Takeaway Trust: A market data perspective on reputation portability in electronic commerce

Reputation has become a key factor within today’s online platform landscape. In particular for sellers in electronic commerce, the management of reputation as a signal of trustworthiness has become a relevant business activity. Prior studies have focused on either the role of reputation within given (but platform-bound) environments or general data portability between platforms. The question of cross-platform reputation portability, however, has thus far achieved much less attention. With this exploratory work, we present survey data on consumers’ perception of portable reputation in the platform economy and a case study based on actual (seller) market data from an e commerce marketplace. Our results show that consumers are generally receptive for imported seller reputation. However, for seller ratings to function as an effective signaling device across platform boundaries, adequate means of representation have yet to be found

Economic optimization of component sizing for residential battery storage systems

Battery energy storage systems (BESS) coupled with rooftop-mounted residential photovoltaic (PV) generation, designated as PV-BESS, draw increasing attention and market penetration as more and more such systems become available. The manifold BESS deployed to date rely on a variety of different battery technologies, show a great variation of battery size, and power electronics dimensioning. However, given today's high investment costs of BESS, a well-matched design and adequate sizing of the storage systems are prerequisites to allow profitability for the end-user. The economic viability of a PV-BESS depends also on the battery operation, storage technology, and aging of the system. In this paper, a general method for comprehensive PV-BESS techno-economic analysis and optimization is presented and applied to the state-of-art PV-BESS to determine its optimal parameters. Using a linear optimization method, a cost-optimal sizing of the battery and power electronics is derived based on solar energy availability and local demand. At the same time, the power flow optimization reveals the best storage operation patterns considering a trade-off between energy purchase, feed-in remuneration, and battery aging. Using up to date technology-specific aging information and the investment cost of battery and inverter systems, three mature battery chemistries are compared; a lead-acid (PbA) system and two lithium-ion systems, one with lithium-iron-phosphate (LFP) and another with lithium-nickel-manganese-cobalt (NMC) cathode. The results show that different storage technology and component sizing provide the best economic performances, depending on the scenario of load demand and PV generation.Web of Science107art. no. 83

In Stars We Trust – A Note on Reputation Portability Between Digital Platforms

Complementors accumulate reputation on an ever-increasing number of online platforms. While the effects of reputation within individual platforms are well-understood, its potential effectiveness across platform boundaries has received much less attention. This research note considers complementors’ ability to increase their trustworthiness in the eyes of prospective consumers by importing reputational data from another platform. The study evaluates this potential lever by means of an online experiment, during which specific combinations of on-site and imported rating scores are tested. Results reveal that importing reputation can be advantageous – but also detrimental, depending on ratings’ values. Implications for complementors, platform operators, and regulatory bodies concerned with online reputation are considered

Understanding the Platform Economy: Signals, Trust, and Social Interaction

Two-sided markets are gaining increasing importance. Examples include accommodation and car sharing, resale, shared mobility, crowd work, and many more. As these businesses rely on transactions among users, central aspects to virtually all platforms are the creation and maintenance of trust. While research has considered effects of trust-building on diverse platforms in isolation, the overall platform landscape has received much less attention. However, cross-platform comparison is important since platforms vary in their degree of social interaction, which, as we demonstrate in this paper, determines the adequacy and use of different trust mechanisms. Based on actual market data, we examine the mechanisms platforms employ and how frequent users rely on them. We contrast this view against survey data on users’ perceptions of the context-specific importance of these trust-building tools. Our findings provide robust evidence for our reasoning on the relation between platforms’ degree of social interaction and the associated expressive trust cues

Aufsätze zu Vertrauen und Reputationsportabilität in digitalen Plattformökosystemen

Digital platforms increasingly shape product and service offerings around the world, change consumer behavior, and disrupt a broad variety of traditional industries. In these digital markets, to create trust and realize transactions, platform users and businesses alike rely on their accumulated online reputation such as star ratings and reviews. With the multiplicity of existing and quickly surfacing platforms and business models, reputation portability has emerged as a nascent research topic in Information Systems and adjacent fields. From a theoretical, empirical, and practical perspective, the possibility to transfer online reputation across platform ecosystems and services is a complex and constantly evolving issue. This cumulative dissertation provides a first holistic view on central dimensions of this novel topic by investigating the foundations, the economics, and the design of reputation portability in digital platform ecosystems. At the outset, general dynamics of trust-building, reputation, and data portability are formally introduced and conceptualized. Subsequently, from a user’s perspective, the economic effectiveness of porting reputation across electronic markets is evaluated in a case study leveraging platform data and by applying survey-based and experimental research. Thereafter, technological, and legal requirements, as well as practical design guidelines to implement adequate reputation portability mechanisms, are derived. Throughout, this work considers the broader societal implications for individuals’ digital sovereignty and identity management in online environments and, finally, concludes by providing an outlook with avenues for future research.Digitale Plattformen prägen zunehmend Produkt- und Dienstleistungsangebote auf der ganzen Welt, verändern Konsument*innenverhalten und disruptieren eine Vielzahl traditioneller Branchen. Als Signal für Vertrauenswürdigkeit in digitalen Märkten und zur Realisierung von Transaktionen, verlassen sich Plattformnutzer*innen und Unternehmen gleichermaßen auf ihre angesammelte Online-Reputation – zumeist in Form von Sternebewertungen und/oder geschriebenem Feedback (d.h. Reviews). Aufgrund der großen Menge existierender und zahlreich neu entstehender Plattformen und Geschäftsmodelle, hat sich die Übertragbarkeit von Reputation zu einem eigenständigen Forschungsgegenstand in der Wirtschaftsinformatik und angrenzenden Bereichen entwickelt. Aus theoretischer, empirischer und praktischer Sicht ist die Portierung von Online-Reputation zwischen Plattformen und digitalen Diensten, ein komplexes und sich stetig veränderndes Forschungsfeld. Diese kumulative Dissertation bietet einen ersten ganzheitlichen Blick auf zentrale Dimensionen dieses neuartigen Phänomens, indem sie die Grundlagen, die ökonomische Wirkungsweise sowie das Design von Reputationsportabilität in digitalen Plattform-Ökosystemen untersucht. Eingangs werden in dieser Arbeit die allgemeinen Voraussetzungen von Vertrauensbildung, Reputation und Datenportabilität formal eingeführt und konzeptualisiert. Anschließend wird die ökonomische Effektivität von Reputationsportabilität in elektronischen Märkten aus Nutzer*innensicht beleuchtet. Dazu wird eine Fallstudie beruhend auf Plattformdaten und unter Anwendung umfragebasierter und experimenteller Forschung durchgeführt. Schließlich werden technologische und rechtliche Anforderungen sowie praktische Gestaltungsrichtlinien zur Implementierung adäquater Mechanismen für Reputationsportabilität abgeleitet. Im weiteren Verlauf erörtert die Arbeit gesellschaftliche Implikationen für die digitale Souveränität von Bürger*innen und das Management von Online-Identität, um alsdann einen Ausblick auf zukünftige Forschungsfragen zu geben

