Efficient Tests Under a Weak Convergence Assumption

The asymptotic validity of tests is usually established by making appropriate primitive assumptions, which imply the weak convergence of a specific function of the data, and an appeal to the continuous mapping theorem. This paper, instead, takes the weak convergence of some function of the data to a limiting random element as the starting point and studies efficiency in the class of tests that remain asymptotically valid for all models that induce the same weak limit. It is found that efficient tests in this class are simply given by efficient tests in the limiting problem—that is, with the limiting random element assumed observed—evaluated at sample analogues. Efficient tests in the limiting problem are usually straightforward to derive, even in nonstandard testing problems. What is more, their evaluation at sample analogues typically yields tests that coincide with suitably robustified versions of optimal tests in canonical parametric versions of the model. This paper thus establishes an alternative and broader sense of asymptotic efficiency for many previously derived tests in econometrics, such as tests for unit roots, parameter stability tests, and tests about regression coefficients under weak instruments.     

Risk factors for femicide-suicide in abusive relationships: results from a multisite case control study

The killing of women by men who then take their own lives (femicide-suicide) is the most common form of homicide-suicide. This study identified femicide-suicide risk factors in an 11-city case-control study of femicide in the United States. Perpetrator, victim, relationship, and incident characteristics were analyzed for femicide-suicide cases (n = 67) and controls (n = 356, women living in the community with nonfatal physical abuse) using logistic regression modeling. Two risk factors emerged that were unique to femicide-suicides cases compared to overall femicide risk analyses: prior perpetrator suicide threats and victims having ever been married to the perpetrator.     

HAC Corrections for Strongly Autocorrelated Time Series

Applied work routinely relies on heteroscedasticity and autocorrelation consistent (HAC) standard errors when conducting inference in a time series setting. As is well known, however, these corrections perform poorly in small samples under pronounced autocorrelations. In this article, I first provide a review of popular methods to clarify the reasons for this failure. I then derive inference that remains valid under a specific form of strong dependence. In particular, I assume that the long-run properties can be approximated by a stationary Gaussian AR(1) model, with coefficient arbitrarily close to one. In this setting, I derive tests that come close to maximizing a weighted average power criterion. Small sample simulations show these tests to perform well, also in a regression context.     

External commercialization of knowledge: Review and research agenda

Companies increasingly make use of external knowledge exploitation, i.e. the commercialization of knowledge assets, although they often perceive considerable difficulties in managing external commercialization tasks. These difficulties are partly due to the imperfections in the markets for knowledge, which may be mastered by adequate management, as examples of various well-known companies show. In combination, these facts point to the need for research into external knowledge exploitation. A thorough analysis of past research confirms this need and shows that the existing literature is highly fragmented. By integrating the main findings of the different research streams, a detailed overview of the literature on external knowledge exploitation is established. The key characteristics of externally leveraging knowledge assets are presented, and a research agenda is set up.     

Issues in the assessment of non-inferiority: perspectives drawn from case studies

Superiority claims for improved efficacy are the backbone of clinical development of new therapies. However, not every new therapy in development allows for such a claim. Some therapies per se do not try to improve efficacy further but concentrate on important aspects in safety or convenience. Such improvements can be equally important to patients, and development strategies should be available for such compounds. A three-arm design with placebo, active control and experimental treatment may be viewed as the golden standard for such compounds; however, it may be difficult if not impossible to add a placebo arm in certain diseases. In such situations, non-inferiority designs are the only development option left. This paper will highlight some of the key issues with such designs in practice and will report experience from two studies from different therapeutic areas intended for regulatory submission.     

