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.

We examine how COVID-19 and digitalization have changed bank lending behavior. Using microdata from Brazil, we investigate the determinants of these changes at the bank branch level and by credit type. Branches in areas more affected by COVID-19 reduced loan issuances and experienced lower credit revenues. These branches could not adjust their costs in the short term due to this decline in lending, resulting in increased marginal costs. We also find that branches of more digitalized banks were less sensitive to local borrowers’ conditions and could expand their clientele. These branches extended credit to borrowers in remote localities less affected by COVID-19, positioning themselves better than branches of less digitalized banks. Our research highlights the critical role of digitalization in distressed periods, as it enables banks to respond more swiftly and effectively, favoring financial stability.