The hyperbolic geometry of financial networks

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Martin Keller-Ressel - (Author)
  • Stephanie Nargang - (Author)

Abstract

Based on data from the European banking stress tests of 2014, 2016 and the transparency exercise of 2018 we construct networks of European banks and demonstrate that the latent geometry of these financial networks can be well-represented by geometry of negative curvature, i.e., by hyperbolic geometry. Using two different hyperbolic embedding methods, hydra+ and Mercator, this allows us to connect the network structure to the popularity-vs-similarity model of Papdopoulos et al., which is based on the Poincare disc model of hyperbolic geometry. We show that the latent dimensions of 'popularity' and 'similarity' in this model are strongly associated to systemic importance and to geographic subdivisions of the banking system, independent of the embedding method that is used. In a longitudinal analysis over the time span from 2014 to 2018 we find that the systemic importance of individual banks has remained rather stable, while the peripheral community structure exhibits more (but still moderate) variability. Based on our analysis we argue that embeddings into hyperbolic geometry can be used to monitor structural change in financial networks and are able to distinguish between changes in systemic relevance and other (peripheral) structural changes.

Details

Original languageEnglish
Article number4732
Number of pages12
JournalScientific reports
Volume11
Issue number1
Publication statusPublished - 26 Feb 2021
Peer-reviewedYes

External IDs

Scopus 85101995432

Keywords

Keywords

  • CONTAGION, financial network, hyperbolic embedding, banking system