Process matters – How strategic decision-making process characteristics impact capital allocation efficiency

We employ strategic decision-making process theory to study the internal capital markets of firms and argue that varying allocation efficiency can result from the configuration of the capital allocation decision-making process. Learning from earlier research on firms' portfolio allocations, we also develop assumptions on interaction effects with firm-level unrelated diversification and environmental dynamics. We test our hypotheses with structural equation modeling on an international sample of large multi-business firms. Our results suggest that process formalization and analytical comprehensiveness have a positive influence on the efficiency of allocation decisions. Another key result is that unrelated diversified portfolios positively moderate the influence of analytical comprehensiveness and formalization, while dynamic environments negatively impact the influence of formal processes but reward managerial involvement.     

Resource utilization as an internal driver of alliance portfolio evolution: The Qatar Airways case (1993–2010)

This article aims to understand the role played by resource utilization levels as a driver of alliance portfolio evolution over time. Based on our theoretical framework and on a case study of Qatar Airways (199.3–2010), we develop insights into the micro-dynamics of resource structuring in firms that possess an alliance portfolio. Our research shows that firms can create either their own or network resources with different deployment modes according to their resource utilization levels to remain profitable. We also emphasize that optimized resource utilization is a key driver of resource-structuring efforts in firms. Finally, we show that based on the focal firm's life cycle phase, the level of resource utilization changes and leads to various resource-structuring mechanisms that can be observed at the alliance portfolio level.     

An ‘unholy alliance’ of existential proportions: Negotiating discourses with men's experiences of cancer and aging

Little is understood about how experiencing cancer and aging together can disrupt people's socio-personal worlds and lead to existential questions about identity, life ambiguity, and death. Toward this end, we interpreted the metaphors that three aging men with cancer used in a focus group to describe their existential concerns. We also considered how two dominant cultural discourses around cancer and aging, generally referred to as discourses of “progress” and “decline”, figured into the participants' meanings. Finally, we compared the men's attitudes toward cancer and aging to dominant ideas about how men respond to these life events. Through interpretative phenomenological analysis, informed by critical phenomenology, we came to three conclusions. First, the men's interpretations of cancer and aging shared similar existential themes of tragedy and transcendence. Second, these existential concerns were informed by dominant discourses of cancer and aging, in that they followed the culturally constructed trajectories of decline and progress, respectively. The men's metaphors point to a negotiation of these two discourses. A third and related point is that the men predominantly contradicted gendered assumptions about dealing with life adversity but in some ways repeated them. This research indicates that people interpret cancer and aging in somewhat shared ways, via dominant cultural discourses, but also in individual ways depending on personal life histories. As discourses and life histories seem to influence how people make sense of aging life with cancer, it may be useful to be aware of these contexts when providing psycho-social care to aging cancer patients.     

Is There a Stabilizing Selection Around Average Fertility in Modern Human Populations?

Possibly the greatest challenge for an evolutionary explanation of demographic transition is the fact that fertility levels universally start to fall first among the well‐to‐do, well‐educated, healthy classes, which can be explained only by some voluntary or at least adaptive action. The problem of how restraints on fertility could have evolved by natural selection has been tackled with group selection models as well as with stabilizing selection models. The latter model, which is critically discussed in this article, posits that some intermediate (rather than maximal) level of fertility is optimal for long‐term reproductive success. Tests of stabilizing selection in human populations are rare, their results inconclusive. Here four sets of data are analyzed: they are samples drawn from the 'class of 1950 of the US Military Academy at West Point (cohorts 1923–29), retired US noncommissioned officers (cohorts 1913–37), and western German and eastern German physicians (cohorts 1930–35), all containing fertility data over two generations, and from European royalty (cohorts 1790–1939) containing fertility data over four generations. Deterministic as well as stochastic fitness measures are used. It is found that maximal, not average, fertility in the first generation leads to maximal long‐term reproductive success. Also against prediction, no decreasing marginal fitness gains by increasing fertility can be observed. The findings leave little space for considering stabilizing selection as a plausible mechanism explaining the course of demographic transition but indicate instead that biological evolution today is as fast and vigorous as ever in human history. Even in large populations, all people living today may be the descendants of just some few percents—a much smaller proportion than generally believed— of the people living some generations ago.