Extending multi-tenant architectures: a database model for a multi-target support in SaaS applications

Multi-tenant architectures (MTAs) are considered a cornerstone in the success of Software as a Service as a new application distribution formula. Multi-tenancy allows multiple customers (i.e. tenants) to be consolidated into the same operational system. This way, tenants run and share the same application instance as well as costs, which are significantly reduced. Functional needs vary from one tenant to another; either companies from different sectors run different types of applications or, although deploying the same functionality, they do differ in the extent of their complexity. In any case, MTA leaves one major concern regarding the companies’ data, their privacy and security, which requires special attention to the data layer. In this article, we propose an extended data model that enhances traditional MTAs in respect of this concern. This extension – called multi-target – allows MT applications to host, manage and serve multiple functionalities within the same multi-tenant (MT) environment. The practical deployment of this approach will allow SaaS vendors to target multiple markets or address different levels of functional complexity and yet commercialise just one single MT application. The applicability of the approach is demonstrated via a case study of a real multi-tenancy multi-target (MT²) implementation, called Globalgest.     

OCB and external–internal social networks: effects on individual performance and adaptation to change

In this study, we develop and test a model that links one's internal and external social network structures to his or her willingness and ability to adapt in a changing work context. Using a survey data from 371 employees working in 133 different branches of a large financial firm, we find that individual behaviors that explain task performance and individual adaptation to change are affected by a number of supportive social ties (size of the support network) with which one receives support inside and, mostly, outside the workplace. The results also show that individual performance and adaptation to change are affected by the level of workers' organizational citizenship behavior. We also identify a mediating effect exerted by the informational network structure (mostly an internal network) on the relationship between the support network (mostly an external network) and individual task performance.     

Performance Measures in Dose-Finding Experiments

In the first phase of pharmaceutical development, and assuming that the probability of positive response increases with dose, the main statistical goal is to estimate a percentile of the dose–response function for a given target value $\mathrm{\Gamma }$. We compare the Maximum Likelihood and centred isotonic regression estimators of the target dose and we discuss several performance criteria to assess inferential precision, the amount of toxicity exposure and the trade-off between them for a set of some exemplary adaptive designs. We compare these designs using graphical tools. Several scenarios are considered using simulation, including the use of several start-up rules, the change of slope of the dose-toxicity function at the target dose and also different theoretical models, as logistic, normal or skew-normal distribution functions.     

Incidence,effects, dynamics and routes out of overqualification in Europe: a comprehensive analysis distinguishing by employment status

This study aims to improve our understanding of overqualification by incorporating distinctions in employment status (i.e. self-employed workers, private employees and public employees) in the analysis of the incidence, effects, dynamics and routes out of overqualification. To this end, we apply discrete choice – ordered and nonordered – and count models to the data obtained from the European Community Household Panel for the EU-15. Our results indicate that the incidence of overqualification varies by employment status, where self-employed workers report the lowest occurrence. Furthermore, this analysis suggests that overqualification is a permanent phenomenon and demonstrates that successful pathways out of overqualification differ by employment status. The implications of these results for education and labour market policies are also discussed.     

The Lindahl equilibrium in Schumpeterian growth models

The main motivation of the paper is to determine the social value of innovations in a standard scale-invariant Schumpeterian growth model, which explicitly introduces knowledge diffusion over a Salop (Bell J Econ 10(1):141–156 1979) circle. The social value of an innovation is defined as the optimal value of the knowledge inherent in this innovation. We thus have to price optimally knowledge. For that purpose, contrary to what is done in standard growth theory, we complete the markets using Lindahl prices for knowledge. The Lindahl equilibrium, which provides the system of prices that sustains the first-best social optimum in an economy with non rival goods, appears as a benchmark. First, its comparison with the standard Schumpeterian equilibrium à la Aghion and Howitt (Econometrica (60)2:323–351 1992) enables us to shed a new light on the issue of non-optimality of the latter. Second, the Lindahl equilibrium also allows us to revisit the issue of R&D incentives in presence of cumulative innovations. Finally, this benchmark may be a first step to understand how knowledge is exchanged in new technology sectors.     

Lagrangean conditions for consumers with nonrepresentable preferences

A Lagrangian characterization of the solutions of the consumer problem is provided when preferences are not representable by a continuous utility function.     

Sustainable product innovation and changing consumer behavior: Sustainability affordances as triggers of adoption and usage

This conceptual paper argues that for sustainable product innovation to make a contribution to addressing sustainability issues, we need to understand not only why consumers adopt sustainable products but also what makes them use these in sustainable way. To explain how specific product features can change the ways in which consumers engage with sustainable products in the adoption and usage phase, we draw on affordance theory. Affordances refer to the potential for agentic action of users in relation to a technological object. We develop a conceptual framework that explains how sustainable product innovation can lead to the design of sustainability affordances that stimulate adoption and sustainable usage. The framework shows how three forms of agency—material, firm, and user agency—interact and together influence a product's sustainability affordances that drive adoption and a change in consumer behavior. The framework explains how trade-offs between a product's environmental features and consumer expectations regarding desired functionalities and user experience can be overcome.     

Single currency and fiscal performance: the early Euro Area in perspective

We examine how exchange rate regimes affect fiscal discipline by investigating European countries as they transitioned from flexible to fully fixed exchange rates under the Euro. We apply the synthetic control method to estimate, for each Eurozone country, its counterfactual budget stance under flexible rates. Our evidence strongly suggests that fixing exchange rates negatively impacted negatively fiscal discipline. However, effects were not homogeneous, as they were mediated by political factors. For example, countries where policymakers faced a longer political horizon and operated within a more cohesive political environment, managed to perform better in terms of fiscal discipline.