Discretionary Capital Buffers and Bank Risk

This paper examines the association between discretionary capital buffers, capital requirements, and risk for European banks. The discretionary buffers are banks' own buffers, or headroom: the difference between reported and required capital. I exploit capital requirements data that banks started to disclose since the release of a 2015 European Banking Authority opinion. Results using detailed SREP and Pillar 2 data of the largest 99 European banks over 2013-2019 show that less headroom is associated with increased bank risk. An additional examination reveals a positive association between headroom and stress test results for banks subjected to the Single Supervisory Mechanism, a result that runs against supervisory requirements.