to ‘get into the child's shoes’ is suggested as a potentially valuable and practical first step towards reducing such discrepancies. Copyright © 2000 John Wiley & Sons, Ltd.     

Internationalization and Performance of Firms in China: Moderating Effects of Governance Structure and the Degree of Centralized Control

This study proposes necessary modifications to the existing internationalization–performance relationship to meet the idiosyncrasies of China-specific contexts. We first hypothesize an S-shaped internationalization–performance relationship as the baseline and then investigate the moderating effects of a firm's governance structure and the degree of centralized government control on the relationship between its internationalization and performance. The results, based on a longitudinal sample of manufacturing firms in China for the 2001–2007 period, indicate that (1) the S-shaped internationalization–performance relationship holds for firms in China; (2) the governance structure moderates the internationalization–performance relationship such that increased profitability through internationalization is more likely for modernized firms than for their conventional local counterparts; and (3) the degree of centralized control moderates the internationalization–performance relationship such that increased profitability through internationalization is more likely for firms affiliated with higher level governments than for those affiliated with lower-level governments.