The Definition of the Grading Scales in Banks' Internal Rating Systems

An internal risk rating system can be defined as the process used to classify bank borrowers into categories of different credit riskiness. Most of the related literature has investigated various aspects of this process, but the problem of defining the categories and the distribution of borrowers into the different classes or grades has received rather less attention, other than noting that the number of grades and their dispersion should achieve a meaningful differentiation of risk. An appropriate definition of the grading scale is of primary importance because the probability of default associated to each grade is the key inputs of capital allocation systems at many best-practice banks and is the core of the January 2001's new proposal of the Basel Committee for the calculation of capital requirements. Statistical techniques such as cluster analysis can help in identifying distinct subgroups of borrowers possessing the same creditworthiness. We use a logit model to estimate individual default probabilities for four categories of borrowers and apply cluster analysis to assign borrowers to each grade. However, since cluster analysis is not a purely mechanical process, but requires examination of the nature of observations and of the objective of clustering, the ultimate choice of the most appropriate grading scale for a given portfolio relies on empirical grounds. A sufficient granularity and an appropriate quantification of risk must be balanced.
(J.E.L.: G21, G22, G33)     

Rating Agency Actions and the Pricing of Debt and Equity of European Banks: What Can we Infer About Private Sector Monitoring of Bank Soundness?

The recent consultative papers by the Basel Committee on Banking Supervision has raised the possibility of an explicit role for external rating agencies in the assessment of the credit risk of banks' assets, including interbank claims. Any judgement on the merits of this proposal calls for an assessment of the information contained in credit ratings and its relationship to other publicly available information on the financial health of banks and borrowers. We assess this issue via an event study of rating change announcements by leading international rating agencies, focusing on rating changes for European banks for which data on bond and equity prices are available. We find little evidence of announcement effects on bond prices, which may reflect the lack of liquidity in bond markets in Europe during much of our sample period. For equity prices, we find strong effects of ratings changes, although some of our results may suffer from contamination by contemporaneous news events. We also test for pre-announcement and post-announcement effects, but find little evidence of either. Overall, our results suggest that ratings agencies may perform a useful role in summarizing and obtaining non-public information on banks and that monitoring of banks' risk through bond holders appears to be relatively limited in Europe. The relatively weak monitoring by bondholders casts some doubt on the effectiveness of a subordinated debt requirement as a supervisory tool in the European context, at least until bond markets are more developed.
(J.E.L.: E53, G21, G33)     

Measuring systemic risk using vine-copula

We present an intuitive model of systemic risk to analyse the complex interdependencies between different borrowers. We characterise systemic risk by the way that financial institutions are interconnected. Using their probability of default, we classify different international financial institutions into five rating groups. Then we use the state-of-the-art canonical (C-) and D-vine copulae to investigate the partial correlation structure between the rating groups. Amongst many interesting findings, we discover that the second tier financial institutions pay a larger contribution to the systemic risk than the top tier borrowers. Further, we discuss an application of our methodology for pricing credit derivative swaps.     

Joint liability among bank borrowers

Summary. A common feature of financial intermediaries is that the welfare of one borrower is adversely affected by the poor performance of other borrowers. That is, there exists a degree of joint liability among the borrowers of a financial intermediary. This paper provides an explanation for this observation. It demonstrates that in Krasa and Villamil's [14] formalization of a financial intermediary as a delegated monitor, intermediation with joint liability between borrowers Pareto dominates intermediation without joint liability.Received: 4 September 2002, Revised: 21 March 2003, JEL Classification Numbers: D8, E5, G2, G3.I am particularly indebted to Douglas Diamond and Robert Townsend for their advice on this paper. I thank an anonymous referee for helpful comments.     

Adverse selection as an explanation of credit rationing and different lender types

An adverse selection model is utilized to demonstrate that informational asymmetry may make it wealth optimal for the financial intermediary (FI) to credit ration and to rationalize the existence of different lenders in the credit market. The crucial assumption is that borrowers differ in their tolerance for a lender-imposed default penalty, the severity of which also varies with the lender. The credit rationing portion proves that the FI will: 1) be forced by a binding regulatory constraint to overinvest in capital; 2) ration its worst risk class borrowers; 3) establish its optimal loan interest rate on the basis of the average quality of its loans and the interest rate elasticity of the borrower demand in its best risk category; and 4) decrease the total loan volume and increase the loan interest rate due to an increase in the capital requirement, but the effect on the default risk quality of its loan portfolio is ambiguous. The existence result is that if a lender has a high default penalty, he can charge a lower rate and attract only “good” borrowers, i.e., heterogeneous lender types encourage the screening of borrowers and vice versa.     

Screening, cross-border banking, and the allocation of credit

The author analyses competition among banks when banks can use creditworthiness tests that generate (imperfect) information about borrowers. When banks can strategically adjust the test characteristics by investing resources in the screening technology, he shows that credit markets are not easily contestable. An increase in the intensity of competition may have few effects on incumbents» conduct and overall market shares. Moreover, conditions are provided under which screening efforts are reduced by competition. In such situations the quality of the overall loan portfolio declines and the economy incurs higher aggregate risk due to the lower quality of banks» information production. The welfare gains from integrating fragmented loan markets can actually be negative.     

