Capital requirements under the credit risk-based framework

This work aims to study the hypothesis of lower capitalization of banks under the risk-based rules introduced in Basel II. In this sense, an assessment of the impact of these rules on the capital requirements for non-financial firms’ credit risk is performed. A comparison with Basel I is presented and intervals of variation for the risk drivers such that capital requirements exceed the ones under Basel I are established. Data for a European country supports the hypothesis of a smaller capitalization of banks under the risk-based framework, as far as credit risk in concerned.     

Optimal portfolios with minimum capital requirements

We propose a novel approach to active risk management based on the recent Basel II regulations to obtain optimal portfolios with minimum capital requirements. In order to avoid regulatory penalties due to an excessive number of Value-at-Risk (VaR) violations, capital requirements are minimized subject to a given number of violations over the previous trading year. Capital requirements are based on the recent Basel II amendments to account for the ‘stressed’ VaR, that is, the downside risk of the portfolio under extreme adverse market conditions. An empirical application for two portfolios involving different types of assets and alternative stress scenarios demonstrates that the proposed approach delivers an improved balance between capital requirement levels and the number of VaR exceedances. Furthermore, the risk-adjusted performance of the proposed approach is superior to that of minimum-VaR and minimum-stressed VaR portfolios.     

Bank regulatory capital and liquidity: Evidence from US and European publicly traded banks

The theory of financial intermediation highlights various channels through which capital and liquidity are interrelated. Using a simultaneous equations framework, we investigate the relationship between bank regulatory capital and bank liquidity measured from on-balance sheet positions for European and US publicly traded commercial banks. Previous research studying the determinants of bank capital buffer has neglected the role of liquidity. On the whole, we find that banks decrease their regulatory capital ratios when they face higher illiquidity as defined in the Basel III accords or when they create more liquidity as measured by Berger and Bouwman (2009). However, considering other measures of illiquidity that focus more closely on core deposits in the United States, our results show that small banks strengthen their solvency standards when they are exposed to higher illiquidity. Our empirical investigation supports the need to implement minimum liquidity ratios concomitant to capital ratios, as stressed by the Basel Committee; however, our findings also shed light on the need to further clarify how to define and measure illiquidity and also on how to regulate large banking institutions, which behave differently than smaller ones.     

Capital shocks, bank asset allocation, and the revised Basel Accord

In contrast to the 1988 Basel Accord (Basel I), the revised risk-based capital standards (Basel II) propose regulatory capital requirements based on credit ratings. This paper develops a theoretical model to analyze how banks will adjust their low and high credit risk commercial loans under the proposed newer standard. Capital-constrained banks respond to an adverse capital shock by reducing high credit risk loans, while under certain circumstances, low credit risk loans may actually increase. When compared to Basel I, it is shown that high-risk loans are reduced more under Basel II, but whether a bank reduces total lending more under Basel I or under the revised standards depends on a complex interaction of factors.     

A practical approach to validating a PD model

The capital adequacy framework Basel II aims to promote the adoption of stronger risk management practices by the banking industry. The implementation makes validation of credit risk models more important. Lenders therefore need a validation methodology to convince their supervisors that their credit scoring models are performing well. In this paper we take up the challenge to propose and implement a simple validation methodology that can be used by banks to validate their credit risk modelling exercise. We will contextualise the proposed methodology by applying it to a default model of mortgage loans of a commercial bank in the Netherlands.     

巴塞尔协议Ⅲ及其对我国中小银行影响研究

《巴塞尔协议Ⅲ》规定了最低资本充足率要求,资本缓冲额度,反周期超额资本要求,风险资本杠杆率,监督检查和信息披露项目条款以便提高银行抗御风险能力。文章通过分析新协议对我国中小银行的影响,并提出了可行性应对策略,以便中小银行能够审慎和有效的实践新协议,从而在面对金融危机时能够立于不败之地。     

商业银行资本工具创新及定价研究

资本工具的创新可以拓展银行资本补充渠道和空间,提升银行补充资本的能力,强化银行业的资本约束,增强风险管理水平,推动商业银行业务转型,增强服务实体经济的能力.本文在阐述我国资本工具的应用及创新背景的基础上,通过建立二叉树模型,探讨了我国新型资本工具定价问题并提出相关建议.     

Minimizing Basel III Capital Requirements with Unconditional Coverage Constraint

The new Basel III framework increases the banks’ market risk capital requirements. In this paper, we introduce a new risk management approach based on the unconditional coverage test to minimize the regulatory capital requirements. Portfolios optimized with our new minimum capital constraint successfully reduce the Basel III market risk capital requirements. In general, portfolios with value-at-risk and conditional-value-at-risk objective functions and underlying empirical distribution yield better portfolio risk profiles and have lower capital requirements. For the optimization we use the threshold-accepting heuristic and the common trust-region search method.     

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.     

