A macro stress test model of credit risk for the Brazilian banking sector

This paper proposes a model to conduct macro stress test of credit risk for the banking sector based on scenario analysis. We employ an original bank-level data set that splits bank credit portfolios in 21 granular categories, covering household and corporate loans. The results corroborate the presence of a strong procyclical behavior of credit quality, and show a robust negative relationship between the logistic transformation of non-performing loans (NPLs) and GDP growth, with a lag response of up to three quarters. The results also indicate that the procyclical behavior of loan quality varies across credit types. This is novel in the literature and suggests that banks with larger exposures to highly procyclical credit types and economic sectors would tend to undergo sharper deterioration in the quality of their credit portfolios during an economic downturn. Lack of sufficient portfolio granularity in macro stress testing fails to capture these effects and thus introduces a source of bias that tends to underestimate the tail losses stemming from the riskier banks in a system.     

Stress testing German banks against a global credit crunch

This paper investigates the impact of a global credit crunch on the corporate credit portfolios of large German banks using a two-stage approach. First, a macroeconometric simulation model (NiGEM) is used to forecast the impact of a substantial increase in the cost of business capital for firms worldwide in three particularly export-oriented industry sectors in Germany. Second, the impact of this economic multi-sector stress on bank credit portfolios is captured by a state-of-the-art Credit Metrics-type portfolio model with sector-dependent unobservable risk factors as drivers of the systematic risk. In our assessment of capital ratios, we confirm that both the increase of the capital charge for the unexpected loss and the increase in banks’ expected losses need to be considered. We also find that the availability of granular information at the level of borrower-specific probabilities of default has a significant impact on the stress test results.     

The credit quality channel: Modeling contagion in the interbank market

We propose an algorithm to model contagion in the interbank market via what we term the “credit quality channel”. In existing models on contagion via interbank credit, external shocks to banks often spread to other banks only in case of a default. In contrast, shocks are transmitted also via asset devaluations and deteriorations in the credit quality in our algorithm. First, the probability of default (PD) of those banks directly affected by some shock increases. This increases the expected loss of the credit portfolios of the initially affected banks’ counterparties, thereby reducing the counterparties’ regulatory capital ratio. From a logistic regression we estimate the increase in the counterparties’ PD due to a reduced capital ratio. Their increased PDs in turn affect the counterparties’ counterparties, and so on. This coherent and flexible framework is applied to the bilateral interbank credit exposure of the entire German banking system in order to examine policy questions. For that purpose, we propose to measure the potential cost of contagion of a given shock scenario by the aggregated regulatory capital loss computed in our algorithm.     

An analytic approach to credit risk of large corporate bond and loan portfolios

We derive an analytic approximation to the credit loss distribution of large portfolios by letting the number of exposures tend to infinity. Defaults and rating migrations for individual exposures are driven by a factor model in order to capture co-movements in changing credit quality. The limiting credit loss distribution obeys the empirical stylized facts of skewness and heavy tails. We show how portfolio features like the degree of systematic risk, credit quality and term to maturity affect the distributional shape of portfolio credit losses. Using empirical data, it appears that the Basle 8% rule corresponds to quantiles with confidence levels exceeding 98%. The limit law's relevance for credit risk management is investigated further by checking its applicability to portfolios with a finite number of exposures. Relatively homogeneous portfolios of 300 exposures can be well approximated by the limit law. A minimum of 800 exposures is required if portfolios are relatively heterogeneous. Realistic loan portfolios often contain thousands of exposures implying that our analytic approach can be a fast and accurate alternative to the standard Monte-Carlo simulation techniques adopted in much of the literature.     

Do capital flows change domestic credit allocation?

Since the 1990s, domestic bank credit has been reallocated away from lending to non-financial business and toward households. An expanding literature discusses negative effects on growth and stability of this change in credit allocation. We research its drivers. We hypothesize that if foreign capital flows into economies with few investment opportunities, it may substitute for domestic bank lending to non-financial business, so that bank balance sheets become more dominated by household lending. In GMM estimations on data for 36 economies over 1990–2011, we find evidence consistent with this mechanism. Foreign capital inflows into the non-bank sector (but not into the bank sector) are associated with lower shares of business lending in domestic bank portfolios. The association is weaker in economies with more investment opportunities, whether proxied by investment shares, current account surpluses, or EMU membership. Our results highlight the importance of sectoral destination in determining the effects of capital flows.     

