Pricing in Social Networks with Negative Externalities

We study the problems of pricing an indivisible product to consumers who are embedded in a given social network. The goal is to maximize the revenue of the seller. We assume impatient consumers who buy the product as soon as the seller posts a price not greater than their values of the product. The product's value for a consumer is determined by two factors: a fixed consumer-specified intrinsic value and a variable externality that is exerted from the consumer's neighbors in a linear way. We study the scenario of negative externalities, which captures many interesting situations, but is much less understood in comparison with its positive externality counterpart. We assume complete information about the network, consumers' intrinsic values, and the negative externalities. The maximum revenue is in general achieved by iterative pricing, which offers impatient consumers a sequence of prices over time. We prove that it is NP-hard to find an optimal iterative pricing, even for unweighted tree networks with uniform intrinsic values. Complementary to the hardness result, we design a 2-approximation algorithm for finding iterative pricing in general weighted networks with (possibly) nonuniform intrinsic values. We show that, as an approximation to optimal iterative pricing, single pricing can work rather well for many interesting cases, but theoretically it can behave arbitrarily bad

Ground-State Dynamical Correlation Functions: An Approach from Density Matrix Renormalization Group Method

A numerical approach to ground-state dynamical correlation functions from Density Matrix Renormalization Group (DMRG) is developed. Using sum rules, moments of a dynamic correlation function can be calculated with DMRG, and with the moments the dynamic correlation function can be obtained by the maximum entropy method. We apply this method to one-dimensional spinless fermion system, which can be converted to the spin 1/2 Heisenberg model in a special case. The dynamical density-density correlation function is obtained.Comment: 11 pages, latex, 4 figure

Optimization of techniques for multiple platform testing in small, precious samples such as human chorionic villus sampling

BackgroundMultiple testing to understand global changes in gene expression based on genetic and epigenetic modifications is evolving. Chorionic villi, obtained for prenatal testing, is limited, but can be used to understand ongoing human pregnancies. However, optimal storage, processing and utilization of CVS for multiple platform testing have not been established.ResultsLeftover CVS samples were flash-frozen or preserved in RNAlater. Modifications to standard isolation kits were performed to isolate quality DNA and RNA from samples as small as 2-5 mg. RNAlater samples had significantly higher RNA yields and quality and were successfully used in microarray and RNA-sequencing (RNA-seq). RNA-seq libraries generated using 200 versus 800-ng RNA showed similar biological coefficients of variation. RNAlater samples had lower DNA yields and quality, which improved by heating the elution buffer to 70 °C. Purification of DNA was not necessary for bisulfite-conversion and genome-wide methylation profiling. CVS cells were propagated and continue to express genes found in freshly isolated chorionic villi.ConclusionsCVS samples preserved in RNAlater are superior. Our optimized techniques provide specimens for genetic, epigenetic and gene expression studies from a single small sample which can be used to develop diagnostics and treatments using a systems biology approach in the prenatal period. © 2016 John Wiley & Sons, Ltd

Impacts of social embeddeness on IOS planning effectiveness: a multilevel perspective

This conceptual paper introduces the logic of embeddedness as a new theoretical angle to the IS planning stream of research. Taking two levels of analysis into account, we examine the impact of socially embedded ties on strategic interorganizational system (IOS) planning. We propose that from a dyad perspective, embedded ties facilitate the planning process, and can significantly increase the number of identified systems and their potential strategic value. Yet, paradoxically, having solely embedded ties in a network can adversely impact planning effectiveness by increasing (a) the risks of being insulated from novel ideas, (b) the likelihood of a lock-in effect, and (c) the salience of isomorphic pressures. We argue that, from a network perspective, those firms that manage to exploit an integrated mix of both embedded and arm’s length ties are more likely to succeed in their IOS planning. This paper contributes to SISP theory by identifying new interorganizational-level antecedents of planning effectiveness. It provides guidelines that IS executives can use to improve the effectiveness of their planning activities and ultimately achieve superior IT-business alignment

