Network risk and key players: a structural analysis of interbank liquidity

Using a structural model, we estimate the liquidity multiplier of an interbank network and banks’ contributions to systemic risk. To provide payment services, banks hold reserves. Their equilibrium holdings can be strategic complements or substitutes. The former arises when payment velocity and multiplier are high. The latter prevails when the opportunity cost of liquidity is large, incentivising banks to borrow neighbors’ reserves instead of holding their own. Consequently, the network can amplify or dampen shocks to individual banks. Empirically, network topology explains cross-sectional heterogeneity in banks’ systemic-risk contributions while changes in the equilibrium type drive time-series variation.