ON THE PERFORMANCE OF NONPARAMETRIC SPECIFICATION TESTS IN REGRESSION MODELS

Some recently developed nonparametric specification tests for regression models are described in a unified way. The common characteristic of these tests is that they are consistent against any alternative hypothesis. The performance of the test statistics is compared by means of Monte Carlo simulations, analysing how heteroskedasticity, number of regressors and bandwidth selection influence the results. The statistics which do not use a bandwidth perform slightly better if the regression model has only one regressor; otherwise, some of the statistics which use a bandwidth behave better if the bandwidth is chosen adequately. These statistics are applied to test the specification of three commonly used Mincer-type wage equations with Uruguayan and Spanish data; all of them are rejected.

Selective demarketing: When customers destroy value.

Selective demarketing is a strategic option for firms to manage customers who are or are likely to be a poor fit with its offering. Research has investigated related areas such as customer profitability and relationship dissolution but, as yet, studies have not offered a robust conceptualisation of selective demarketing. Based on research into value co-destruction, this study argues that these customers effectively destroy value by misusing or misunderstanding how to integrate their operant resources with those of the firm. As firms exist within a wider service system, this failure to integrate resonates throughout the system. To demarket selectively, firms use higher order operant resources to disengage and discourage these customers. This study offers a novel conceptualisation of selective demarketing and extends research on value destruction through adopting a firm and systems perspective

An Experimentally Realizable Weiss Model for Disorder-Free Glassiness

We summarize recent work on a frustrated periodic long-range Josephson array in a parameter regime where its dynamical behavior is identical to that of the $p=4$ disordered spherical model. We also discuss the physical requirements imposed by the theory on the experimental realization of this superconducting network.Comment: 6 pages, LaTeX, 2 Postscript figure

Mapping the systematic literature studies about software ecosystems

There is a need to improve the definition and development of technological ecosystems in order to solve the main problems detected in previous studies. To achieve this goal, it is required to identify and analyse the solutions available in the literature in the field of software engineering applied to ecosystems. The research in software ecosystems is a relatively young research area, but there are already several works that analyse the literature associated. To conduct a new systematic literature review is necessary to ensure that there are no studies that do the same, namely, that do not answer the same research questions. The identification of the need for a review was done through a study focused on systematic literature reviews and mapping studies about software ecosystems. This work aims to describe the mapping conducted as part of that study. It provides a global state of the art of this kind of studies in the area of software ecosystems

A Paradigmatic Analysis of Digital Application Marketplaces

This paper offers a paradigmatic analysis of digital application marketplaces for advancing information systems (IS) research on digital platforms and ecosystems. We refer to the notion of digital application marketplace, colloquially called “appstores,” as a platform component that offers a venue for exchanging applications between developers and end-users belonging to a single or multiple ecosystems. Such marketplaces exhibit diversity in features and assumptions, and we propose that examining this diversity, and its ideal types, will help us to further understand the relationship between application marketplaces, platforms, and platform ecosystems. To this end, we generate a typology that distinguishes four kinds of digital application marketplaces: closed, censored, focused, and open marketplaces. The paper also offers implications for actors wishing to make informed decisions about their relationship to a particular digital application marketplace

The Velvet Cage of Educational Con(pro)sumption

In the year that George Ritzer publishes the ninth edition of The McDonaldization of Society, moving his famous theory firmly Into the Digital Age, critical educator Petar Jandrić and sociologist Sarah Hayes invited George to a dialogue on the digital transformation of McDonaldization and its relationship to consumer culture. In this article, George first traces for us the origins of his theory that has endured for four decades. A key dimension of McDonaldization is the ‘iron cage’ of control, via rationalization, that was once contained within physical sites of bricks and mortar. Increasingly now, we encounter a ‘velvet cage’ in sites of digital consumption, at the hands of non-human technologies, that threaten human labour and autonomy. Exploited as unpaid con(pro)sumers, we labour to provide information for corporate digital billionaires, keeping McDonaldization alive, well, and even more predominant in augmented settings, including Higher Education, in the form of the McUniversity. With the rise of prosuming machines such as blockchain and bitcoin, that can both produce and consume without intervention from human prosumers, George concludes that prosumer capitalism will explode into unprecedented and unpredictable directions in the years to come

Knowledge Sharing in Alliances and Alliance Portfolios

We develop a model of knowledge sharing in alliances and alliance portfolios. We show that, once the issue of encouraging effective collaboration is put center stage, many standard intuitions of the learning race view and alliance portfolio literature are overturned or qualified. Partners engage in learning races in some cases, but exhibit “altruistic” behaviors in other cases. They may reduce their own absorptive capacity or increase the transparency of their own operations to facilitate their partner’s learning. In alliance portfolios, we show that not all substitutability between alliance portfolio partners is bad. We distinguish between substitutability in implementation and substitutability in rival benefits and show that the latter is conducive to knowledge sharing. Our work contributes toward putting the literature on learning alliances on a more solid foundation by emphasizing the importance of commitments that leading firms can make to encourage collaboration

Macroscopic Quantum Fluctuations in the Josephson Dynamics of Two Weakly Linked Bose-Einstein Condensates

We study the quantum corrections to the Gross-Pitaevskii equation for two weakly linked Bose-Einstein condensates. The goals are: 1) to investigate dynamical regimes at the borderline between the classical and quantum behaviour of the bosonic field; 2) to search for new macroscopic quantum coherence phenomena not observable with other superfluid/superconducting systems. Quantum fluctuations renormalize the classical Josephson oscillation frequencies. Large amplitude phase oscillations are modulated, exhibiting collapses and revivals. We describe a new inter-well oscillation mode, with a vanishing (ensemble averaged) mean value of the observables, but with oscillating mean square fluctuations. Increasing the number of condensate atoms, we recover the classical Gross-Pitaevskii (Josephson) dynamics, without invoking the symmetry-breaking of the Gauge invariance.Comment: Submitte