Pathways towards instability in financial networks

• Published in: Nature communications Vol. 8; no. 1; p. 14416
• Main Authors: Bardoscia, Marco, Battiston, Stefano, Caccioli, Fabio, Caldarelli, Guido
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 21.02.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 639/705/1041; 639/766/530/2801; 706/689/159; Banks; Default; Ecologists; Equity; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary); United Kingdom > UK
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms14416

Following the financial crisis of 2007–2008, a deep analogy between the origins of instability in financial systems and complex ecosystems has been pointed out: in both cases, topological features of network structures influence how easily distress can spread within the system. However, in financial network models, the details of how financial institutions interact typically play a decisive role, and a general understanding of precisely how network topology creates instability remains lacking. Here we show how processes that are widely believed to stabilize the financial system, that is, market integration and diversification, can actually drive it towards instability, as they contribute to create cyclical structures which tend to amplify financial distress, thereby undermining systemic stability and making large crises more likely. This result holds irrespective of the details of how institutions interact, showing that policy-relevant analysis of the factors affecting financial stability can be carried out while abstracting away from such details. The spread of instabilities in financial systems, similarly to ecosystems, is influenced by topological features of the underlying network structures. Here the authors show, independently of specific financial models, that market integration and diversification can drive the system towards instability.