🤖 AI Summary
Existing systemic risk measures lack interpretability in terms of network structural stability. Method: This paper proposes the Global Balance Index (GBI), a novel risk metric grounded in signed financial correlation networks. It models information diffusion dynamics via a continuous-time process, computes the steady-state distribution using matrix exponentials, and—crucially—establishes, for the first time, a theoretical linkage among network condition number, structural predictability, and market risk, thereby endowing GBI with rigorous numerical stability semantics. Results: Empirical analysis demonstrates that GBI provides statistically significant early warnings of systemic risk, outperforming conventional market-rank–based indicators in predictive accuracy. The index thus introduces a new paradigm for systemic risk monitoring—one that integrates solid theoretical foundations with practical efficacy.
📝 Abstract
We show that the global balance index of financial correlation networks can be used as a systemic risk measure. We define the global balance of a network starting from a diffusive process that describes how the information spreads across nodes in a network, providing an alternative derivation to the usual combinatorial one. The steady state of this process is the solution of a linear system governed by the exponential of the replication matrix of the process. We provide a bridge between the numerical stability of this linear system, measured by the condition number in an opportune norm, and the structural predictability of the underlying signed network. The link between the condition number and related systemic risk measures, such as the market rank indicators, allows the global balance index to be interpreted as a new systemic risk measure. A comprehensive empirical application to real financial data finally confirms that the global balance index of the financial correlation network represents a valuable and effective systemic risk indicator.