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.     

The impact of bank consolidation on small business credit availability

This paper examines how banking consolidation has affected small businesses credit. Using the Survey of Small Business Finances, the empirical model examines how credit supply to small firms responds to larger banks, and whether the non-bank supply of credit has offset decreases in credit from banks. Using an empirical model to correct for sample selection, large banks are found to lower the probability of obtaining credit for small businesses, and this lower probability is not offset by increased total loans. Non-bank institutions are found to make up much, but not all, of the decrease.     

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 effect of banking regulation on cross-border lending

Banking regulations often differ between countries: Some regulators require banks to document their evaluation of firms’ creditworthiness, which determines the banks’ choice of lending technology. In a theoretical model, we study how differences in regulation influence competition between domestic and foreign banks and analyze the effect of regulatory harmonization on cross-border lending. We predict that lending rates are lower and access to credit is easier for firms in a border region if the national regulations differ. Using unique bank- and firm-level data from Germany, we show that firms in a border region have better access to credit if regulation differs.     

Do Solicitations Matter in Bank Credit Ratings? Results from a Study of 72 Countries

Would the credit ratings of unsolicited banks be higher if they were solicited? Alternatively, would the credit ratings of solicited banks would be lower if they were unsolicited? To answer these questions, we use an endogenous regime-switching model and data from 460 commercial banks in 72 countries, excluding the United States, for the period 1998–2003. The answer to both questions is yes. Our results show that the observed differences between solicited and unsolicited ratings can be explained by both the solicitation status and financial profile of the banks. This finding is a new contribution to the literature.     

Reject inference in consumer credit scoring with nonignorable missing data

We generalize an empirical likelihood approach to deal with missing data to a model of consumer credit scoring. An application to recent consumer credit data shows that our procedure yields parameter estimates which are significantly different (both statistically and economically) from the case where customers who were refused credit are ignored. This has obvious implications for commercial banks as it shows that refused customers should not be ignored when developing scorecards for the retail business. We also show that forecasts of defaults derived from the method proposed in this paper improve upon the standard ones when refused customers do not enter the estimation data set.     

TARP announcement,bank health,and borrowers’ credit risk

Theory suggests that unhealthy banks exhibit more pronounced flight-to-quality behavior during financial crises and, hence, the infusion of capital through unhealthy banks is less effective in relieving the liquidity shocks of vulnerable borrowers. We test these predictions by investigating how the financial health of leading US banks influenced their borrowers’ credit risk surrounding the announcement of the Troubled Asset Relief Program (TARP). Changes in borrower credit risk, measured by credit default swap (CDS) spreads, should reflect the expected relief from liquidity shocks and other benefits of rescuing banks, such as maintaining the existing lending relationships. Consistent with the theory, prior to the TARP capital infusions, unhealthy banks’ borrowers with high leverage experienced a greater increase in their credit risk relative to similar healthy banks’ borrowers. Following the event, the CDS market anticipated less liquidity relief to these vulnerable unhealthy banks’ borrowers, but more liquidity relief to the vulnerable healthy banks’ borrowers.     

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.     

Economic benefit of powerful credit scoring

We study the economic benefits from using credit scoring models. We contribute to the literature by relating the discriminatory power of a credit scoring model to the optimal credit decision. Given the receiver operating characteristic (ROC) curve, we derive (a) the profit-maximizing cutoff and (b) the pricing curve. Using these two concepts and a mixture thereof, we study a stylized loan market model with banks differing in the quality of their credit scoring model. Even for small quality differences, the variation in profitability among lenders is large and economically significant. We end our analysis by quantifying the impact on profits when information leaks from a competitor’s scoring model into the market.     

A two-stage dynamic credit scoring model,based on customers’ profile and time horizon

As credit card usage has expanded rapidly worldwide, credit scoring has become a very important task for banks, which can benefit from reducing possible risks of default. Credit scoring models help decision makers to decide whether to issue a credit card to a new applicant on the basis of both financial and nonfinancial criteria. The scope of the current study is to develop a dynamic scoring model that (a) estimates the credit performance of an applicant using generalised linear models and (b) accommodates the changes of a borrower's characteristics after the issuance of the credit card and forecasts the time of default using survival analysis.     

Financial constraints of private firms and bank lending behavior

We investigate whether and how financial constraints of private firms depend on bank lending behavior. Bank lending behavior, especially its scale, scope and timing, is largely driven by bank business models which differ between privately owned and state-owned banks. Using a unique dataset on private small and medium-sized enterprises (SMEs) we find that an increase in relative borrowings from local state-owned banks significantly reduces firms’ financial constraints, while there is no such effect for privately owned banks. Improved credit availability and private information production are the main channels that explain our result. We also show that the lending behavior of local state-owned banks can be sustainable because it is less cyclical and neither leads to more risk taking nor underperformance.     