Cyclical correlations, credit contagion, and portfolio losses

We model aggregate credit losses on large portfolios of financial positions contracted with firms subject to both cyclical default correlation and direct default contagion processes. Cyclical correlation is due to the dependence of firms on common economic factors. Contagion is associated with the local interaction of firms with their business partners. We provide an explicit normal approximation of the distribution of portfolio losses. We quantify the relation between the variability of global economic fundamentals, strength of local firm interaction, and the fluctuation of losses. We find that cyclical oscillations in fundamentals dominate average losses, while local interaction causes additional fluctuations of losses around their average. The strength of the contagion-induced loss variability depends on the complexity of the business partner network.     

Credit Risk Versus Capital Requirements under Basel II: Are SME Loans and Retail Credit Really Different?

Under Basel II, retail and SME credit (R&SME) receive special treatment because of a supposedly smaller exposure to systemic risk. Most research on this issue has been based on parameterized credit risk models. We present new evidence by applying Carey's (Carey, Mark. “Credit Risk in Private Debt Portfolios.” Journal of Finance 53, no. 4 (1998), 1363–1387.) nonparametric Monte-Carlo resampling method to two banks' complete loan portfolios. By exploiting that a sub-sample of all borrowers has been assigned an internal rating by both banks, we can compare the credit loss distributions for the three credit types, and compute both economic and regulatory capital under Basel II. We also test if our conclusions are sensitive to the definitions of R&SME credit. Our findings show that R&SME portfolios are usually riskier than corporate credit. Special treatment under Basel II is thus not justified. JEL classification: C14, C15, G21, G28, G33.     

Competitive effects of Basel II on US bank credit card lending

We analyze the potential competitive effects of the proposed Basel II capital regulations on US bank credit card lending. We find that bank issuers operating under Basel II will face higher regulatory capital minimums than Basel I banks, with differences due to the way the two regulations treat reserves and gain-on-sale of securitized assets. During periods of normal economic conditions, this is not likely to have a competitive effect; however, during periods of substantial stress in credit card portfolios, Basel II banks could face a significant competitive disadvantage relative to Basel I banks and nonbank issuers.     

Ratings-based credit risk modelling: An empirical analysis

Banks have recently developed new techniques for gauging the credit risk associated with portfolios of illiquid and defaultable instruments. These techniques could revolutionise banks' management of credit risk and could in the longer term serve as a more risk-sensitive basis for calculating regulatory capital on banks' loan books than in Basel 2, the new regulatory capital framework. In this paper we implement a popular credit risk model that exploits the information in credit ratings to determine a portfolio's value-at-risk. Using price data on large eurobond portfolios, we assess, on an out-of-sample basis, how well the model tracks the risks it is supposed to measure.     

Risk-Based Capital and Credit Insurance Portfolios

This paper analyzes the risk-management practices of a vulnerable credit insurer by studying the effects of time-varying correlations, asset risks and loan maturities on the risk-based capital that backs credit insurance portfolios. Since asset correlations may change over a business cycle, we have analyzed these effects by means of a one-factor Gaussian stochastic model as part of an extended contingent claims analysis. Our results show the need to account for cyclical changes to correlations in the pricing of credit insurance. When compared with the reserve of risk-based capital recommended by the Basel II Internal Ratings-Based (IRB) approach, our model provides a better capital buffer against extreme credit losses, especially in times of recession and/or in a risky business environment. Using a risk-adjusted performance metric (RAPM), we find insurers perform better when insuring relatively short-term loans. We also make several policy recommendations on creating a reserve of risk-based capital to protect against possible loan losses.     