A costly state verification model with diversity of opinions

Summary. In simple models of borrowing and lending with ex-post asymmetric information, Gale and Hellwig (1985) and Williamson (1986) have shown that optimal debt contracts are simple debt contracts where borrowers repay a fixed interest rate whenever possible and lenders seize all the profit when borrowers default. In this note, we depart from their works by assuming that borrowers and lenders have heterogeneous beliefs, and show that simple debt contracts do not necessarily survive as optimal contracts.JEL Classification Numbers: G3, D8.     

Borrower credit access and credit performance after loan modifications

While the preventive effect of loan modifications on mortgage default has been well-documented, evidence on the broad consequences of modifications has been fairly limited. Based on two unique loan-level data sets with borrower credit profiles, this study reports novel empirical evidence on how homeowners manage their credit before and after receiving modifications. The paper has several main findings. First, loan modifications improve borrowers’ overall credit standing and access to credit. Modifications that provide principal reduction, rate reduction, or greater payment relief, as well as those received by borrowers not in financial catastrophe, lead to a larger improvement in borrowers’ credit rating than others. Second, loan modifications lead to a slight increase in borrowers’ debts, primarily on home equity line of credit accounts and auto loans. Third, borrowers’ performance on nonmortgage accounts, however, has not been negatively impacted by modifications. This study demonstrates that interventions designed to improve household balance sheets could have a direct and sizeable impact on borrower financial outcomes.     

Time to change. Rating changes and policy implications

The recent financial crisis manifested the criticism to rating agencies of being slow in adjusting their rating to current conditions. This paper examines the timeliness of rating changes and identifies factors which result in ‘stickiness’ of rating actions. Knowledge of the stickiness of rating agencies is a first step in designing a more appropriate rating system. Stickiness is characterized by not adjusting the rating even when a market-based estimate of default probability changes. Extending an econometric model of friction the migration policy is modelled in terms of thresholds which have to be crossed by default probability estimates before an up- or downgrade occurs. Default probability estimates have to change by two notches before the rating agency reacts. The timeliness differs across the rating spectrum and over the years. During periods with high defaults and for low credit quality firms agencies tend to rate more timely.     

The suspension of borrowing: an implicit penalty for loan default under imperfect information

A credit seeker may be suspended from borrowing for a period of time due to a previous default. Such suspension is widely used in bank lending through credit check. Our work analyses the effects of suspension on the investment choice of borrowers under uncertainty and on the lending policy of banks facing asymmetric information. We show that suspension should be tightened at low loan rates, but loosened otherwise, to improve the repayment performance of borrowers. We also show that although credit rationing may not be completely removed due to imperfect information, the excess demand for credit or transitive waiting in the market can actually be attenuated by such efficient use of suspension. Our theoretical predictions are consistent with observed cyclical patterns of changes in lendingrates and suspension severity.     

Natural or unnatural selection? The end of lending relationships for small businesses

We investigate the situation where small business borrowers and banks end their lending relationships. If credit allocation is efficient, banks terminate their relationships with risky borrowers. Alternatively, small business borrowers are more likely to end their relationships when they have poor investment opportunities and do not require borrowed funds. However, if the soft budget constraints of banks or credit crunches are a significant problem, banks are likely to continue their relationships with risky firms or end their relationships with nonrisky firms, which is representative of an unnatural credit allocation. Using Japanese firm-level data, we show empirically that these relationships end naturally, with natural credit allocation supported even during the recent global financial crisis.     

CREDIT RATING AND DEBT CRISES

We develop an equilibrium theory of credit rating in the presence of rollover risk. By influencing rational creditors, ratings affect sovereigns' probability of default, which in turn affects ratings. Our analysis reveals a pro‐cyclical impact of credit rating: In equilibrium the presence of a rating agency increases default risk when it is high and decreases default risk when it is low.     

Prediction of bank financial strength ratings: The case of Turkey

Bank financial strength ratings have gained widespread popularity especially after the recent financial turmoil. Rating agencies were criticized because of their ratings and failure to predict the bankruptcy of the banks. Based on this observation, we investigate whether the forecast of the rating of bank's financial strength using publicly available data is consistent with those of the credit rating agency. We use the data of Turkish banks for this investigation. We take a country-specific approach because previous studies found that proxies used for environmental factors (political, economic, and financial risk of the country) did not have any explanatory power and it is hard to find international data for other important factors such as franchise value, concentration, and efficiency. We use two popular multivariate statistical techniques (multiple discriminant analysis and ordered logistic regression) to estimate a suitable model and we compare their performances with those of two mostly used data mining techniques (Support Vector Machine and Artificial Neural Network). Our results suggest that our predictions are consistent with those of Moody's financial strength rating in general.. The important factors in rating are found to be profitability (measured by return on equity), efficient use of resources, and funding the businesses and the households instead of the government that shows efficient placement of the funds.     

