Financial networks, systemic risk, contagion, regulation, network topology

C63, G01, G21

In this paper we contribute to the debate on macro-prudential regulation by assessing which structure of the nancial system is more resilient to exogenous shocks, and which conditions, in terms of balance sheet compositions, capital requirements and asset prices, guarantee the higher degree of stability. We use techniques drawn from the theory of complex networks to show how contagion can propagate under dierent scenarios when the topology of the nancial system, the characteristics of the nancial institutions, and the regulations on capital are let vary. First, we benchmark our results using a simple model of contagion as the one that has been popularized by Gai and Kapadia (2010). Then, we provide a richer model in which both short- and long-term interbank markets exist. By doing so, we study how liquidity shocks (de)stabilize the system under dierent market conditions. Our results demonstrate how connectivity, the topology of the markets and the characteristics of the nancial institutions interact in determining the stability of the system.