The k-sample problem in a multi-state model and testing transition probability matrices

The choice of multi-state models is natural in analysis of survival data, e.g., when the subjects in a study pass through different states like ‘healthy’, ‘in a state of remission’, ‘relapse’ or ‘dead’ in a health related quality of life study. Competing risks is another common instance of the use of multi-state models. Statistical inference for such event history data can be carried out by assuming a stochastic process model. Under such a setting, comparison of the event history data generated by two different treatments calls for testing equality of the corresponding transition probability matrices. The present paper proposes solution to this class of problems by assuming a non-homogeneous Markov process to describe the transitions among the health states. A class of test statistics are derived for comparison of \(k\) treatments by using a ‘weight process’. This class, in particular, yields generalisations of the log-rank, Gehan, Peto–Peto and Harrington–Fleming tests. For an intrinsic comparison of the treatments, the ‘leave-one-out’ jackknife method is employed for identifying influential observations. The proposed methods are then used to develop the Kolmogorov–Smirnov type supremum tests corresponding to the various extended tests. To demonstrate the usefulness of the test procedures developed, a simulation study was carried out and an application to the Trial V data provided by International Breast Cancer Study Group is discussed.     

Exploring the association between board and organizational performance in nonprofit organizations

Note: This study investigated six dimensions of effective board performance, as suggested by Chait, Holland, and Taylor (1991), in relation to three theoretical explanations (agency theory, resource dependency theory, and group/decision process theory) of how board governance activities potentially influence organizational performance. Survey research findings revealed that strategic contributions from the board are more robust in organizations with higher financial performance. In addition, organizations that are judged to be higher performing also reported having high‐performing boards across all dimensions. In particular, the interpersonal dimension provided a unique explanation of judgments of organizational performance.     

Gender dysphoric/gender variant (GD/GV) children and adolescents: summarizing what we know and what we have yet to learn

The optimal approach to treating minors with gender dysphoria/gender variance (GD/GV) is much more controversial than treating these phenomena in adults. This is because children have limited capacity to participate in decision making regarding their own treatment, and even adolescents have no legal ability to provide informed consent. Minors must, therefore, depend on parents or other caregivers to make treatment decisions on their behalf, including those that will influence the course of their lives in the long term. Presently, the highest level of evidence available for selecting among the various approaches to treatment is best characterized as "expert opinion." Yet, opinions vary widely among experts and are influenced by theoretical orientation and assumptions and beliefs regarding the origins of gender identity, as well as its perceived malleability at particular stages of development. This article outlines some of the more salient points raised by the clinicians who treat GD/GV and their discussants. This article summarizes what the editors believe is known and what has yet to be learned about minors with GD/GV, their families, their treatment, and their surrounding cultures.     

Using Malmquist Indexes to measure changes in the productivity and efficiency of US accounting firms before and after the Sarbanes–Oxley Act

There have been many criticisms of the Sarbanes–Oxley (SOX) Act passed in July of 2002 to correct business accountability and performance practices. The act has a major emphasis on accounting and its practices. This paper attempts a response to these criticisms by investigating changes in productive efficiency for 62 of the largest US public accounting firms between the periods (2000–2001) and (2003–2004)—the periods before and after enactment of SOX in July of 2002. DEA is used to calculate Malmquist indexes of productivity and efficiency changes. This index is used because it can distinguish between changes in technical efficiency, which limit the possibilities, and changes in the performance efficiencies for each firm. Contrary to many of the criticisms, results indicate that accounting firms have exhibited significant post SOX growth in productive efficiency which is better than pre-SOX performances.     

Using expected values to simplify decision making under uncertainty

A simulation study examines the impact of a simplification strategy that replaces distributional attribute evaluations with their expected values and uses those expectations in an additive value model. Several alternate simplified forms and approximation approaches are investigated, with results showing that in general the simplified models are able to provide acceptable performance that is fairly robust to a variety of internal and external environmental changes, including changes to the distributional forms of the attribute evaluations, errors in the assessment of the expected values, and problem size. Certain of the simplified models are shown to be highly sensitive to the form of the underlying preference functions, and in particular to extreme non-linearity in these preferences.     