Peer Group Formation in an Adverse Selection Model

This paper develops an adverse selection model where peer group systems are shown to trigger lower interest rates and remove credit rationing in the case where borrowers are uninformed about their potential partners and ex post state verification (or auditing) by banks is costly. Peer group formation reduces interest rates due to a 'collateral effect', namely, cross subsidisation amongst borrowers acts as collateral behind a loan. By uncovering such a collateral effect, this paper shows that peer group systems can be viewed as an effective risk pooling mechanism, and thus enhance efficiency, not just in the full information set up.     

The stability of generalised stackelberg equilibria in heterogeneous oligopoly

Conclusions In this paper we have derived sufficient conditions for the stability of the G. S. E. These conditions follow from the condition on the stability of the G. C. E., given by Okuguchi (1978).When the conditions for asymptotic stability are fulfilled, the existence of the G. S. E. may be demonstrated in the same way as the existence of the G. C. E. has been demonstrated by Okuguchi (1978), that is: the G. S. E. is the fixpoint of a contracting mapping. In the case of linear demand functions and quadratic cost functions we have found the rather strong result that the sufficient conditions for (asymptotic) stability of the G. C. E. imply the (asymptotic) stability of the G. S. E. as well.This conclusion may be surprising to followers of Stackelberg. Mostly the outcome of a Stackelberg oligopoly is considered as adisequilibrium.In this paper we have made clear that a firm maximizing expected profit and using a generalised Stackelberg strategy, like a firm using a generalised Cournot strategy, only correctly predicts inequilibrium the price of the other firms. (See also on this point Heertje and Furth (1979)).When the outcome of a G. S. E. gives one or more firms less profit than in a G. C. E. then they expect, any price change, under-taken by them, will lower their expected profit even more.I would like to thank Prof. Dr. A. Heertje and an anonymous referee for their useful comments on earlier drafts of this paper and D. Weatherall for his remarks on the english of the text.     

Evaluating credit risk and loan performance in online Peer-to-Peer (P2P) lending

Online Peer-to-Peer (P2P) lending has emerged recently. This micro loan market could offer certain benefits to both borrowers and lenders. Using data from the Lending Club, which is one of the popular online P2P lending houses, this article explores the P2P loan characteristics, evaluates their credit risk and measures loan performances. We find that credit grade, debt-to-income ratio, FICO score and revolving line utilization play an important role in loan defaults. Loans with lower credit grade and longer duration are associated with high mortality rate. The result is consistent with the Cox Proportional Hazard test which suggests that the hazard rate or the likelihood of the loan default increases with the credit risk of the borrowers. Finally, we find that higher interest rates charged on the high-risk borrowers are not enough to compensate for higher probability of the loan default. The Lending Club must find ways to attract high FICO score and high-income borrowers in order to sustain their businesses.     

Debt financing,soft budget constraints,and government ownershipEvidence from China1

Debt financing is expected to improve the quality of corporate governance, but we find, using a large sample of public listed companies (PLCs) from China, that an increase in bank loans increases the size of managerial perks and free cash flows and decreases corporate efficiency. We find that bank lending facilitates managerial exploitation of corporate wealth in government‐controlled firms, but constrains managerial agency costs in firms controlled by private owners. We argue that the failure of corporate governance may derive from the shared government ownership of lenders and borrowers, which nurtures soft budget constraints.     

The Impact of the Rating Agencies' Through‐the‐cycle Methodology on Rating Dynamics

Surveys on the use of agency credit ratings reveal that some investors believe that credit‐rating agencies are relatively slow in adjusting their ratings. A well‐accepted explanation for this perception on rating timeliness is the through‐the‐cycle methodology that agencies use. Through‐the‐cycle ratings are intended to measure default risk over long investment horizons and to respond only to changes in the permanent component of credit quality. A second aspect of the through‐the‐cycle methodology is the prudent migration policy. In a benchmark study with a financial ratio‐based credit‐scoring models – an agency‐rating prediction model and default‐prediction models with various time horizons – we confirm the exclusive focus of agencies on the permanent component of credit quality and we model and quantify the agencies' prudent migration policy. A rating migration is triggered only when the rating predicted by the agency‐rating prediction model differs by at least a threshold level of 1.8 notch steps from the actual agency rating. If triggered, ratings are only partly adjusted by 70 per cent at the downside and 60 per cent at the upside. From a 1‐year point‐in‐time perspective, weighting temporary fluctuations in credit quality, the through‐the‐cycle methodology lowers the rating‐migration probability by a factor of 3.5. Both aspects of the through‐the‐cycle methodology contribute equally to this factor. The partial adjustment of ratings lowers the rating‐reversal probabilities on short term and introduces rating drift, the known serial correlation in agency‐rating migrations.     

评级机构竞争、声誉与债券信用评级质量

本文以我国2010—2014年的企业债和公司债为样本,构建了新的声誉指标,分析了声誉机制和评级机构竞争对债券信用评级质量的作用机理。结果表明：高声誉的评级机构出具的债券信用评级具有较高的评级质量;评级机构竞争加剧了评级虚高,降低了债券信用评级质量;声誉机制能够抑制评级机构竞争导致的评级虚高,提高债券信用评级质量。本文为衡量我国评级机构声誉提供了新的视角,有助于辩证地看待评级机构竞争的影响。