消费信贷与家庭人力资本投资

已有丰富的文献考察了消费信贷对家庭消费和投资行为的影响，但少有研究关注其对家庭人力资本投资的影响。家庭人力资本投资对于人力资本积累、经济高质量发展至关重要。基于此，本文考察了信用卡使用对家庭人力资本投资的影响及其影响机制，主要发现如下：信用卡使用显著增加了家庭人力资本投资，且这一效应具有长期动态影响并对城市、高收入、高教育程度家庭影响更为显著，这意味着信用卡消费信贷可能会增加人力资本不平等。进一步研究发现，家庭会增加劳动力供给来应对人力资本支出的增加。机制分析表明，信用卡使用主要通过增加家庭消费投资、促进消费升级、缓解家庭预算约束三种途径促进家庭人力资本投资。在风险可控的前提下，引导消费信贷流向有利于实体经济发展的领域，可助力于消费升级与人力资本积累，从而为经济发展提供新动能。     

Economic and regulatory capital allocation for revolving retail exposures

We present two internal capital allocation models and compare the capital ratios they generate with those prescribed by the latest revision of Basel’s New Capital Accord proposal for advanced retail portfolios, which allows for explicit future margin income recognition. Given a test portfolio of credit card exposures that we assemble, we find that Basel’s ratios are closer to those generated by our models for low credit risk segments. We attribute the discrepancies to the different ways Basel and our models account for future margin income, to Basel’s assumptions about asset correlations and to one model taking macroeconomic conditions into account.     

人力资本偏向金融部门如何影响实体经济增长？

通过构建一个包含银行和生产性企业的两部门增长模型,本文系统考察人力资本偏向金融部门如何影响实体经济增长,并利用2008年中国经济普查数据、2003-2015年地级市数据及2011-2013年中国工业企业数据开展实证检验。理论分析表明,人力资本在金融部门与实体部门之间的配置结构对实体经济增长存在两种效应,依次为资本“挤入”效应和创新“挤出”效应,进而导致人力资本配置情况与实体经济增长率之间呈现倒“U”形关系。随后,计量结果为上述理论推断提供了系列经验证据,且机制检验证实人力资本配置到金融部门有助于促进信贷规模扩张。特别地,反事实框架的测算结果显示,人力资本有效配置将提升实体经济增长率约0.45%,而且贡献率随经济发展更加凸显。本文结论表明,应理性看待人力资本向金融部门的不断聚集,不以简单线性关系进行判断,要综合权衡资本“挤入”效应和创新“挤出”效应的相对重要性。     

Bank capital (requirements) and credit supply: Evidence from pillar 2 decisions

We analyze how time-varying bank-specific capital requirements affect bank lending to the non-financial corporate sector as well as banks' balance sheet adjustments. To do so, we relate Pillar 2 capital requirements to a comprehensive corporate credit register coupled with bank and firm balance sheet data. Our analysis consists of three components. First, we investigate how capital requirements affect the supply of bank credit to the corporate sector, both on the intensive and extensive margin, as well as for different types of credit. Subsequently, we document how bank and firm characteristics as well as the monetary policy stance impact the relationship between bank capital requirements and the supply of credit. Finally, we examine how time-varying bank-specific capital requirements affect banks' balance sheet composition.     

Like Father Like Sons? The Cost of Sovereign Defaults in Reduced Credit to the Private Sector

We investigate the impact of sovereign defaults on the ability of the corporate sector in emerging nations to finance itself abroad. We test the hypothesis that sovereign defaults have a negative spillover onto the private sector through credit rationing. We explore a novel data set covering the majority of corporates in emerging nations that received foreign capital between 1880 and 1913. Results confirm that credit rationing existed, was very large, and persisted long beyond the default settlement. The private sector paid a severe cost for their governments’ debt intolerance, with negative implications for their growth.     