Towards a typological theory of organizational IT innovation adoption

Through a review and synthesis of literature in IS and reference disciplines, a typological theory of organizational IT innovation adoption is developed. The theory goes beyond simple linear additive (or multiplicative) effects in the traditional paradigm of IT innovation research, and proposes that Ideal Types of IT adoption are outcomes of synergy among four typology constructs: IT Adoption Mechanism, Diffusion Source, IT Innovation Characteristics, and Organizational Characteristics. It then describes the resulting four ideal types (holistic configurations), namely, IT adoption for Efficiency Increment, IT adoption for Organizational Transformation, IT adoption for Compliance, and IT adoption for Prestige. This theory aims at resolving a number of limitations and inconsistencies found in the traditional paradigm of IT innovation diffusion research

Towards a process theory of IT fashion entrepreneurship

This theory-generative research synthesis builds on IT innovation, management fashion, and social movement literatures, and puts forward a process model of IT fashion entrepreneurship. The model explains how IT fashion-setters seize IT and institutional opportunities for creating a new IT fashion frame. This frame would in turn inspire and legitimate further adoption of the IT fashion. The paper seeks to shed light on an important, yet under-studied, mechanism of IT innovation diffusion, i.e. theorization. The proposed model paves the path towards departure from the dominant paradigm in IT diffusion research

Coevolution in management fashion: an agent-based model of consultant-driven innovation

The rise of management consultancy has been accompanied by increasingly marked faddish cycles in management techniques, but mechanisms that underlie this relationship are not well understood. We develop a simple agent-based framework that models innovation adoption and abandonment on both the supply- and demand-side. In opposition to conceptions of consultants as rhetorical wizards who engineer waves of management fashion, firms and consultants are treated as boundedly rational actors who chase the secrets of success by mimicking their highest performing peers. Computational experiments demonstrate that consultant-driven versions of this dynamic – where the outcomes of firms are strongly conditioned by their choice of consultant – are robustly faddish. The invasion of boom markets by low-quality consultants undercuts popular innovations while simultaneously re-starting the fashion cycle by prompting the flight of high-quality consultants into less densely occupied niches. Computational experiments also indicate conditions involving consultant mobility, aspiration levels, mimic probabilities, and client-provider matching that attenuate faddishness

The ongoing quest for the IT artifact: looking back, moving forward

More than 10 years ago, Orlikowski and Iacono (2001) examined the conceptualization of Information Technology (IT) in Information Systems Research (ISR) articles published in the 1990s. Their main conclusion was that the majority of these articles did not properly conceptualize the IT artifact. They recommended that IS researchers start to theorize about the IT artifact and employ rich conceptualizations of IT. The Orlikowski and Iacono paper provides a strong anchor point from which to analyze the evolution of the IS discipline. In order to obtain an up-to-date image of contemporary IS research, and to assess how the IS field has evolved since the 1990s, we carried out a similar analysis on a more recent and broader set of articles, that is, the full set (N=644) of papers published between 2006 and 2009 by six top North American (ISR, MISQ, JAIS) and European (JIT, ISJ, EJIS) journals. The statistics in our results reveal no drastic advance in terms of deeper engagement with the IT artifact; more than 39% of the articles in our set are virtually mute about the artifact, and less than 16% employ an ensemble view of IT. Moreover, we note differences among the North American and European journals. Implications of the findings for two perspectives central to the IS research legitimacy debate are discussed

Health information technologies in geriatrics and gerontology: a mixed systematic review

Objective: To review, categorize, and synthesize findings from the literature about the application of health information technologies in geriatrics and gerontology (GGHIT). Materials and Methods: This mixed-method systematic review is based on a comprehensive search of Medline, Embase, PsychInfo and ABI/Inform Global. Study selection and coding were performed independently by two researchers and were followed by a narrative synthesis. To move beyond a simple description of the technologies, we employed and adapted the diffusion of innovation theory (DOI). Results: 112 papers were included. Analysis revealed five main types of GGHIT: (1) telecare technologies (representing half of the studies); (2) electronic health records; (3) decision support systems; (4) web-based packages for patients and/or family caregivers; and (5) assistive information technologies. On aggregate, the most consistent finding proves to be the positive outcomes of GGHIT in terms of clinical processes. Although less frequently studied, positive impacts were found on patients’ health, productivity, efficiency and costs, clinicians’ satisfaction, patients’ satisfaction and patients’ empowerment. Discussion: Further efforts should focus on improving the characteristics of such technologies in terms of compatibility and simplicity. Implementation strategies also should be improved as trialability and observability are insufficient. Conclusions: Our results will help organizations in making decisions regarding the choice, planning and diffusion of GGHIT implemented for the care of older adults