Bring your own stars – The economics of reputation portability

Online reputation represents an important driver for platform-mediated transactions. Reputation portability captures the notion of allowing users to transfer their reputation – often in the form of numerical rating scores – from one platform to another. The effectiveness of reputation as a driver of trustworthiness within platforms is well-understood. However, the benefits of porting reputation across platform boundaries are unclear as there is still little empirical evidence. In this article, we employ a multi-method approach to evaluate the interplay of on-site and imported reputation. First, we report results from an online experiment, showing that imported ratings represent a powerful source of online trust. Moreover, we provide a rationale for complementors deciding on whether or not to import reputation. Second, based on empirical data from an actual e-commerce platform, we investigate complementors’ ability to attract demand through importing ratings. Last, we sketch out a field experiment to evaluate external validity and effectiveness of reputation portability in the wild

Gazing at the Stars: How Signal Discrepancy Affects Purchase Intentions and Cognition

Consumers interact with reputation signals such as star ratings in many online environments. Reputation portability has been proposed as an emerging application to leverage said signals across platform boundaries. While first research demonstrates the general trust building potential of portable reputation, the cognitive and economic effects of simultaneously available signals from different sources – especially when the information is conflicting – have thus far received only little research attention. In this study, we address the gap, using a multi method approach. First, we assess the impact of rating discrepancy on consumer purchase intentions by means of an online experiment. We find that imported ratings are a driver of purchase intentions on digital platforms, but, also that a higher rating discrepancy is detrimental. Second, we propose a study design to analyze the underlying cognitive processes that may contribute to explain consumers’ decision making in the presence of discrepant signals using eye-tracking

Fundamentals of Using Battery Energy Storage Systems to Provide Primary Control Reserves in Germany

The application of stationary battery storage systems to German electrical grids can help with various storage services. This application requires controlling the charge and discharge power of such a system. For example, photovoltaic (PV) home storage, uninterruptible power supply, and storage systems for providing ancillary services such as primary control reserves (PCRs) represent battery applications with positive profitability. Because PCRs are essential for stabilizing grid frequency and maintaining a robust electrical grid, German transmission system operators (TSOs) released strict regulations in August 2015 for providing PCRs with battery storage systems as part of regulating the International Grid Control Cooperation (IGCC) region in Europe. These regulations focused on the permissible state of charge (SoC) of the battery during nominal and extreme conditions. The concomitant increased capacity demand oversizing may result in a significant profitability reduction, which can be attenuated only by using an optimal parameterization of the control algorithm for energy management of the storage systems. In this paper, the sizing optimization is achieved and a recommendation for a control algorithm that includes the appropriate parameters for the requirements in the German market is given. Furthermore, the storage cost is estimated, including battery aging simulations for different aging parameter sets to allow for a realistic profitability calculation

A PSO-Optimized Fuzzy Logic Control-Based Charging Method for Individual Household Battery Storage Systems within a Community

Self-consumption of household photovoltaic (PV) storage systems has become profitable for residential owners under the trends of limited feed-in power and decreasing PV feed-in tariffs. For individual PV-storage systems, the challenge mainly lies in managing surplus generation of battery and grid power flow, ideally without relying on error-prone forecasts for both generation and consumption. Considering the large variation in power profiles of different houses in a neighborhood, the strategy is also supposed to be beneficial and applicable for the entire community. In this study, an adaptable battery charging control strategy is designed in order to obtain minimum costs for houses without any meteorological or load forecasts. Based on fuzzy logic control (FLC), battery state-of-charge (SOC) and the variation of SOC (∆SOC) are taken as input variables to dynamically determine output charging power with minimum costs. The proposed FLC-based algorithm benefits from the charging battery as much as possible during the daytime, and meanwhile properly preserves the capacity at midday when there is high possibility of curtailment loss. In addition, due to distinct power profiles in each individual house, input membership functions of FLC are improved by particle swarm optimization (PSO) to achieve better overall performance. A neighborhood with 74 houses in Germany is set up as a scenario for comparison to prior studies. Without forecasts of generation and consumption power, the proposed method leads to minimum costs in 98.6% of houses in the community, and attains the lowest average expenses for a single house each year