Aggregation of Directional Distance Functions and Industrial Efficiency

Three main objectives are pursued in this paper. First, we intend to analyze the aggregation problem of directional distance functions from a constructive viewpoint. We provide necessary and sufficient conditions concerning the structural properties of the production technology and of the nature of groups of firms. Indeed, exact additive aggregation holds for a linear technology and for a direction solely defined in the output space. Second, since these conditions are somewhat restrictive, we are interested in providing a measure for the aggregation bias through the relationship between industrial and structural technical efficiency. Finally, we show that this aggregation bias is a lower bound for industrial allocative efficiency.     

Continuous choice functions and the strong axiom of revealed preference

Summary In this note, it is shown that a result due to Uzawa showing that the weak axiom of revealed preference together with a regularity condition implies the strong axiom of revealed preference can be derived from the regularity conditionalone, if the choice function is continuous in prices and in income. The observation that the weak axiom of revealed preference is not needed suggests that this regularity condition is remarkably strong. The main result of the paper is quite general in the sense that the only additional assumption on the choice function is that the whole budget be spent.I thank Charles Blackorby for his comments on an earlier version.     

Karoushi: Stress-death and the meaning of work

The present article is concerned with some of the human factors involved when overtime and overwork become part of the regular and accepted pattern of work, with sometimes tragic results. While the economic miracle of Japan can be much admired, it has not been without human cost. Only recently, national and global attention is being focused on a new and deadly phenomenon in Japan:Karoushi, which the Japanese define as death from overwork, and which I choose to re-define as stress-death related to feelings of helplessness.It is my tentative hypothesis thatkaroushi is not directly caused by overwork, as popularly assumed. Rather, I believe that overwork is only one factor, and that stress-death is actually caused by the cumulative, long-range effects of working in a situation where one feels trapped and powerless to effect any change for the better, which in turn leads to attitudes of hopelessness — attitudes which are exacerbated, rather than ameliorated, by environmental and managerial factors.Dr. Walter Tubbs received his Ph.D. in Neuropsychology and Philosophy after doing work at Stanford and Drew Universities. After involvement in brain research at Stanford, he practiced stress-management counseling and biofeedback training at Loma Linda University, and taught for 13 years at the University of Redlands in California. He has been in Japan for 11 years as a Senior Researcher.     

Patent-based inventor profiles as a basis for human resource decisions in research and development

Profiles of inventors' technological competence are a valuable source of information for decision-making in research and development (R&D) management, e.g. concerning inventor assessment, human resource development and R&D team-building. In the following exposition, a new method of inventor profiling will be put forward, which is based in particular on semantic patent analysis and multidimensional scaling. First, in the course of semantic patent analysis, specialized software, equipped with a natural language processor, reads the patent text transferring the contents into a subject–action–object–format (SAO). The extracted SAO structures are then used to create similarity matrices for patents or patent sets, respectively, according to a specific similarity value. Subsequently, an inventor competence map can be produced by means of multidimensional scaling.
The benefits of this method for R&D-related issues in human resource management will be illustrated by the example of a German mechanical engineering company. Two distinct types of profiles were generated and tested: (i) the profile of a single key inventor and (ii) a profile of key inventor sets. The single key inventor profile gives information on the range of competence, i.e. the homogeneity or heterogeneity of a certain inventor's competences, providing far more detailed insights than resorting to bibliographic data like international patent classification (IPC) classes or citations, whereas the latter kind of profile establishes the position of a certain key inventor in relation to others, helping to highlight specific groups of inventors and their domains. These results are clearly apt to support human resource management.     

Substitution between leisure activities: a quasi-natural experiment using sports viewing and cinema attendance

The allocation of time between leisure activities and work has been extensively analysed in academic literature. However, leisure time is limited and there may not be sufficient time to enjoy all the leisure activities desired. Hence, this article considers the allocation of time between substitute leisure activities. International football tournaments provide an opportunity to consider consumers’ preferences for watching football and films in a quasi-natural experimental setting. A trade-off between these leisure activities is identified using a difference-in-difference methodology. Using an original, four-country data set, a large and robust negative effect of mega sports events on cinema admissions is identified.