Financial networks, bank efficiency and risk-taking

• We link financial networks, bank efficiency and risk-taking.
• We show that the network structure affects bank efficiency.
• We show that core–periphery structures are cost efficient for banks.
• We show that core–periphery structures are risk-taking inefficient for banks.

Networks with a core–periphery topology are found in many financial systems across different jurisdictions. Though the theoretical and structural aspects of core–periphery networks are clear, the consequences that core–periphery structures bring for banking efficiency stand as an open question. We address this gap in the literature by providing insights as to how the structure of financial networks can affect bank efficiency. We find that core–periphery structures are cost efficient for banks, which is a characteristic that encourages the participation of banks in financial networks. On the downside, we also show that core–periphery structures are risk-taking inefficient, because they imply higher systemic risk levels in the financial system. In this way, regulators should be aware of the excessive risk inefficiency that arises in the financial system due to individual decisions made by banks in the network.