新巴塞尔协议下的操作风险与我国银行业的应对策略

作为创新之一,新巴塞尔协议首次将操作风险纳入了银行资本计量与监管的范围,并对其概念与计量标准作了界定。在深入分析操作风险的内涵和特征的基础上,阐述了操作风险主要计量方法的内容及其适用性,并针对我国操作风险管理的实际情况,从构建责权明晰的风险管理架构,推进高级风险计量模型开发等方面提出了具体对策与建议。     

商业银行操作风险的特征、成因及控制

商业银行操作风险的主要形式是欺诈,具有反控制、容易被能人所做、营销所为以及指标所驱的外包装所掩盖等特征;商业银行操作风险的成因包括内控的过程管理流于形式,对操作风险的认识不足,传统的管理观念和习惯影响组织执行力的发挥,对操作风险的管控缺乏历史数据支持和经验积累,对风险管理控制工作的职责认识存在偏差,业务创新加大操作风险概率等。商业银行为了改进操作风险管控体系必须加强内部控制制度建设,提高内控部门在防范银行操作风险中的监督作用,完善银行的公司治理结构,构建内控发展系统的整体框架。     

A mixture model for credit card exposure at default using the GAMLSS framework

The Basel II and III Accords propose estimating the credit conversion factor (CCF) to model exposure at default (EAD) for credit cards and other forms of revolving credit. Alternatively, recent work has suggested it may be beneficial to predict the EAD directly, i.e.modelling the balance as a function of a series of risk drivers. In this paper, we propose a novel approach combining two ideas proposed in the literature and test its effectiveness using a large dataset of credit card defaults not previously used in the EAD literature. We predict EAD by fitting a regression model using the generalised additive model for location, scale, and shape (GAMLSS) framework. We conjecture that the EAD level and risk drivers of its mean and dispersion parameters could substantially differ between the debtors who hit the credit limit (i.e.“maxed out” their cards) prior to default and those who did not, and thus implement a mixture model conditioning on these two respective scenarios. In addition to identifying the most significant explanatory variables for each model component, our analysis suggests that predictive accuracy is improved, both by using GAMLSS (and its ability to incorporate non-linear effects) as well as by introducing the mixture component.     

The Fundamental Review of the Trading Book: Implications for Portfolio and Risk Management in the Banking Sector

The Fundamental Review of the Trading Book (FRTB) is the promised overhaul of bankmarket risk regulation. FRTB retains the authorized use of proprietary risk models, however, it introduces two additional criteria: (i) P&L attribution (PLA) tests and (ii) desk-level backtests. We examine empirically whether these additional criteria influence risk management and portfolio management practice, specifically portfolio construction and choice of risk model. We find that the PLA tests demand significant alignment with risk factors, however, the backtests do not incentivize use of superior risk models. This has important implications for the efficacy of the capital-based regulatory system.     

Liquidity and bank capital structure

Bank capital requirements reduce the probability of bank failure and help mitigate taxpayers’ sharing in the losses that result from bank failures. Under Basel III, direct capital requirements are supplemented with liquidity requirements. Our results suggest that liquidity provisions of banks are connected to bank capital and that changes in liquidity indirectly affect the capital structure of financial institutions. Liquidity appears to be another instrument for adjusting bank capital structure beyond just capital requirements. Consistent with Diamond and Rajan (2005), we find that liquidity and capital should be considered jointly for promoting financial stability.     

Risk shifting and regulatory arbitrage: Evidence from operational risk

We document a robust negative relation between operational risk exposure and bank capital levels for a sample of large U.S. banks under the Basel I Capital Accords. The results are consistent with the notion that capital-constrained banks increased operational risk exposure at the time when Basel I regulations did not require an explicit capital charge for operational risk. More broadly, our results show new channel by which financial regulations incentivize banks to shift their risk taking to less regulated risk areas. We focus on the case of operational risk because it went from a largely unregulated risk type to a major risk that accounts for about 25% of large U.S. banks’ risk-weighted assets.     

次贷危机对中国推行新巴塞尔协议的启示

通过分析次贷危机中商业银行扮演的角色,以及新旧资本协议的比较,说明新资本协议的制度先进性、适应性和前瞻性.次贷危机不仅未否认新资本协议,反而进一步凸现了全面实施新资本协议的重要性.严格执行新资本协议未必能阻止金融危机的爆发,但至少可以缓解危机的破坏力,从而提升金融系统的稳定性.中国宜加快推进新巴塞尔协议,资产证券化是一个很好的切入点.     

From BASEL III to BASEL IV and beyond: Expected shortfall and expectile risk measures

The article contributes to the ongoing search for a market risk measure that is both coherent and elicitable. We compare two traditional measures, namely Value-at-Risk and the expected shortfall, with another relatively novel one established on the expectile probability term. Our research is based on five models: Black–Scholes, exponential tempered stable, Heston, Bates and another stochastic volatility model with a tempered stable jump correction. We apply the general Fourier inversion formula to derive closed form formulas for calculating not only the expectile based risk measure but also the Value-at-Risk and the expected shortfall. These models are calibrated by combining nonlinear programming with simulated annealing at a moving window. Additionally, we compare the generated values of the risk measures with the real ones. Last but not least, we modify the expectile based risk measure as well as the expected shortfall by introducing correction coefficients.     

Impact of Basel III liquidity regulations on U.S. Bank performance in different conditional profitability spectrums

We study the impact of the Basel III liquidity constraints, represented by the liquidity coverage ratio (LCR) and the net stable funding ratio (NSFR), on bank profitability, by employing the simultaneous quantile regression framework with time fixed effects. We find a positive and significant relationship between the LCR and profitability and the NSFR and profitability over most quantiles. However, the small magnitudes of the coefficients on LCR and NSFR across all quantiles of profitability suggest that LCR and NSFR have a minor quantitative impact on bank profitability. We then test and find that the Basel III liquidity constraints have a significantly different impact on banks with very low profits compared to banks who enjoy high profitability, emphasizing the need to use a quantile approach. We plot the coefficients to illustrate the impact of liquidity constraints across different conditional profitability spectrums. Lastly, we find that small banks are more vulnerable to short term liquidity risks (LCR) and big banks are more susceptible to medium to long term liquidity risks (NSFR). This suggests that considerations should be given to tailoring liquidity regulations based on the bank size and the relative bank profitability. The quantitatively small impact of the constraints suggest that Basel III has successfully set liquidity requirements to minimize the impact on bank profitability and the likelihood of an industry-wide liquidity crisis.     

A Dilemma between Liquidity Regulation and Monetary Policy: Some History and Theory

History suggests a conflict between current Basel III liquidity ratios and monetary policy, which we call the liquidity regulation dilemma. Although forgotten, liquidity ratios, named “securities-reserve requirements,” were widely used historically, but for monetary policy (not regulatory) reasons, as central bankers recognized the contractionary effects of these ratios. We build a model rationalizing historical policies: a tighter ratio reduces the quantity of assets that banks can pledge as collateral, thus increasing interest rates. Tighter liquidity regulation paradoxically increases the need for central bank's interventions. Liquidity ratios were also used to keep yields on government bonds low when monetary policy tightened.