The pernicious effects of contaminated data in risk management

Banks hold capital to guard against unexpected surges in losses and long freezes in financial markets. The minimum level of capital is set by banking regulators as a function of the banks’ own estimates of their risk exposures. As a result, a great challenge for both banks and regulators is to validate internal risk models. We show that a large fraction of US and international banks uses contaminated data when testing their models. In particular, most banks validate their market risk model using profit-and-loss (P/L) data that include fees and commissions and intraday trading revenues. This practice is inconsistent with the definition of the employed market risk measure. Using both bank data and simulations, we find that data contamination has dramatic implications for model validation and can lead to the acceptance of misspecified risk models. Moreover, our estimates suggest that the use of contaminated data can significantly reduce (market-risk induced) regulatory capital.     

Banks’ capital buffer,risk and performance in the Canadian banking system: Impact of business cycles and regulatory changes

Using quarterly financial statements and stock market data from 1982 to 2010 for the six largest Canadian chartered banks, this paper documents positive co-movement between Canadian banks’ capital buffer and business cycles. The adoption of Basel Accords and the balance sheet leverage cap imposed by Canadian banking regulations did not change this cyclical behavior of Canadian bank capital. We find Canadian banks to be well-capitalized and that they hold a larger capital buffer in expansion than in recession, which may explain how they weathered the recent subprime financial crisis so well. This evidence that Canadian banks ride the business and regulatory periods underscores the appropriateness of a both micro- and a macro-prudential “through-the-cycle” approach to capital adequacy as advocated in the proposed Basel III framework to strengthen the resilience of the banking sector.     

Modelling the economic value of credit rating systems

In this paper we develop a model of the economic value of credit rating systems. Increasing international competition and changes in the regulatory framework driven by the Basel Committee on Banking Supervision (Basel II) called forth incentives for banks to improve their credit rating systems. An improvement of the statistical power of a rating system decreases the potential effects of adverse selection, and, combined with meeting several qualitative standards, decreases the amount of regulatory capital requirements. As a consequence, many banks have to make investment decisions where they have to consider the costs and the potential benefits of improving their rating systems. In our model the quality of a rating system depends on several parameters such as the accuracy of forecasting individual default probabilities and the rating class structure. We measure effects of adverse selection in a competitive one-period framework by parameterizing customer elasticity. Capital requirements are obtained by applying the current framework released by the Basel Committee on Banking Supervision. Results of a numerical analysis indicate that improving a rating system with low accuracy to medium accuracy can increase the annual rate of return on a portfolio by 30–40 bp. This effect is even stronger for banks operating in markets with high customer elasticity and high loss rates. Compared to the estimated implementation costs banks could have a strong incentive to invest in their rating systems. The potential of reduced capital requirements on the portfolio return is rather weak compared to the effect of adverse selection.     

The cyclical effects of the Basel II capital requirements

Capital requirements play a key role in the supervision and regulation of banks. The Basel Committee on Banking Supervision is in the process of changing the current framework by introducing risk sensitive capital charges. Some fear that this will unduly increase the volatility of regulatory capital. Furthermore, by limiting the banks’ ability to lend, capital requirements may exacerbate an economic downturn. The paper examines the problem of capital-induced lending cycles and their pro-cyclical effect on the macroeconomy in greater detail. It finds that the capital buffer that banks hold on top of the required minimum capital plays a crucial role in mitigating the impact of the volatility of capital requirements.     

Regulations and Productivity Growth in Banking: Evidence from Transition Economies

This paper examines the relationship between the regulatory and supervision framework, and the productivity of banks in 22 countries over the period 1999–2009. We follow a semiparametric two‐step approach that combines Malmquist index estimates with bootstrap regressions. The results indicate that regulations and incentives that promote private monitoring (PMON) have a positive impact on productivity. Restrictions on banks’ activities relating to their involvement in securities, insurance, real estate, and ownership of nonfinancial firms also have a positive impact. Regulations relating to the first and second pillars of Basel II, namely, capital requirements (CAPR) and official supervisory power (SPR) do not have, in general, a statistically significant impact on productivity over the study period although they appear to gain in importance following the onset of the financial crisis in 2007. The latter finding indicates that stringent capital and supervisory standards have positive productivity effects when financial pressures peak. Our results are robust when controlling for various country‐specific features and alternative estimation approaches.     

Private equity and regulatory capital

Regulatory capital requirements for European banks have been put forward in the Basel II Capital Framework and subsequently in the capital requirements directive (CRD) of the EU. We provide a detailed discussion of the capital requirements for private equity investments under different approaches. For the internal model approach we present a structural model that we calibrate to a proprietary dataset. We modify the standard Merton structural model to make it applicable in practice and to capture stylized facts of private equity investments. We also implement the early default feature with a fast simulation algorithm. Our results support capital requirements lower than in Basel II, but not as low as in CRD, thereby giving adverse incentives to banks for using advanced risk models. A sensitivity analysis shows that this finding is robust to parameter uncertainty and stress scenarios.     