An Assessment of Basel II Procyclicality in Mortgage Portfolios

In this paper we develop a probability of default (PD) model for mortgage loans, taking advantage of the Spanish Credit Register, a comprehensive database on loan characteristics and credit quality. From that model, we calculate different types of PDs: point in time, PIT, through the cycle, TTC, average across the cycle and acyclical. Then, we compare capital requirements coming from the different Basel II approaches. We show that minimum regulatory capital under Basel II can be very sensitive to the risk measurement methodology employed. Thus, the procyclicality of regulatory capital requirements under Basel II is an open question, depending on the way internal rating systems are implemented and their output is utilised. We focus on the mortgage portfolio since it is one of the most under researched areas regarding the impact of Basel II and because it is one of the most important of banks’ portfolios.     

信用与资本——开发性金融研究

资本是关系到当下和长远发展的重要命题,而信用是实现从财富到资本转化的关键要素。本文从四个维度考察信用与资本的关系。一是关于信用的产生和演进,指出了信用产生的两个必要条件,并从社会财富三个阶段来审视信用和资本相互作用的演进过程。二是信用的性质和功能。讨论了信用的基本性质,以及规范商品和资本交易、促进资本形成以及信用的金融功能等基础性功能,并进一步讨论了信用的证券化功能以及金融市场建设功能。三是当前信用体系面对的新挑战和新问题。首先提出了美元外汇储备在一定意义上是美元信用对中国储蓄的证券化,是全球信用美元化的组成,在资本匮乏阶段是必要选择,而当下需要对财富和资本寻找新的载体,需要考虑和实现减少对美元的依赖。其次,从深化对国家信用的运用角度对解决问题的路径进行了思考,初步提出了通过发行以国家信用为基础的股权证券化工具,解决长期资本不足问题,应对当前挑战的设想。四是在回顾和总结部分,本文指出,信用的形态会随着资本发展而不断演进,从个人到企业、国家再到国际,从债务信用升级为命运信用即股权信用,乃至尚未出现的国际股权信用,是未来信用发展的方向。     

Haar wavelets-based approach for quantifying credit portfolio losses

This paper proposes a new methodology to compute Value at Risk (VaR) for quantifying losses in credit portfolios. We approximate the cumulative distribution of the loss function by a finite combination of Haar wavelet basis functions and calculate the coefficients of the approximation by inverting its Laplace transform. The Wavelet Approximation (WA) method is particularly suitable for non-smooth distributions, often arising in small or concentrated portfolios, when the hypothesis of the Basel II formulas are violated. To test the methodology we consider the Vasicek one-factor portfolio credit loss model as our model framework. WA is an accurate, robust and fast method, allowing the estimation of the VaR much more quickly than with a Monte Carlo (MC) method at the same level of accuracy and reliability.     

总量型和结构型货币政策工具的选择与搭配——基于结构性去杠杆视角下的分析

本文基于我国34类工业行业的年度数据,识别信贷配置偏向特征对结构性杠杆的影响,以及货币政策应对效应的特征事实:信贷偏向的存在导致不同产权性质企业杠杆变化呈现异质性,这种异质性所产生的结构性杠杆现象因经济周期不同阶段而异,传统总量型货币政策工具难以有效解决结构性杠杆问题。为更深入理解这一现象以及结构性去杠杆下货币政策最优选择问题,本文通过构建一个同时包含信贷配置偏向特征、企业杠杆结构变化特征、总量型与结构型货币政策工具影响特征的DSGE模型进行分析,研究结果表明:总量型货币政策数量工具的宽松操作可以有效应对技术冲击下结构性杠杆问题;总量型工具紧缩资金供给,结合结构型工具定向紧缩,是应对成本推动冲击下结构性高杠杆问题的较好选择;当经济面临风险冲击下结构性杠杆和经济下行并存问题时,需要结构型货币政策数量工具和价格工具同时操作,紧缩国企贷款,同时降低民企融资成本。     

On the Latin American Credit Drivers

We add to the literature about credit in Latin America by assessing what has been driving the recent and heterogeneous expansion of credit to gross domestic product based on supply and demand variables. We chose working with these emerging economies due to the low levels of human capital, the divergent patterns of evolution of economic variables and the vulnerability of credit expansion. According to balanced panel estimations, our main findings in terms of public policy suggest that credit reflects a financial deepening characterized by a higher bank concentration and by a policy able to stimulate saving even practicing lower deposit interest rates.