A Note on Air‐Cargo Capacity Contracts

Carriers (airlines) use medium‐term contracts to allot bulk cargo capacity to forwarders who deliver consolidated loads for each flight in the contractual period (season). Carriers also sell capacity to direct‐ship customers on each flight. We study capacity contracts between a carrier and a forwarder when certain parameters such as the forwarder's demand, operating cost to the carrier, margin, and reservation profit are its private information. We propose contracts in which the forwarder pays a lump sum in exchange for a guaranteed capacity allotment and receives a refund for each unit of unused capacity according to a pre‐announced refund rate. We obtain an upper bound on the informational rent paid by the carrier for a menu of arbitrary allotments and identify conditions under which it can eliminate the informational rent and induce the forwarder to choose the overall optimal capacity allotment (i.e., one that maximizes the combined profits of the carrier and the forwarder).     

The Surgical Scheduling Problem: Current Research and Future Opportunities

This paper reviews the general problem of surgical scheduling. We organize the literature based on the time frame or planning horizon of the schedule into six categories: capacity planning, process reengineering/redesign, the surgical services portfolio, procedure duration estimation, schedule construction, and schedule execution, monitoring, and control. We survey past work and suggest topics for potential future research in each of those areas.     

美国极权主义心理解析——以《裸者与死者》为例

《裸者与死者》对美国极权主义的揭露与批判是批评界研究的焦点。新精神分析学派认为,极权主义和法西斯主义拥有同样的心理基础"权威主义性格",其运行的心理机制取决于施虐-受虐冲动,为剖析小说中复杂、矛盾的集体性格特征,揭示美国军队"机器人"的产生缘由提供了理论依据。以《裸者与死者》为例对极权主义的心理解析有助于挖掘现代战争与杀戮的深层根源,对当下有警示作用。     

Construct Validity of the Emotion Matching Task: Preliminary Evidence for Convergent and Criterion Validity of a New Emotion Knowledge Measure for Young Children

Current emotion knowledge (EK) measures examine only one component of the multifaceted construct. We examined the reliability and the construct validity of a new measure of EK, the emotion matching task (EMT). The EMT consists of four parts which measure the components of receptive EK, expressive EK, emotion situation knowledge, and emotion expression matching. First, we compared the EMT and its parts to two widely used EK measures—the Kusche emotional inventory (KEI) and Denham's affective knowledge test (AKT, 1986) in order to establish convergent validity. The EMT and its four parts were strongly correlated with both measures of EK. Regression analyses revealed moderate to strong predictive validity for EMT. Compared with KEI and AKT, the EMT was a more robust predictor of teacher-rated emotion regulation and parent reported effortful control. Compared with KEI and AKT, the EMT correlated similarly with verbal ability and age.     

Offshoring and Cross‐Border Interorganizational Relationships: A Justice Model*

In this article, we develop an interorganizational justice model to explain cross‐border interorganizational relationships. The model contends that cultural distance (construed as the cultural differences between offshoring partners) would influence behavioral uncertainty and the boundary spanners' perceptions of justice. Specifically, the model predicts that high levels of behavioral uncertainty are likely to reduce relational commitment, whereas low levels of behavioral uncertainty are likely to enhance relational commitment. However, boundary spanners' perceptions of distributive, procedural, and interactional justice would mitigate the negative impact of behavioral uncertainty on relational commitment. The model also predicts that culturally similar boundary spanners would be more likely to share similar perceptions of distributive, procedural, and interactional justice than culturally dissimilar boundary spanners. This model has implications for further theoretical discussion and empirical research as well as management practice. Managers could use the interorganizational justice model to assess shared perceptions of justice among boundary spanners and develop transcultural justice competencies.