Confidence regions for Pareto parameters from a single and independent samples

[Abstract] Based on a single and on two independent samples, joint confidence regions for parameters of Pareto distributions are proposed with minimum volume properties and without assigning the confidence level to dimensions. In the one-sample case, comparisons are made to former simultaneous confidence sets for Pareto parameters by means of simulation and a real data set. The two-sample case is studied in various set-ups and comprises simultaneous confidence regions for the shape parameters, the scale parameters, and higher-dimensional vectors of these parameters, where common shape and common scale models are also considered.     

Adaptive designs for single‐arm phase II trials in oncology

Clinical phase II trials in oncology are conducted to determine whether the activity of a new anticancer treatment is promising enough to merit further investigation. Two‐stage designs are commonly used for this situation to allow for early termination. Designs proposed in the literature so far have the common drawback that the sample sizes for the two stages have to be specified in the protocol and have to be adhered to strictly during the course of the trial. As a consequence, designs that allow a higher extent of flexibility are desirable. In this article, we propose a new adaptive method that allows an arbitrary modification of the sample size of the second stage using the results of the interim analysis or external information while controlling the type I error rate. If the sample size is not changed during the trial, the proposed design shows very similar characteristics to the optimal two‐stage design proposed by Chang et al. (Biometrics 1987; 43:865–874). However, the new design allows the use of mid‐course information for the planning of the second stage, thus meeting practical requirements when performing clinical phase II trials in oncology. Copyright © 2012 John Wiley & Sons, Ltd.     

Access to and exclusion from housing over time: Refugees' experiences in rural areas

Taking the example of recognized refugees in rural Germany, and following the housing pathways approach, the paper addresses the complex interplay of individual and family-related residential preferences over time as well as structural factors regarding access to housing and associated settlement and integration. Results are from a long-term empirical study that encompassed both refugees’ and local actors’ views. Mechanisms and practices of exclusion that prevent refugees from accessing appropriate private housing are related to the negotiation of residential preferences about where and how to live, as well as to structural aspects such as the pattern of local housing markets, accessibility of infrastructures or the unwillingness of landlords to let to refugees. The paper concludes to highlight the role of place in housing trajectories and the significance of social resources within refugees' practices and local intermediaries' strategies to overcome exclusion and provision of access to rural housing.     

The effect of fast and slow decisions on risk taking

We experimentally compare fast and slow decisions in a series of experiments on financial risk taking in three countries involving over 1700 subjects. To manipulate fast and slow decisions, subjects were randomly allocated to responding within 7 seconds (time pressure) or waiting for at least 7 or 20 seconds (time delay) before responding. To control for different effects of time pressure and time delay on measurement noise, we estimate separate parameters for noise and risk preferences within a random utility framework. We find that time pressure increases risk aversion for gains and risk taking for losses compared to time delay, implying that time pressure increases the reflection effect of Prospect Theory. The results for gains are weaker and less robust than the results for losses. We find no significant difference between time pressure and time delay for loss aversion (tested in only one of the experiments). Time delay also leads to less measurement noise than time pressure and unconstrained decisions, and appears to be an effective way of decreasing noise in experiments.     

When Death Isn't Dead: Implicit Social Rationing during Resuscitative Efforts

In this paper, I address the relationship between social death and clinical-biological death during resuscitative efforts. In Western societies, resuscitative efforts are the medical intervention of choice when sudden death occurs. The widespread use of this technology puts emergency department staff in a difficult gatekeeping position. They are expected to save lives, but, at the same time–when their efforts become futile–to prepare for a dignified death. I show that certain groups of patients are much more likely to be considered socially dead regardless of their clinical viability, while others are less likely to be considered socially dead even when irreversible biological death has set in. The result is an implicit rationing of the lifesaving endeavors based on the social worth of the patient. This rationing annihilates initiatives, such as advance directives, which were instituted to empower patients. Social scientists usually suggest that the solution to the negative effects of rationing is to increase accessibility for all populations; however, resuscitative efforts are a prime example in which less access for all groups–instead of for some–might be preferable. This paper is based on observations of 112 resuscitative efforts during a fourteenth-month period and interviews with 42 health care providers.     

Micro‐Situational Antecedents of Violent Atrocity1

This article presents an analysis of video recordings showing micro‐situational events that preceded the 1995 Srebrenica massacre in which more than 7,000 Bosnian‐Muslim men were killed by troops of the Bosnian Serb Army. The article focuses on the sequential unfolding of micro interactions and emotional dynamics that preceded the atrocity. Micro interactions constitute situational turning points toward, or away from, atrocities. Even if there are preplanned plots or macro‐structural background conditions that lead particular persons to be motivated to commit violence, a micro‐situational, emotional momentum is needed for atrocities to occur. The article brings together the analysis of video material of violent situations with Ekman’s research tools for emotional cues and Collins’s micro‐sociological theory of violence.     

The Steiner cycle and path cover problem on interval graphs

The Steiner path problem is a common generalization of the Steiner tree and the Hamiltonian path problem, in which we have to decide if for a given graph there exists a path visiting a fixed set of terminals. In the Steiner cycle problem we look for a cycle visiting all terminals instead of a path. The Steiner path cover problem is an optimization variant of the Steiner path problem generalizing the path cover problem, in which one has to cover all terminals with a minimum number of paths. We study those problems for the special class of interval graphs. We present linear time algorithms for both the Steiner path cover problem and the Steiner cycle problem on interval graphs given as endpoint sorted lists. The main contribution is a lemma showing that backward steps to non-Steiner intervals are never necessary. Furthermore, we show how to integrate this modification to the deferred-query technique of Chang et al. to obtain the linear running times.