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on Network Economics |
| By: | Mavridis, Dimitris; Nikolakopoulou, Adriani; Moustaki, Irini; Chaimani, Anna; Porcher, Raphaël; Boutron, Isabelle; Ravaud, Philippe |
| Abstract: | Objectives: Ranking metrics in network meta-analysis (NMA) are computed separately for each outcome. Our aim is to 1) present graphical ways to group competing interventions considering multiple outcomes and 2) use conjoint analysis for placing weights on the various outcomes based on the stakeholders’ preferences. Study Design and Setting: We used multidimensional scaling (MDS) and hierarchical tree clustering to visualize the extent of similarity of interventions in terms of the relative effects they produce through a random effect NMA. We reanalyzed a published network of 212 psychosis trials taking three outcomes into account as follows: reduction in symptoms of schizophrenia, all-cause treatment discontinuation, and weight gain. Results: Conjoint analysis provides a mathematical method to transform judgements into weights that can be subsequently used to visually represent interventions on a two-dimensional plane or through a dendrogram. These plots provide insightful information about the clustering of interventions. Conclusion: Grouping interventions can help decision makers not only to identify the optimal ones in terms of benefit-risk balance but also choose one from the best cluster based on other grounds, such as cost, implementation etc. Placing weights on outcomes allows considering patient profile or preferences. |
| Keywords: | clustering; conjoint analysis; multidimensional scaling; network meta analysis; ranking; weighting |
| JEL: | C1 |
| Date: | 2023–02–01 |
| URL: | http://d.repec.org/n?u=RePEc:ehl:lserod:118272&r=net |
| By: | Spatareanu, Mariana; Manole, Vlad; Kabiri, Ali; Roland, Isabelle |
| Abstract: | How does banks' default risk affect the probability of default of non-financial businesses? The literature has focused on the banks' direct corporate customers. It fails to consider the role of supply chain relationships as a powerful channel for default risk contagion. Our paper fills this gap by analyzing the direct as well as the indirect impact of banks' default risk on firms' default risk in the U.K. Relying on Input-Output tables, we devise methods that enable us to examine this question in the absence of data on firm-to-firm linkages. To capture all potential propagation channels, we account for horizontal and vertical linkages, both between the firm and upstream industries (suppliers) and between the firm and downstream industries (customers). We further examine how trade credit and contract specificity amplify or dampen the propagation of default risk. Our results show that increases in banks’ default risk from the banking crisis of 2007–2008 propagated strongly to U.K. non-financial firms via supply chains. |
| Keywords: | default risk; propagation of banking crises; supply chains |
| JEL: | G21 G34 O30 O16 |
| Date: | 2023–03–01 |
| URL: | http://d.repec.org/n?u=RePEc:ehl:lserod:117351&r=net |
| By: | Grimm Noh (Métis Lab EM Normandie - EM Normandie - École de Management de Normandie) |
| Abstract: | Creativity is becoming a necessary core competence in nearly all businesses today, and firms are striving to find ways to promote the creativity of employees. This study aimed to analyze the relationships between an individual actor's network characteristics and the actor's creativity. More specifically, this study assumed that actors qualitatively differentiate between their global and local networks depending on whether they perceive the other actors in the network as mere acquaintances or trusted persons to discuss life's important issues with. This study used large-scale survey data collected from South Korea to empirically analyze the hypothesized relationships between network characteristics and creativity. The empirical analysis of the survey data showed that the size and diversity of the global network were positively related to creativity. However, the positive effect of global network diversity decreased with an increase in the size of the network. In the local network, frequent interactions had a positive effect on creativity, while the diversity of the local network had a moderate negative effect on creativity. Implications for the creativity literature are discussed. |
| Keywords: | Creativity, Global network, Local network, Network size, Network diversity, Interaction frequency |
| Date: | 2022–04–07 |
| URL: | http://d.repec.org/n?u=RePEc:hal:journl:hal-04316668&r=net |
| By: | Gregor Svindland; Alexander Vo{\ss} |
| Abstract: | We introduce a novel class of risk measures for the management of systemic risk in networks. In contrast to most existing approaches, our measures target the topological structure of the network in order to control the risk of a pandemic spread of some contagious peril throughout the network. While the main discussion of the paper is tailored to the management of systemic cyber risk in digital networks, we also draw parallels to similar risk management frameworks for other types of complex systems. |
| Date: | 2023–12 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2312.13884&r=net |
| By: | Umberto Natale; Michael Moser |
| Abstract: | We present a comprehensive analysis of the implications of artificial latency in the Proposer-Builder Separation framework on the Ethereum network. Focusing on the MEV-Boost auction system, we analyze how strategic latency manipulation affects Maximum Extractable Value yields and network integrity. Our findings reveal both increased profitability for node operators and significant systemic challenges, including heightened network inefficiencies and centralization risks. We empirically validates these insights with a pilot that Chorus One has been operating on Ethereum mainnet. We demonstrate the nuanced effects of latency on bid selection and validator dynamics. Ultimately, this research underscores the need for balanced strategies that optimize Maximum Extractable Value capture while preserving the Ethereum network's decentralization ethos. |
| Date: | 2023–12 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2312.09654&r=net |
| By: | B. F. Oliveira; A. V. M Oliveira |
| Abstract: | This paper describes an econometric model of the Brazilian domestic carrier Azul Airlines' network construction. We employed a discrete-choice framework of airline route entry to examine the effects of the merger of another regional carrier, Trip Airlines, with Azul in 2012, especially on its entry decisions. We contrasted the estimated entry determinants before and after the merger with the benchmarks of the US carriers JetBlue Airways and Southwest Airlines obtained from the literature, and proposed a methodology for comparing different airline entry patterns by utilizing the kappa statistic for interrater agreement. Our empirical results indicate a statistically significant agreement between raters of Azul and JetBlue, but not Southwest, and only for entries on previously existing routes during the pre-merger period. The results suggest that post-merger, Azul has adopted a more idiosyncratic entry pattern, focusing on the regional flights segment to conquer many monopoly positions across the country, and strengthening its profitability without compromising its distinguished expansion pace in the industry. |
| Date: | 2023–12 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2312.05630&r=net |
| By: | Niccolò Lomys (CSEF and Università degli Studi di Napoli Federico II.); Emanuele Tarantino (Luiss University, EIEF, and CEPR) |
| Abstract: | We theoretically study the problem of a researcher seeking to identify and estimate the search cost distribution when a share of agents in the population observes some peers’ choices. To begin with, we show that social information changes agents’ optimal search and, as a result, the distributions of observable outcomes identifying the search model. Consequently, neglecting social information leads to non-identification of the search cost distribution. Whether, as a result, search frictions are under or overestimated depends on the dataset’s content. Next, we present empirical strategies that restore identification and correct estimation. First, we show how to recover robust bounds on the search cost distribution by imposing only minimal assumptions on agents’ social information. Second, we explore how leveraging additional data or stronger assumptions can help obtain more informative estimates. |
| Keywords: | Search & Learning; Social Information; Identification; Networks; Robustness; Partial Identification. |
| JEL: | C1 C5 C8 D1 D6 D8 |
| Date: | 2023–11–24 |
| URL: | http://d.repec.org/n?u=RePEc:sef:csefwp:694&r=net |