Convergence and performance of the peeling wavelet denoising algorithm

This note is devoted to an analysis of the so-called peeling algorithm in wavelet denoising. Assuming that the wavelet coefficients of the useful signal are modeled by generalized Gaussian random variables and its noisy part by independent Gaussian variables, we compute a critical thresholding constant for the algorithm, which depends on the shape parameter of the generalized Gaussian distribution. We also quantify the optimal number of steps which have to be performed, and analyze the convergence of the algorithm. Several implementations are tested against classical wavelet denoising procedures on benchmark and simulated biological signals.     

Closed-skew normality in stochastic frontiers with individual effects and long/short-run efficiency

This paper considers the estimation of Kumbhakar et al. (J Prod Anal. doi:10.1007/s11123-012-0303-1, 2012) (KLH) four random components stochastic frontier (SF) model using MLE techniques. We derive the log-likelihood function of the model using results from the closed-skew normal distribution. Our Monte Carlo analysis shows that MLE is more efficient and less biased than the multi-step KLH estimator. Moreover, we obtain closed-form expressions for the posterior expected values of the random effects, used to estimate short-run and long-run (in)efficiency as well as random-firm effects. The model is general enough to nest most of the currently used panel SF models; hence, its appropriateness can be tested. This is exemplified by analyzing empirical results from three different applications.     

Processes in collaborative entrepreneurship: a longitudinal case study of how multiple actors exploit a radically new opportunity

In this longitudinal case study, the authors integrate the theory on social movement with the entrepreneurship literature on opportunity discovery, evaluation, and exploitation. They construct a model on collaborative entrepreneurial processes in which multiple partners are involved in identifying, forming, and exploiting an opportunity. Three interdependent subprocesses are identified: (1) the opportunity conceptualization dialogue, (2) resource mobilization and, (3) legitimacy building, which significantly contribute to our understanding of how individuals across different organizations become engaged in collaborative entrepreneurial processes. The model of collaborative entrepreneurial processes complements traditional models of the entrepreneurial process, which place the individual entrepreneur at the center of the process and does not consider group mobilization processes in which the actors aim to be creative and innovative in collaborating with actors from other organizations or firms.     

Income based price subsidies and parallel imports

We present a policy game where a Rich country has a higher ability than a Poor country to commit to certain elements of health policy such as providing income related price subsidies and allowing parallel imports (PI). When allowing PI is not a choice for the Poor country, the Rich country allows PI and both countries provide a subsidy to their poorer buyers as the subgame perfect equilibrium policies. However, when the Poor is able to PI a different equilibrium may arise. We show that the ability of the Poor to allow PI might increase welfare in this country even if it is never implemented. We also prove that as the Poor country gets richer, it will not be in their best interest to sign an agreement with the Rich to commit to not allowing PI.     

Cox Point Processes: Why One Realisation Is Not Enough

We review a rich class of point process models, Cox point processes, and illustrate the necessity of more than one observation (point patterns) in performing parameter estimation. Furthermore, we introduce a new Cox point process model by treating the intensity function of the underlying Poisson point process as a random mixture of normal components. The behaviour and performance of the new model are compared with those of popular Cox point process models. The new model is exemplified with an application that involves a single point pattern corresponding to earthquake events in California, USA.     

Stress and turnover intents in international organizations: social support and work–life balance as resources

Abstract

This study investigates whether work opportunities have an impact on stress and the related turnover intentions of employees working in intergovernmental international organizations (IOs). It contextualizes the job resources and demands model within IOs’ specific work conditions. The empirical test is based on original data from a survey administered in four major organizations of the United Nations system. Results demonstrate that social work opportunities and work–life balance are organizational levers reducing stress and willingness to quit for employees who are facing red tape or the stresses of being an expatriate. In this context, the relationships between these work opportunities and turnover intention are partially mediated by stress. Contextualized HR management propositions are made to help organizations coping with these management challenges.     

The impact of job embeddedness on innovation‐related behaviors

It has often been argued that low turnover leads to less innovation in organizations, not only because fewer job vacancies are available for outsiders with new ideas, but also because longer‐tenured employees might be more resistant to change. In this study, we propose that job embeddedness may actually strengthen employees' motivation to generate, spread, and implement innovative ideas in organizations. In a longitudinal study with a diverse sample, we found that job embeddedness was positively and significantly related to innovation‐related behaviors, even after controlling for demographic variables, the job attitudes, and the job perceptions that are frequently associated with job embeddedness. In addition, we found some support for the proposed moderating effects of career stage; that is, the relationship between job embeddedness and implementing innovative ideas was stronger for individuals in the mid‐ and late stages of their careers than for those in the early stage of their careers. This article concludes with directions for developing future theory. © 2010 Wiley Periodicals, Inc.     

INCENTIVES AND SOCIAL NORMS: A MOTIVATION‐BASED ECONOMIC ANALYSIS OF SOCIAL NORMS

Abstract It is now commonplace to regard social norms as a subject of growing interest in the economic literature (e.g. game theoretical approaches based on ‘other‐regarding’ individual preferences, the analysis of the impact of rewards or punishment on individuals’ behaviour through experimental economics as well as field experiments, the revival of the institutionalist tradition spurred on by the influential work of Douglas North and followed by many others and the growing influence of neuroeconomics). In this paper, we focus on the relationship between incentives and social norms and survey the literature that could constitute the foundations of a motivation‐based economic analysis of social norms. Our main findings are that (1) the interaction between incentives and social norms is far from obvious since taking social norms into account involves the introduction of supplementary motives, in addition to self‐interest, into the economic analytical framework; (2) the analysis of the interaction between incentives and social norms resists an approach exclusively in terms of crowding‐in and ‐out effects because it is sensitive to whether it concerns behaviours driven by honour or by social stigma; (3) as a result, it is difficult to precisely evaluate the policy implication of the interactions between incentives and social norms.