Vertrauen bei Internet-Auktionen

The text replies to the article “Trust and Reputation in Internet-Auctions” (KZfSS, Vol. 54, No. 4, pp. 674–693) by Diekmann and Wyder. In principle the authors’ consideration regarding a premium for reputation for trustworthy participants in internet auctions seems to be attractive. However, we object to the lacking definitions of the categories of trust and reputation as well as to the problematic design of their central indicator (reputation). With regard to their interpretation we criticize the missing consideration of qualitative — especially negative — statements in the public rating systems, underestimating the relevance of “critical incidents” to fragile trust relations on the internet. Finally we remark that Diekmann and Wyder misjudge the founding, cultivating and modifying activities (including imposing sanctions) of the platform owner towards this institution regulating the market.     

A 1,408 km bicycle tour with prostate cancer patients—results of a pilot study

Negative psychological and physical effects of prostate cancer and its medical treatment may persist many years after diagnosis. The influence of a long cycling tour on rehabilitative or health-related effects with prostate cancer patients has not yet been studied. In practice, physicians and therapists rarely recommend cycling to prostate cancer. In May 2010, eight prostate cancer patients rode their bikes for over 1,408 km from Cologne to Marseille within 5 weeks. Endurance test, blood examinations (prostate-specific antigen (PSA), total testosterone, interleukin-6, oxidative stress, and antioxidant capacity) and quality of life questionnaires were completed before and after the tour. All eight subjects reached Marseille. Significant improvements could be observed in physical performance and certain quality of life scores (p?=?0.008), as well as a reduction of total testosterone (p?=?0.19). PSA levels did not change. This pilot study suggests that long bicycle tours with prostate cancer patients are feasible. Due to the missing control group and the small sample size, the results of this pilot study are limited.     

Housing Conditions and Risk: Reporting on a European Study of Housing Quality and Risk of Accidents for Older People

The declining capacities in older people often lead to limitations in activities of daily living and a simultaneous rising demand for care services. Many of these limitations in daily activities are to a varying degree caused, enhanced or facilitated by disadvantageous housing and environmental conditions. Home modifications have been credited as an important part of the solution, allowing for an extended and safer use of the home. In order to examine this issue in more detail, this paper provides empirical evidence on the type and extent of risks associated with accidents around the home. It reports on findings from a European case study on the difficulties using the home and risks of accidents which may lead to injury. It is argued that healthy housing conditions for older persons are important to maximize the supportive capacity of one's home, to stimulate an active and healthy lifestyle, and to avoid unnecessary institutionalization.     

Media orientation of German university decision makers and the executive influence of public relations

This study investigated the executive influence of public relations managers in the German higher education system. The study is based on a whole-population survey of German university decision makers (N = 1619). It provides evidence that the mediatization of German higher education offers an important opportunity for the empowerment of university PR departments. They can benefit from the New Public Management reforms in recent years as power shifts to management-oriented administrators and the public image of universities turns into a competitive asset. Nevertheless, an indispensable precondition for PR departments’ organizational advancement resides in professionalization. PR workers need to claim a status of expert boundary spanners between their universities and the public stakeholders.     

Does signaling childcare support on job applications reduce the motherhood penalty?

Review of Economics of the Household - There is substantial evidence that due to perceived childcare obligations, mothers are disadvantaged in labor markets. To what extent can childcare support...     

Maximum-likelihood estimation of the random-clumped multinomial model as a prototype problem for large-scale statistical computing

Numerical methods are needed to obtain maximum-likelihood estimates (MLEs) in many problems. Computation time can be an issue for some likelihoods even with modern computing power. We consider one such problem where the assumed model is a random-clumped multinomial distribution. We compute MLEs for this model in parallel using the Toolkit for Advanced Optimization software library. The computations are performed on a distributed-memory cluster with low latency interconnect. We demonstrate that for larger problems, scaling the number of processes improves wall clock time significantly. An illustrative example shows how parallel MLE computation can be useful in a large data analysis. Our experience with a direct numerical approach indicates that more substantial gains may be obtained by making use of the specific structure of the random-clumped model.     

Workload Control and Order Release: A Lean Solution for Make‐to‐Order Companies

Protecting throughput from variance is the key to achieving lean. Workload control (WLC) accomplishes this in complex make‐to‐order job shops by controlling lead times, capacity, and work‐in‐process (WIP). However, the concept has been dismissed by many authors who believe its order release mechanism reduces the effectiveness of shop floor dispatching and increases work center idleness, thereby also increasing job tardiness results. We show that these problems have been overcome. A WLC order release method known as “LUMS OR” (Lancaster University Management School order release) combines continuous with periodic release, allowing the release of work to be triggered between periodic releases if a work center is starving. This paper refines the method based on the literature (creating “LUMS COR” [Lancaster University Management School corrected order release]) before comparing its performance against the best‐performing purely periodic and continuous release rules across a range of flow directions, from the pure job shop to the general flow shop. Results demonstrate that LUMS COR and the continuous WLC release methods consistently outperform purely periodic release and Constant WIP. LUMS COR is considered the best solution in practice due to its excellent performance and ease of implementation. Findings have significant implications for research and practice: throughput times and job tardiness results can be improved simultaneously and order release and dispatching rules can complement each other. Thus, WLC represents an effective means of implementing lean principles in a make‐to‐order context.