Countercyclical Capital Buffers: A Cautionary Tale
对比了大萧条时期（存在逆周期资本缓冲）与大衰退时期（无此缓冲）的银行行为，发现前者在繁荣期积累了相当于总资产3%至5%的资本缓冲，并减少了风险贷款、增加了现金储备，从而在危机中维持了核心银行运营，但质疑现代缓冲能否真正促进整体金融稳定。
Abstract Countercyclical capital buffers (CCyBs) are an old idea recently resurrected. They compel systemically important banks to accumulate capital during expansions to sustain operations during downturns. We compare banks before the Great Depression, when CCyBs existed, and Great Recession, when they did not. Pre‐Depression systemically important banks built capital buffers between 3% and 5% of total assets during booms, nearly twice the maximum modern CCyB, while also reducing risky lending and building cash reserves. These buffers enabled banks at the core of the financial system to continue operations during severe crises while the rest of the financial system collapsed. This analogy indicates that modern countercyclical buffers may achieve their goals of protecting core banks during crises but raises questions about whether they will contribute to overall financial stability.