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11.
Thorsten van der Velten Marketing Manager Dr H. Igor Ansoff Distinguished Professor 《Long Range Planning》1998,31(6):879-885
This study analyzes the behavior of top managers in managing their firms' business portfolios. A review of the existing literature provides a conceptual framework for a research design combining quantitative and qualitative techniques. Data were collected through interviews with 35 top managers of well-known German business firms and the findings of this study translated into guidelines for managers. The results suggest that successful top managers should be concerned with the social relationships and management processes within the corporate office, as well as with their use of management concepts in managing the business portfolio. 相似文献
12.
Thiago G. Ramires Niel Hens Gauss M. Cordeiro Gilberto A. Paula 《Journal of applied statistics》2018,45(7):1303-1324
In this paper, we propose a new semiparametric heteroscedastic regression model allowing for positive and negative skewness and bimodal shapes using the B-spline basis for nonlinear effects. The proposed distribution is based on the generalized additive models for location, scale and shape framework in order to model any or all parameters of the distribution using parametric linear and/or nonparametric smooth functions of explanatory variables. We motivate the new model by means of Monte Carlo simulations, thus ignoring the skewness and bimodality of the random errors in semiparametric regression models, which may introduce biases on the parameter estimates and/or on the estimation of the associated variability measures. An iterative estimation process and some diagnostic methods are investigated. Applications to two real data sets are presented and the method is compared to the usual regression methods. 相似文献
13.
A new general class of exponentiated sinh Cauchy regression models for location, scale, and shape parameters is introduced and studied. It may be applied to censored data and used more effectively in survival analysis when compared with the usual models. For censored data, we employ a frequentist analysis for the parameters of the proposed model. Further, for different parameter settings, sample sizes, and censoring percentages, various simulations are performed. The extended regression model is very useful for the analysis of real data and could give more adequate fits than other special regression models. 相似文献
14.
John T. Addison Lutz Bellmann Thorsten Schank Paulino Teixeira 《Journal of Labor Research》2008,29(2):114-137
This paper uses matched employee–employer LIAB data to provide panel estimates of the structure of labor demand in western
Germany, 1993–2002, distinguishing between highly skilled, skilled, and unskilled labor and between the manufacturing and
service sectors. Reflecting current preoccupations, our demand analysis seeks also to accommodate the impact of technology
and trade in addition to wages. The bottom-line interests are to provide elasticities of the demand for unskilled (and other)
labor that should assist in short-run policy design and to identify the extent of skill biases or otherwise in trade and technology.
相似文献
John T. AddisonEmail: |
15.
Osvaldo Loquiha Niel Hens Emilia Martins-Fonteyn Herman Meulemans Edwin Wouters Marleen Temmerman 《Journal of applied statistics》2018,45(10):1781-1798
Two types of bivariate models for categorical response variables are introduced to deal with special categories such as ‘unsure’ or ‘unknown’ in combination with other ordinal categories, while taking additional hierarchical data structures into account. The latter is achieved by the use of different covariance structures for a trivariate random effect. The models are applied to data from the INSIDA survey, where interest goes to the effect of covariates on the association between HIV risk perception (quadrinomial with an ‘unknown risk’ category) and HIV infection status (binary). The final model combines continuation-ratio with cumulative link logits for the risk perception, together with partly correlated and partly shared trivariate random effects for the household level. The results indicate that only age has a significant effect on the association between HIV risk perception and infection status. The proposed models may be useful in various fields of application such as social and biomedical sciences, epidemiology and public health. 相似文献
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The impact of attitudes and behavioral costs on environmental behavior: A natural experiment on household waste recycling 总被引:1,自引:0,他引:1
Numerous studies have shown the importance of incentives as well as of attitudes in explaining pro-environmental behavior. Reported attitude effects, however, are generally rather small and exhibit considerable variation among studies. Different theoretical perspectives can account for this finding: whereas theories of rational action suggest additive effects of costs and attitudes, the low-cost hypothesis and dual-process theories imply interaction effects - in different directions, resulting from different mechanisms. The present study tries to overcome the shortcomings of past research by using advanced statistical methods to test competitive hypotheses in the context of post-consumer waste recycling. We utilize data from a natural experiment on recycling participation in Cologne/Germany (n = 1882) in which the incentive structure for recycling changed due to the conversion of the recycling scheme from a drop-off system to curbside collection. In order to avoid self-selection bias, we conducted pre- and post-treatment surveys and applied conditional fixed-effects regression models. We found that curbside collection had a strong impact on recycling participation and attitudes had a moderate effect. The interaction is negative but statistically insignificant. Our findings contradict the low-cost hypothesis and provide some evidence that environmental concerns moderate the effect of the recycling scheme. We cannot, however, reject the rational choice proposition of mere additive effects. 相似文献
19.
Due to the changes in the nature of business and competition from company versus company to supply chain versus supply chain, the importance of improving the entire supply chain holistically is becoming an increasingly important topic in recent studies. Industry practitioners and academics are focusing on developing a modelling tool for this purpose. However, such efforts were unsuccessful. The main reasons for failure are that the existing models are developed and tested based on the experiences of manufacturing firms in the developed world. The nature of the existing firms, their operating and business processes situation in developing countries vary greatly from the manufacturing processes and the surrounding environment in developed countries. However, the absence of an agreed upon, common language and standardised modelling tools for the entire supply chains hampers the global supply chain improvement initiatives. This paper focuses on addressing the issue of a how standardised and widely accepted model, like the SCOR, can be applied despite the different circumstances. The firms’ supply chain characteristics and new requirement for the model adaptation were collected based on the available literature and field analysis results. The research paper results focus on the make and delivery processes for illustration and evaluation. 相似文献
20.
Susanne Grylka-Baeschlin Thorsten Meyer Luise Lengler Edwin van Teijlingen Jessica Pehlke-Milde Mechthild M. Gross 《Women and birth : journal of the Australian College of Midwives》2019,32(2):e229-e237