Marking-to-model credit and operational risks of loan commitments: A Basel-2 advanced internal ratings-based approach

Within a marking-to-model framework, this research computes the bank's capital charge for credit and operational risks of loan commitments at Basel-2 fixed audit date. This is done in three steps. The first one prices commitment credit risk as a Gram-Charlier put value and determines the commitment forward-funding proportion. In the second one, put value and funding proportion are combined to compute Basel-2 ‘fair’ capital charge for credit and operational risks. By producing a moderate total capital charge, marking-to-model offers substantial capital relief with respect to the corresponding charge computed with Basel-2 simplified approach. Both charges are however larger than the corresponding nil charge arrived at in Basel-1. In the third step, marking-to-model reveals its flexibility by showing how banks can determine the cost of their exposure to borrowers' credit-rating downgrades and how they can also hedge any exposure to commitment default risk.     

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.     

行为评分模型在个人信用评估应用中的实证研究

本文将Logistic模型和马尔科夫链模型相结合,在Logistic模型的基础上综合考虑客户行为状态的变化,将其加入信用评估模型中,得到优于单一运用Logistic模型的结果,据此得到的动态信用评分,为商业银行信贷决策及客户关系管理决策提供更有力的依据。     

Bank lending during the financial crisis of 2008

This paper shows that new loans to large borrowers fell by 47% during the peak period of the financial crisis (fourth quarter of 2008) relative to the prior quarter and by 79% relative to the peak of the credit boom (second quarter of 2007). New lending for real investment (such as working capital and capital expenditures) fell by only 14% in the last quarter of 2008, but contracted nearly as much as new lending for restructuring (LBOs, M&As, share repurchases) relative to the peak of the credit boom. After the failure of Lehman Brothers in September 2008, there was a run by short-term bank creditors, making it difficult for banks to roll over their short term debt. We find that there was a simultaneous run by borrowers who drew down their credit lines, leading to a spike in commercial and industrial loans reported on bank balance sheets. We examine whether these two stresses on bank liquidity led them to cut lending. In particular, we show that banks cut their lending less if they had better access to deposit financing and thus, they were not as reliant on short-term debt. We also show that banks that were more vulnerable to credit-line drawdowns because they co-syndicated more of their credit lines with Lehman Brothers reduced their lending to a greater extent.     

Information verifiability, bank organization, bank competition and bank-borrower relationships

This paper investigates whether the benefits of bank-borrower relationships differ depending on three factors identified in the theoretical literature: verifiability of information, bank size and complexity, and bank competition. We extend the current literature by analyzing how relationship lending affects loan contract terms and credit availability in an empirical model that simultaneously accounts for all three of these factors. Based on Japanese survey data we find evidence that the benefits from stronger bank-borrower relationships in terms of credit availability are limited to smaller banks. However, when the benefits are measured as improved credit terms, we find little additional benefit, and in some cases increased cost, from stronger relationships for opaque borrowers and for borrowers who get funding from small banks. These latter findings suggest the possibility that relationship borrowers may suffer from capture effects.     

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.     

Credit risk transfer and contagion

Some have argued that recent increases in credit risk transfer are desirable because they improve the diversification of risk. Others have suggested that they may be undesirable if they increase the risk of financial crises. Using a model with banking and insurance sectors, we show that credit risk transfer can be beneficial when banks face uniform demand for liquidity. However, when they face idiosyncratic liquidity risk and hedge this risk in an interbank market, credit risk transfer can be detrimental to welfare. It can lead to contagion between the two sectors and increase the risk of crises.     

Dynamics of Banks' Capital Accumulation

We construct a dynamic neoclassical model of banking capital where the dynamics are governed by the process of financial capital accumulation and credit risk realizations in a structure where stylized banking characteristics are maintained. This is aimed at focusing on how the profit‐maximizing capital ratio of banks evolves and how it reacts to exogenous shocks particularly so during periods of prolonged downturn of the economy. We examine impulse responses of our model to credit risk shock, business cycle shock, and monetary policy shock. The convergence of financial capital to its optimal level is also explored.     

Does banking competition alleviate or worsen credit constraints faced by small- and medium-sized enterprises? Evidence from China

Banking competition may enhance or hinder the financing of small and medium-sized enterprises. Using a survey on the financing of such enterprises in China, combined with detailed bank branch information, we investigate how concentration in local banking market affects the availability of credit. We find that lower market concentration alleviates financing constraints. The widespread presence of joint-stock banks has a larger effect on alleviating these constraints, than the presence of city commercial banks, while the presence of state-owned banks has a smaller effect.