Contributions in Merlin

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Biases impair the effectiveness of algorithms. For example, the age bias of the widely-used PageRank algorithm impairs its ability to effectively rank nodes in growing networks. PageRank’s temporal bias cannot be fully explained by existing analytic results that predict a linear relation between the expected PageRank score and the indegree of a given node. We show that in evolving networks, under a mean-field approximation, the expected PageRank score of a node can be expressed as the product of the node’s indegree and a previously-neglected age factor which can “amplify” the indegree’s age bias. We use two well-known empirical networks to show that our analytic results explain the observed PageRank’s age bias and, when there is an age bias amplification, they enable estimates of the node PageRank score that are more accurate than estimates based solely on local structural information. Accuracy gains are larger in degree-degree correlated networks, as revealed by a growing directed network model with tunable assortativity. Our approach can be used to analytically study other kinds of ranking bias.

In june the imf made the latest of many calls from economists for a market-oriented policy to tackle climate change. “Carbon pricing...is the least-cost option to deliver deep emission cuts,” it argued in a paper written ahead of a meeting of the leaders of the g20 group of large economies. Carbon taxes, as this newspaper has long argued, can be a powerful way to force polluters to pay for the harm they do to the environment by burning fossil fuels.

Purpose This study investigates perceptions of the use of online tracking, a passive data collection method relying on the automated recording of participant actions on desktop and mobile devices, for studying information behavior. It scrutinizes folk theories of tracking, the concerns tracking raises among the potential participants and design mechanisms that can be used to alleviate these concerns. Design/methodology/approach This study uses focus groups composed of university students (n = 13) to conduct an in-depth investigation of tracking perceptions in the context of information behavior research. Each focus group addresses three thematic blocks: (1) views on online tracking as a research technique, (2) concerns that influence participants' willingness to be tracked and (3) design mechanisms via which tracking-related concerns can be alleviated. To facilitate the discussion, each focus group combines open questions with card-sorting tasks. The results are analyzed using a combination of deductive content analysis and constant comparison analysis, with the main coding categories corresponding to the thematic blocks listed above. Findings The study finds that perceptions of tracking are influenced by recent data-related scandals (e.g. Cambridge Analytica), which have amplified negative attitudes toward tracking, which is viewed as a surveillance tool used by corporations and governments. This study also confirms the contextual nature of tracking-related concerns, which vary depending on the activities and content that are tracked. In terms of mechanisms used to address these concerns, this study highlights the importance of transparency-based mechanisms, particularly explanations dealing with the aims and methods of data collection, followed by privacy- and control-based mechanisms. Originality/value The study conducts a detailed examination of tracking perceptions and discusses how this research method can be used to increase engagement and empower participants involved in information behavior research.

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We study the impact of the interplay between the structure of the financial network and market conditions on financial stability in the European banking system. We capture two channels of financial contagion. The first channel concerns direct interconnectedness, via a network of interbank loans, banks’ loans to other corporate and retail clients, and securities holdings. The second channel concerns indirect interconnectedness, via overlapping exposures to common asset classes. To assess the impact of contagion, we apply the structural valuation model NEVA, in which common shocks to banks’ external assets are reflected in a consistent way in the market value of banks’ mutual liabilities through the network of obligations. Applying the model to a unique supervisory data set collected by the European Central Bank that covers 26 large banks in the euro area we identify a strongly non-linear relationship between diversification of exposures, shock size, and losses due to interbank contagion. We also demonstrate the potential for contagion effects to amplify first-round stress test results due to interconnectedness. Finally, we provide insights into the potential impact of more diversified versus more domestic portfolio allocation strategies on the propagation of contagion, which are relevant to policy discussions about international risk sharing, for instance, in the context of the EU Capital Market Union.

The aim of this study was to evaluate the reproducibility of voxel-wise temporal signal-to-noise ratio (tSNR) on repeated scans across runs, sessions, and days. A group of 21 participants was scanned 16 times (4 runs per session, 2 sessions per day, 2 separate days) in a functional magnetic resonance imaging (fMRI) study on a 3T Philips Achieva scanner. For each run, we calculated t-value and tSNR maps. To ascertain that the results were not specific to the scanner, one volunteer was scanned with four fMRI runs in a single session on the above 3T Philips scanner as well as a 3T Siemens Prisma scanner. The coefficient of variation of voxel-wise tSNR across the 16 repeats was up to 25%, while the range relative to the mean of all observations was up to 80%. The voxel-wise variability of tSNR on the two different scanners was similar, indicating a general issue. Despite its use in evaluating the quality of fMRI data, we found only a weak relationship between tSNR and t-values. There is very high variability in voxel-wise tSNR, which should be considered while planning future studies that aim to identify small and focal fMRI effects or the benefits of incremental improvement in methods.

Fossil fuel investments over the past few years are at the centre of political debates about climate change policy. This article explores the role market- and bank-based debt play in the climate transition process. It presents evidence that fossil fuel firms increasingly substitute bonds for syndicated bank loans, when banks price the risk of stranded assets less than the bond market.

The notion of blockchain technology and its applications in various business domains have attracted a lot of attention. Although the most well-known application of blockchain technology is Bitcoin, its applications go far beyond cryptocurrency. In this editorial, we introduce six articles included in our special issue which encom- pass a number of important topics on blockchain technology and applications, and discuss the current status and opportunities of research in this emerging area mainly from the business perspective.

Dynamic pricing is typically implemented via pricing algorithms that react to varying levels of supply and demand. Some companies, such as Uber, also vary prices for different offers, such as standard cars or limousines for a ride. However, companies usually do not proceed to the next logical step and delegate pricing authority to their employees. This is astonishing as service employees often vary in service quality, possess unique business knowledge, hold close relationships with customers, and influence the overall customer experience. The authors investigate the consequences of delegating pricing authority to employees. They also investigate the responses of customers who face a situation where their firm transitions from fixed to dynamic prices set by the firm (control group) or service employees (treatment group). The findings demonstrate that the actual dynamic price paid affects customers’ distributive fairness perceptions, which influence their behavioral responses. The authors find support for pricing authority (firm vs. employee) acting as a second-stage moderator. The results provide supporting evidence for the stylized fact that firms keep the pricing authority with the company and do not delegate it to service employees instead.