The Basel Committee proposals for a new capital accord: implications for Italian banks

Following a few general considerations on the recently proposed revision of the Basel Agreement on capital adequacy, this paper focuses on the first pillar of the Basel Committee proposals, the handling of capital requirements for credit risk in the banking book. The Basel Committee envisages an approach alternatively based on external ratings or on internal rating systems for the determination of the minimum capital requirement related to bank loan portfolios. This approach supports a system of capital requirements that is more sensitive to credit risk. On the basis of specific assumptions, these requirements provide a measure of the value at risk (VaR) produced by models used by major international banks. We first address the impact of the standardised and (internal ratings-based) IRB foundation approach using general data on Italian banks loans' portfolios default rates. We then simulate the impact of the proposed new rules on the corporate loan portfolios of Italian banks, using the unique data set of mortality rates recently published by the Bank of Italy. Three main conclusions emerge from the analysis: (i) the standardised approach implicitly penalizes Italian banks in their interbank funding as their rating is generally below AA/Aa, (ii) the average default rate experienced by Italian banks is higher than the one implied in the benchmark risk weight (BRW) proposed by the Basel Committee for the IRB foundation approach, thereby potentially leading to an increase in the regulatory risk weights, and (iii) the risk-weight is based on an average asset correlation that is significantly higher than the one historically recorded within the Italian banks' corporate borrowers. These findings support the need for a significant revision of the basic inputs and assumptions of the Basel proposals. Finally, in relation to the conditions that allow the capital market to effectively discipline banks, we comment on the proposals advanced in relation to the third pillar of the new capital adequacy scheme.     

Bank Capital Regulation of Trading Portfolios: An Assessment of the Basel Framework

In setting minimum capital requirements for trading portfolios, the Basel Committee on Banking Supervision (1996, 2011a, 2013) initially used Value‐at‐Risk (VaR), then both VaR and stressed VaR (SVaR), and most recently, stressed Conditional VaR (SCVaR). Accordingly, we examine the use of SCVaR to measure risk and set these requirements. Assuming elliptically distributed asset returns, we show that portfolios on the mean‐SCVaR frontier generally lie away from the mean‐variance (M‐V) frontier. In a plausible numerical example, we find that such portfolios tend to have considerably higher ratios of risk (measured by, e.g., standard deviation) to minimum capital requirement than those of portfolios on the M‐V frontier. Also, we find that requirements based on SCVaR are smaller than those based on both VaR and SVaR but exceed those based on just VaR. Finally, we find that requirements based on SCVaR are less procyclical than those based on either VaR or both VaR and SVaR. Overall, our paper suggests that the use of SCVaR to measure risk and set requirements is not a panacea.     

Incentives and financial crises: Microfounded macroprudential regulation

We provide a micro-based rationale for macroprudential capital regulation of financial intermediaries (banks) by developing a model in which bankers can privately undertake a costly effort and reduce the probability of adverse shocks to their asset holdings that force liquidation (deterioration risk). A decline in the fundamental risk of assets ameliorates funding conditions, boosting the banks’ ability to expand their balance sheets. In principle, a higher continuation value would improve incentives to put effort. However, the rise in asset demand and prices also increases the payoff in liquidation, eventually reducing the equilibrium optimal effort. Poor incentives impose socially inefficient liquidation and can be corrected through a regulatory capital requirement. We show that the requirement should be high when fundamental risk is low. Therefore, the model suggests a theoretical foundation for macroprudential regulation and the countercyclical capital buffer of Basel III.     

Financial stability and Basel II

The Basel II Advanced Internal Ratings (AIRB) approach is compared to capital requirements set using an equilibrium structural credit risk model. Analysis shows the AIRB approach undercapitalizes credit risk relative to regulatory targets and allows wide variation in capital requirements for a given exposure owing to ambiguity in the definitions of loss given default and exposure at default. In contrast, the Foundation Internal Ratings Based (FIRB) approach may over-capitalize credit risk relative to supervisory objectives. It is unclear how Basel II will buttress financial sector stability as it specifies the weakest regulatory capital standard for large complex AIRB banks.      

The regulations–risk taking nexus under competitive pressure: What about the Islamic banking system?

Does market power condition the effect of bank regulations and supervision on bank risk taking? We focus on three regulatory tools: capital requirements, the restriction of activities, and official supervisory powers. Employing 10 years of unbalanced panel data on 123 Islamic and conventional banks operating in the Middle East and Asia, we arrive at the following conclusions. First, banking market power strengthens the negative impact of capital regulation on bank risk taking. Second, our empirical results suggest that the negative effect of activity restrictions on stability is diminished when banks have greater market power. Finally, we do not find strong evidence that the negative effect of supervisory power on banks’ risk taking is conditioned by their competitive behavior. In further analysis, we differentiate between Islamic and conventional banks regarding their competition, as well as their risk behavior. The results differ according to the banking business model. These findings could be useful for bank regulators in light of the accomplishment of Islamic banks’ regulatory framework. Indeed, the adoption of Basel III represents a significant regulatory challenge, given that it does not take into account the specificities of Islamic banks.