Banks' risk-taking within a banking union

We study the relationship between banks' size and risk-taking in the context of supranational banking supervision. Consistently with theoretical work on banking unions and in contrast to analyses emphasising incentives under- pinned by the too-big-to-fail effect, we find an inverse relationship between banks' size and non-performing loan growth for a sample of European banks. Evidence is provided that the mechanism operates through the enhanced organisational efficiency of the supranational set-up rather than incentives alignment among the supervisors and the banks.